Samriddhi Vaidya Yu Lau Elaine Ho Jie Hao Niklaus P. Lang Nikos Mattheos
Evaluation of the influence exerted by different dental specialty backgrounds and measuring instrument reproducibility on esthetic aspects of maxillary implant-supported single crown
Authors’ affiliations: Samriddhi Vaidya, Yu Lau Elaine Ho, Jie Hao, Niklaus P. Lang, Nikos Mattheos, Implant Dentistry, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR Niklaus P. Lang, Faculty of Dentistry, University of Zurich, Zurich, Switzerland Niklaus P. Lang, Faculty of Dentistry, University of Bern, Bern, Switzerland
Key words: esthetics, implant restoration, modified implant crown aesthetic index, pink
Corresponding author: Nikos Mattheos, DDS, MAS(Perio), PhD Oral Rehabilitation, Faculty of Dentistry The University of Hong Kong 34 Hospital Road, Sai Ying Pun Hong Kong, Hong Kong SAR Tel.: + 852 28590310 Fax: + 852 2858 6114 e-mail: [email protected]
maxillary implants supported single-tooth prosthesis.
esthetic score/white esthetic score Abstract Objective: To evaluate the influence exerted by different dental specialty backgrounds as well as the validity and reproducibility of the Pink Esthetic Score/White Esthetic Score (PES/WES) and the modified Implant Crown Aesthetic Index (mod-ICAI) on the assessment of esthetic aspects of Material and methods: A total of fourteen examiners (Two orthodontists, two prosthodontists, two oral surgeons, two periodontists, two dental technicians, two dental assistants, and two postgraduate students in Implant Dentistry evaluated 20 photographs of single-implant-supported crowns and five photographs of unrestored teeth of esthetic zone in a two part study. The examiners assessed the photographs with each index (Pink Esthetic Score/White Esthetic Score and modified Implant Crown Aesthetic Index), twice with a week’s interval. Orders of photographs were rearranged in the second assessment. Results: Kruskal–Wallis test results showed significant differences among all the six specialties (P ≤ 0.001). DAs and periodontists had significantly better ratings than other specialties with both indices. Prosthodontists had the lowest mean rank scores regardless of the index. Interobserver agreement was also lowest between the two prosthodontists (4–28%), rest of the groups had lowto-moderate agreement (20–80%) when limited allowance was accepted. With mod-ICAI, more interobserver agreement was noted within the specialty group than with PES/WES. Conclusions: The PES/WES and the modified ICAI can be reliable estimates of esthetic outcomes. The assessor degree of specialization affected the esthetic evaluation with both the PES/WES and the modified ICAI. DAs and periodontists were identified to provide more favorable ratings than other specialties while prosthodontists were most critical in this study. With modified ICAI, more interobserver agreement within specialty resulted. The interexaminer agreement may be increased if more tolerance of 1–2 points is considered.
Date: Accepted 29 October 2014 To cite this article: Vaidya S, Ho YLE, Hao J, Lang NP, Mattheos N. Evaluation of the influence exerted by different dental specialty backgrounds and measuring instrument reproducibility on esthetic aspects of maxillary implant-supported single crown. Clin. Oral Impl. Res. 26, 2015, 250–256 doi: 10.1111/clr.12532
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Dental Implant treatment is considered an optimal treatment for the replacement of a single missing tooth. Although the survival and success rate of dental implants are often documented in studies, the standards of success for implant treatment are still not well defined. In 1989, Smith & Zarb suggested that success criteria should include adequate esthetic appearance such as the scalloped soft tissue lines with natural contours (Smith & Zarb 1989). Moreover, Belser et al. reviewed literature published from 1997 to 2003 and suggested an assessment of esthetic out-
comes should be included in clinical studies (Belser et al. 2004). An objective esthetic measurement tool is not only important to evaluate patient appearance improvement brought by implants, it is also believed it will benefit the profession for education and training purpose (Lang & Zitzmann 2012) or as a research tool to compare various surgical or prosthetic procedures (Meijer et al. 2005). In recent years, various esthetic evaluation systems have been introduced to evaluate implant-supported prosthesis and the surrounding
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Vaidya et al Assessing aesthetic outcomes of single implant crowns
mucosa which form more objective tools in daily practice. Nevertheless, it is believed that esthetic evaluation is to a great extent dependent on the subjective impression of the examiners. Furthermore, examiners specialization has been shown to affect esthetic evaluation on natural teeth (Kokich et al. 1999). Fu¨rhauser et al. (2005). F€ urhauser et al. proposed the Pink Esthetic Score (PES) for evaluating the soft tissues around single-implant crowns. In that study, 20 observers (Five prosthodontists, five oral surgeons, five orthodontists, and five dental students) evaluated 30 photographs of single-implant crowns twice in a 4-week interval. Consequently, orthodontists gave the lowest (most critical) ratings. According to the author, orthodontists who were not involved in implant therapy were less biased when assessing the tissues than professionals being involved in implant therapy. Reproducibility of the PES and the effects of the observer’s specialization were further investigated in Gehrke et al. (2008) study. Three general practitioners, three oral surgeons, three orthodontists, three implant master students, and three lay persons evaluated 30 photographs twice in 4 weeks. A high agreement (70.5%) was found between the two ratings in all occupational groups. Orthodontists had the best intraexaminer agreement (73.5%), but poorest (most critical) rating, while lay people had the least agreement (65.9%), but highest (least critical) rating. Belser et al. (2004) later introduced Pink Esthetic Score/White Esthetic Score (PES/WES) to evaluate implant crown and mucosa esthetics. Then, Cho et al. (2010) determined the effect of observers’ specialization using this index. A group of eight examiners (Two periodontists, two prosthodontists, two orthodontists, and two senior dental students) evaluated casts and photographs of 41 patients. The study founded that orthodontists gave more critical rating than other groups. Periodontists gave the most generous rating. But the statistical significance was only found in WES. Meijer et al. (2005) introduced the Implant Crown Aesthetic Index (ICAI) in 2005. In this pilot study, each observer (Two oral surgeons and two prosthodontists) evaluated 24 slides of single-implant-supported crowns twice. It was found that intra-observer agreement of prosthodontists (0.7) was better than that of oral surgeons (0.49 and 0.56) and considered to have higher reliability (0.61, good agreement). It was suggested that prosthodontists, being the one responsible for rehabilitation, were more experienced and thus gave more consistent scores. The author thus concluded
that ICAI is an objective tool for evaluation of implant crown and mucosa esthetics. But, Gehrke et al. again reviewed the ICAI in 2009. In that study, 10 examiners (Two general practitioners, two prosthodontists, two oral surgeons, two orthodontists, and two dental technicians) evaluated 23 photographs twice within 4 weeks. Intra-observer and interobserver agreements among the occupational groups were low to moderate. None of the groups showed any statistically superior validity or reliability Vihjalmsson et al. (2010) modified ICAI by using 3 points scalre system rather than 5 point scale. The modified ICAI was found to best combine the professional and lay people’s assessment. Up to now, in assessing esthetic outcomes, most investigators have demonstrated an effect of the dental specialization by focusing on one single esthetic index. No studies elaborated the effect of specialization when the examiners used two indices to assess the same images and it still remains unclear whether outcomes and correlation with specialization will remain consistent, when two different assessment systems are used. Apart from that, only one study recruited periodontists (Cho et al. 2010). Thus, the aim of this study was to investigate the effects of professional specialization as well as the validity and reproducibility of measuring instruments on esthetic outcomes assessment of singleimplant-supported crown in the esthetic region using two index systems with simple 3-graded rating. Both the Pink Esthetic Score and White Esthetic Score (PES/WES) and the modified Implant Crown Aesthetic Index (mod-ICAI) were to be applied.
grossly restored adjacent or contralateral teeth were excluded from the study. The photographs were all color printed and magnified to fit in half of an A4 size paper. A mark was applied to indicate the esthetics of the implant-supported restorations. Examiners
The study was carried out in two parts. In the first part, two postgraduate (Master of Dental Surgery, MDS) students in Implant Dentistry assessed the entire set of 20 photographs twice with PES/WES, with 1-week interval. After 1 month, the procedure was repeated using the mod-ICAI. In total, each examiner evaluated the photographs for four times, twice with each index. To reduce the bias, the photographs were reorganized in different order to minimize the effects of memorization. In the second part of the study, a total of 12 examiners from different dental health backgrounds were involved: two periodontists, two prosthodontists, two orthodontists, two oral surgeons, two dental technicians, two dental assistances (DAs). The criteria for evaluation were explained, and the same set of 20 photographs together with five photographs of unrestored dentition were assessed. This was to increase the variety of cases. For the six specialty groups (12 examiners), the first assessment was carried out with the PES/WES, the second one with modified ICAI after an interval of 1 week with rearranged order. The examiners were given the photographs, scoring forms, and a letter that briefly explained the methods of scoring, while they were allowed to read and raise questions regarding the terms used for the scoring parameters before starting. However, calibration between individuals was not carried out.
Material and methods Study material
Archive intra-oral photographs from patients of Prince Philip Dental Hospital, Hong Kong, and the archive of the Clinic of Periodontology and Fixed Prosthodontics, University of Berne, Switzerland, were used. Details about the capture settings of the photographs were not available. A total of 20 intraoral photographs of subjects with single-implant-supported crowns in the area of esthetic priority (central incisors, lateral incisors, canine, and 1st premolars of maxilla and mandible) with the presence of unrestored contralateral (for incisors to canines) or adjacent teeth (for premolars) were included. Photographs with (i) implant-supported bridges, (ii) single-implant restorations with the cantilever pontics, and (iii) lack of reference teeth, that is missing or
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Indices Pink Esthetic Score (PES) and White Esthetic Score (WES)
PES/WES were introduced by Belser et al. (2009). The PES contains five variables for evaluation: (i) mesial papilla, (ii) distal papilla, (iii) level of facial mucosa, (iv) curvature of facial mucosa, and (v) root convexity, soft tissue color, and texture. The WES also encompasses five variables: (i) general tooth form, (ii) tooth volume/outline, (iii) color-hue/value, (iv) surface texture, and (v) translucency. A three-point score of 2-1-0 is assigned to each parameter according to the amount of discrepancy compared with the natural reference tooth. 2-1-0 stands for no discrepancy, mild discrepancy, major discrepancy,
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respectively. For mesial and distal papillae, 21-0 represents complete presence, incomplete presence, and absence of the papilla. Modified implant crown aesthetic index (modICAI)
The original ICAI includes nine items developed by Meijer et al. (2005) using a five-point scale. This index was modified by Vilhjalmsson et al. (2010) into a three-point scale system to reduce the problem of interpretation associated with more intermediate categories. Mod-ICAI is categorized into two parts: the ICAI mucosa and the ICAI crown The ICAI mucosa includes four items: (i) the position of mucosa in approximal embrasures (height of papilla), (ii) the position of labial surface of peri-implant mucosa, (iii) the contour of labial surface of mucosa, (iv) the color (redness) and (v) the surface characteristics of labial mucosa (e.g., presence of attached gingiva). The ICAI crown encompasses five items: (i) mesio-distal dimension of the crown, (ii) position of incisal edge, (iii) labial convexity of crown, (iv) color and translucency of crown, and (v) surface of crown (roughness, textures). 2-1-0 means no deviation, slight deviation, and gross deviation, respectively, in this study. For the position of the approximal and labial mucosae, gross deviation means a deviation ≥ 1.5 mm. Slight deviation means a deviation < 1.5 mm. The maximum total score for the mod-ICAI is 18. All the indices compare the implant-supported crown to adjacent and/or contralateral teeth. Statistics
The statistical analysis was performed using SPSS 19 program. Cohen Kappa (j) was calculated for intra-examiner agreement in two MDS students. Kruskal–Wallis test was used to estimate the difference among all the six specialties. Mann–Whitney U-test was then applied for pairwise comparisons of the rating difference between two specialties using the PES/WES or modified ICAI. A total of 15 pairwise comparisons were available for six
specialties. An adjusted significance level of P = 0.05/15 = 0.003 was used to reduce type I error (Bonferroni correction). Interobservers’ agreement was calculated for total and subscore of each index within specialty. To be practical, a difference of 1 was considered to be acceptable for the parts of subscore, while a difference of 2 was considered to be acceptable for total score.
Results Descriptive statistics for 6 specialties
A general overview of the implant esthetic scores is presented in Table 1. Among the 20 photographs, the PEW/WES had a wide range of ratings from 6 to 19.5 with a mean score of 14.42, while modified ICAI had scores ranged from 5 to 18 and a mean score of 13.46. This showed that some of implant esthetics have achieved very high scores while some were considered poor. For the PES/WES, DAs had the highest mean (16.92). Prosthodontists had the lowest mean (12.22). The standard deviations were lowest (1.99) for DA and highest (3.44) for orthodontists. For the modified ICAI, periodontists gave the highest mean score (15.56). The lowest mean (11.98) was obtained by orthodontists. Standard deviations were lowest with periodontists (1.93), and highest (3.42) with oral surgeons. For the soft tissue esthetics in PES, DAs yielded the highest mean (8.38), while prosthodontists had the lowest mean (5.82) score. DAs had the lowest standard deviations (0.93), while technicians had the highest standard deviations (2.18). For the ICAImucosa scores, periodontists had highest mean values (6.46) and the lowest standard deviations (1.04), while orthodontists had lowest mean values (4.86). Oral surgeons had the highest standard deviations of 2.02. Regarding the implant crown esthetic evaluation, DAs had highest mean score for the WES (8.74), while their mean score was less than that of the periodontists (9.10) in ICAI crown. The lowest WES mean score was given by prosthodontists (6.40), while, the
lowest mean score in ICAI crown was given by orthodontists (7.12). For the WES, standard deviations ranged from 0.94 (DAs) to 2.01 (orthodontists). However, the range in ICAI crown was from 1.10 (periodontists) to 1.84 (oral surgeons). Comparison between the six specialties
Scores by all six specialties were compared by means of Kruskal–Wallis test, and the result was highly significant (P ≤ 0.001) for each index system, this remaining true for subscores (PES, WES, ICAI crown, ICAI mucosa). Pairwise comparisons of the six specialties
When the specialties were compared in pairs with the Mann–Whitney U-test (Table 2), of 15 pairs of comparison, nine pairs demonstrated significant differences in the total scores or subscore rating with P value ≤ 0.003. For example, the differences between orthodontists and periodontists in ICAI (P ≤ 0.001), ICAI mucosa (P = 0.003) and ICAI crown (P ≤ 0.001) are significant. These nine pairs were then reviewed for their mean rank values to find out which group gave higher scores. Intra-examiner agreement for 2 MDS students
Table 3 summarizes the PES/WES individual parameter intra-examiner agreement. The Kappa value showed that all the individual parameters except for the crown surface texture and translucency showed fair-to-very good intra-examiner agreements (j = 0.30– 0.89) for both the examiners. Both the examiners had poor intra-examiner agreement for crown translucency (0.12 and 0.20, respectively). The second examiner also had crown surface texture as poor intra-examiner agreement (j = 0.00). Table 4 summarizes the modified-ICAI individual parameter intra-examiner agreement. The Kappa value showed that all individual parameters had fair-to-very good intra-examiner agreements for examiner 1 (j = 0.39–1.00). For examiner 2, all individual parameters, except the mesiodistal dimension
Table 1. Descriptive statistics of PES/WES vs. mod-ICAI Mean(SD)/Median
Ortho
PES/WES Mod-ICAI PES Mod-ICAI Mucosa WES Mod-ICAI Crown
13.62 11.98 6.40 4.86 7.22 7.12
Pros (3.44)/13.50 (3.25)/11.00 (2.11)/6.00 (1.90)/5.00 (2.01)/7.50 (1.76)/7.00
12.22 12.06 5.82 4.90 6.40 7.16
OS (2.38)/13.00 (2.62)/12.50 (1.64)/6.00 (1.80)/5.50 (1.31)/6.50 (1.30)/7.00
14.54 12.82 6.48 5.10 8.04 7.72
Perio (3.00)/15.00 (3.42)/14.00 (1.75)/7.00 (2.02)/5.50 (1.75)/8.50 (1.84)/8.00
15.62 15.56 7.14 6.46 8.48 9.10
Tech (3.08)/17.00 (1.93)/16.00 (1.76)/7.50 (1.04)/6.50 (1.65)/9.00 (1.10)/9.50
13.64 13.18 6.18 5.26 7.46 8.12
DA (3.15)/13.50 (2.36)/13.50 (2.18)/6.00 (1.51)/5.50 (1.64)/7.50 (1.45)/8.50
16.92 15.16 8.38 6.44 8.74 8.72
(1.99)/17.5 (2.02)/16.00 (0.93)/8.50 (1.10)/6.50 (0.94)/9.00 (1.15)/9.00
Sample size n = 25 for PES/WES, mod-ICAI and their subgroups.
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© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Vaidya et al Assessing aesthetic outcomes of single implant crowns
Table 2. The pairwise comparison results of specialties by Mann–Whitney U-test Index
Groups Perio > Pros (P < 0.001)
PW
OS > pros (P = 0.001)
DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P < 0.001) DA > Ortho (P < 0.001), Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P < 0.001), Tech (P < 0.001) DA > Ortho (P = 0.002), Pros (P = 0.001) DA > Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001)
Perio > Ortho (P < 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P = 0.001)
Mod-ICAI Pes
Perio > Ortho (P = 0.003), Pros (P = 0.001), Perio > Pros (P < 0.001) Perio > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.002)
ICAI mucosa Wes ICAI crown
OS > Pros (P < 0.001)
Table 3. PES/WES individual parameter intra-examiner agreement summary
Parameters Mesial papilla Distal papilla Level of facial mucosa Curvature of facial mucosa Root convexity Tooth form Tooth volume Tooth color Surface texture Translucency
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
Intra-observer agreement % Examiner Y
0.84 0.69 0.64
Very good Good Good
90 80 80
0.76 0.68 0.30
Good Good Fair
85 80 55
0.89
Very good
95
0.48
Moderate
80
0.60 0.42 0.50 0.51 0.50 0.12
Moderate Moderate Moderate Moderate Moderate Poor
80 70 75 75 85 60
0.69 0.58 0.73 0.77 0.00 0.20
Good Moderate Good Good Poor Poor
85 85 85 95 95 65
Table 4. Modified-ICAI individual parameter intra-examiner agreement summary
Parameters Height of papilla Position of labial surface Contour of labial surface Color of labial mucosal surface Mesiodistal dimension of crown Position incisal of edge Labial convexity of crown Color and translucency of crown Surface of crown
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
0.63 0.62
Good Good
0.60
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
80 75
0.21 0.67
Fair Good
55 80
Moderate
80
0.48
Moderate
80
0.39
Fair
70
0.60
Moderate
80
1
Very good
100
0.00
Poor
95
0.64
Good
80
0.88
Very good
95
0.49
Moderate
75
0.71
Good
85
0.70
Good
85
0.52
Moderate
80
0.62
Good
85
1
Very good
100
of the crown (j = 0.00), had fair-to-very good intra-examiner agreement as well (j = 0.21– 1.00).
Interobservers’ agreement within each specialty
Interobservers’ agreement was calculated within each specialty (Figures 1–3). To be practical, a difference of 1 was considered acceptable for subscore values, while a difference of 2 was considered acceptable for total score values. Agreement of prosthodontists ranged from 4% (PES/WES) to 28% (ICAI), and subscores of the two indices were 12–
28% (PES/ICAI mucosa), 8–32% (WES/ICAI crown), respectively. Oral surgeons had 24% agreement in PES/WES, 32% in PES for mucosa esthetics, and 24% in WES for prosthesis assessment. DAs displayed low agreement in PES (20%) and WES (28%). Others achieved a moderate level of agreement ranged from 48% to 80% with the mentioned allowance. Overall, the PES assessment shows lower agreement compared with other indices. From Figures 1–3, it was founded that the agreement was in general lower with PES/WES than mod-ICAI with a few exceptions.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Intra-observer agreement % Examiner Y
Discussion The favorable esthetic outcomes of the soft tissue after placement of implants apparently depend on various factors, such as the morphology of the site, the implant size, and the three-dimensional position of the implant (Buser et al. 2004; Kourkouta et al. 2009). The present study has demonstrated that esthetic outcomes may be objectively assessed using appropriate index systems. Even so, the effect of an assessor’s subjective impression and degree of specialization were considered to be an issue to affect the
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Vaidya et al Assessing aesthetic outcomes of single implant crowns
Table 2. The pairwise comparison results of specialties by Mann–Whitney U-test Index
Groups Perio > Pros (P < 0.001)
PW
OS > pros (P = 0.001)
DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P < 0.001) DA > Ortho (P < 0.001), Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P < 0.001), Tech (P < 0.001) DA > Ortho (P = 0.002), Pros (P = 0.001) DA > Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001)
Perio > Ortho (P < 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P = 0.001)
Mod-ICAI Pes
Perio > Ortho (P = 0.003), Pros (P = 0.001), Perio > Pros (P < 0.001) Perio > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.002)
ICAI mucosa Wes ICAI crown
OS > Pros (P < 0.001)
Table 3. PES/WES individual parameter intra-examiner agreement summary
Parameters Mesial papilla Distal papilla Level of facial mucosa Curvature of facial mucosa Root convexity Tooth form Tooth volume Tooth color Surface texture Translucency
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
Intra-observer agreement % Examiner Y
0.84 0.69 0.64
Very good Good Good
90 80 80
0.76 0.68 0.30
Good Good Fair
85 80 55
0.89
Very good
95
0.48
Moderate
80
0.60 0.42 0.50 0.51 0.50 0.12
Moderate Moderate Moderate Moderate Moderate Poor
80 70 75 75 85 60
0.69 0.58 0.73 0.77 0.00 0.20
Good Moderate Good Good Poor Poor
85 85 85 95 95 65
Table 4. Modified-ICAI individual parameter intra-examiner agreement summary
Parameters Height of papilla Position of labial surface Contour of labial surface Color of labial mucosal surface Mesiodistal dimension of crown Position incisal of edge Labial convexity of crown Color and translucency of crown Surface of crown
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
0.63 0.62
Good Good
0.60
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
80 75
0.21 0.67
Fair Good
55 80
Moderate
80
0.48
Moderate
80
0.39
Fair
70
0.60
Moderate
80
1
Very good
100
0.00
Poor
95
0.64
Good
80
0.88
Very good
95
0.49
Moderate
75
0.71
Good
85
0.70
Good
85
0.52
Moderate
80
0.62
Good
85
1
Very good
100
of the crown (j = 0.00), had fair-to-very good intra-examiner agreement as well (j = 0.21– 1.00).
Interobservers’ agreement within each specialty
Interobservers’ agreement was calculated within each specialty (Figures 1–3). To be practical, a difference of 1 was considered acceptable for subscore values, while a difference of 2 was considered acceptable for total score values. Agreement of prosthodontists ranged from 4% (PES/WES) to 28% (ICAI), and subscores of the two indices were 12–
28% (PES/ICAI mucosa), 8–32% (WES/ICAI crown), respectively. Oral surgeons had 24% agreement in PES/WES, 32% in PES for mucosa esthetics, and 24% in WES for prosthesis assessment. DAs displayed low agreement in PES (20%) and WES (28%). Others achieved a moderate level of agreement ranged from 48% to 80% with the mentioned allowance. Overall, the PES assessment shows lower agreement compared with other indices. From Figures 1–3, it was founded that the agreement was in general lower with PES/WES than mod-ICAI with a few exceptions.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Intra-observer agreement % Examiner Y
Discussion The favorable esthetic outcomes of the soft tissue after placement of implants apparently depend on various factors, such as the morphology of the site, the implant size, and the three-dimensional position of the implant (Buser et al. 2004; Kourkouta et al. 2009). The present study has demonstrated that esthetic outcomes may be objectively assessed using appropriate index systems. Even so, the effect of an assessor’s subjective impression and degree of specialization were considered to be an issue to affect the
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They are also more closely to lay men in terms of their dental knowledge and perception among the dental specialties. In this respect, the results of the present study corroborate those of a study (Kokich et al. 1999), in which lay people were less discerning of tooth esthetic discrepancy than dental professionals. Similar results were reported for patients giving higher rates on implant crown esthetic outcomes than prosthodontists (Chang et al. 1999; Meijndert et al. 2007). In general, the opinions of the patients tended to be more positive than the opinion of professionals when applying PES/WES or ICAI (Meijndent et al. 2007; Belser et al. 2009). In another study, periodontists gave the highest mean PES/WES scores (Cho et al. 2010). They were followed by dental students, the prosthodontists, and the orthodontists. But the differences between these groups were not statistically significant except for WES. Similarly, periodontists gave higher ratings as well compared to the rest of the dental professionals (excluding the DAs) in our results. Periodontists, therefore, appear to be more generous in their assessment of the esthetics of implant-supported crowns. On the other hand, they may also accept mucosal esthetics more readily in healed periodontal situations. This professional background influence was more obvious with the modified ICAI mucosa. In the first study on PES presented by F€ urhauser et al. (2005), the orthodontists were found to be the most critical professionals, having lower ratings than the prosthodontists, the oral surgeons, and the dental students. Obviously, orthodontists are trained to focus on natural esthetics, and hence, may be considered less biased by almost not being involved in implant treatment. Moreover, this was confirmed in
another study (Gehrke et al. 2008), in which orthodontists, again, yielded the poorest ratings among general practitioners, oral surgeons, implant MDS students, and lay people. When evaluating the ICAI, however, orthodontists gave the best rating, while the dental laboratory technicians were poorest (Gehrke et al. 2009). The results of our study differ from those mentioned in the sense that the lowest ratings according to mean rank values were given by prosthodontists, followed by orthodontists regardless of the index used (including the subscores). This sounds more rational because prosthodontists are trained to assess the esthetic of dental prosthesis while orthodontists focused on natural dentition. In applying PES, mesial and distal papillae are considered two parameters to be evaluated and need to be identified for their absence, incomplete, or complete presence. Sometimes, it was difficult to evaluate the completeness of a distal papilla from a frontal view photograph as discussed previously (Hosseini & Godfredsen et al. 2012). Furthermore, a situation with perfectly healthy tissues may not score with the deserved points if papillae are missing due to recession. The value and the relevance of the PES for assessing implant-supported prostheses in patients with a history of treated periodontitis may, therefore, be questioned. Similarly, by applying the ICAI mucosa, ratings for the papilla require the comparison to a contralateral area. Consequently, less variation should come out when a more general form of recession is considered. The last item of PES consists of three independent parameters (root convexity/soft tissue color/texture), which could also be a source that brought in more disagreement among assessors. For the WES, tooth form and tooth volume were parameters difficult to be identified on two-dimen-
sional photographs in the present study. For ICAI crown, parameters such as the mesiodistal dimension of the crown and the position of incisal edge were used. These were easier to be identified from photographs, and thus, resulted in a higher agreement of rating between the individual assessors. The present study had some limitations in the design. If similar study is to be conducted in the future, calibration of the assessors might be beneficial to reduce the risk of bias (Meijer et al. 2004). It is also advised to recruit more examiners in each specialty to reduce effect of the subjective individual bias. The demographic background of the examiners such as their gender, age, and practice experience might also play a role in their assessment. The importance of these factors should be evaluated and may be controlled. Study casts or computer-assisted measurement could be provided in addition to clinical photographs to facilitate the assessment of crown outline, volume, texture, root convexity, papilla, and soft tissue texture (Belser et al. 2004; Weinl€ander et al. 2009).
Conclusions In conclusion, these two indices (PES/WES and mod-ICAI) may be reliable in evaluating implant esthetics. However, bias from subjective perception of esthetic aspects cannot be overlooked. The assessor’s degree of specialization affected the results with both indices. DAs and periodontists were identified to provide more favorable ratings than other specialties. Prosthodontists were the most critical professionals in this study. When using modified ICAI, higher interexaminer agreement was achieved than with PES/WES scores.
References Belser, U.C., Gr€ utter, L., Vailati, F., Bornstein, M.M., Weber, H.P. & Buser, D. (2009) Outcome evaluation of early placed maxillary anterior single-tooth implants using objective esthetic criteria: a cross-sectional, retrospective study in 45 patients with a 2- to 4-year follow up using pink and white esthetic scores. Journal of Periodontology 80: 140–151. Belser, U.C., Schmid, B., Higginbottom, F. & Buser, D. (2004) Outcome analysis of implant restorations located in the anterior maxilla: a review of the recent literature. International Journal of Oral and Maxillofacial Implants 19: 30–42.
Buser, D., Martin, W., Belser, U.C. (2004) Optimizing esthetics for implant restorations in the anterior maxilla: anatomic and surgical considerations. International Journal of Oral and Maxillofacial Implants 19: Suppl. 43–61. Chang, M., Wennstr€ om, J.L., Odman, P. & Andersson, B. (1999) Implant supported single-tooth replacements compared to contralateral natural teeth. Crown and soft tissue dimensions. Clinical Oral Implants Research 10: 185–194. Cho, H.L., Lee, J.K., Um, H.S. & Chang, B.S. (2010) Esthetic evaluation of maxillary single-tooth implants in the esthetic zone. Journal of Periodontal and Implant Science 40: 188–193.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
F€ urhauser, R., Florescu, D., Benesch, T., Haas, R., Mailath, G. & Watzek, G. (2005) Evaluation of soft tissue around single-tooth implant crowns: the pink esthetic score. Clinical Oral Implants Research 16: 639–644. Gehrke, P., Degidi, M., Lulay-Saad, Z. & Dhom, G. (2009) Reproducibility of the implant crown aesthetic index-rating aesthetics of single-implant crowns and adjacent soft tissues with regard to observer dental specialization. Clinical Implant Dentistry and Related Research 11: 201– 213. Gehrke, P., Lobert, M. & Dhom, G. (2008) Reproducibility of the pink esthetic score—rating soft
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tissue esthetics around single implant restorations with regard to dental observer specialization. Journal of Esthetic and Restorative Dentistry 20: 375–384. Hosseini, M. & Gotfredsen, K. (2012) A feasible, aesthetic quality evaluation of implant- supported single crowns: an analysis of validity and reliability. Clinical Oral Implants Research 23: 453–458. Kokich, V.O., Jr, Kiyak, H.A. & Shapiro, P.A. (1999) Comparing the perception of dentists and lay people to altered dental esthetics. Journal of Esthetic Dentistry 11: 311–324. Kourkouta, S., Dedi, K.D., Paquette, D.W. & Mol, A. (2009) Interproximal tissue dimensions in relation to adjacent implants in the anterior maxilla: clinical observations and patient aesthetic evaluation. Clinical Oral Implants Research 20: 1375–1385.
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Lang, N.P. & Zitzmann, N.U. and on behalf of Working Group 3 of the VIII European Workshop on Periodontology. (2012) Clinical research in implant dentistry: evaluation of implant-supported restorations, aesthetic and patient-reported outcomes. Journal of Clinical Periodontology 39 (Suppl. 12): 133–138 Meijer, H.J., Stellingsma, K., Meijndenrt, L. & Raghoebar, G.M. (2005) A new index for rating aesthetics of implant-supported single crowns and adjacent soft tissues – the Implant Crown Aesthetic Index. Clinical Oral Implants Research 16: 645–649. Meijndert, L., Meijer, H.J., Stellingsma, K., Stegenga, B. & Raghoebar, G.M. (2007) Evaluation of aesthetics of implant-supported single-tooth replacements using different bone augmentation procedures: a prospective randomized clinical
study. Clinical Oral Implants Research 18: 715–719. Smith, D.E. & Zarb, G.A. (1989) Criteria for success of osseointegrated endosseous implants. Journal of Prosthetic Dentistry 62: 567–572. Vilhjalmsson, V.H., Klock, K.S., Størksen, K. & B ardsen, A. (2011) Aesthetics of implant supported single anterior maxillary crowns evaluated by objective indices and participants’ perceptions. Clinical Oral Implants Research 22: 1399–1403. Weinl€ander, M., Lekovic, V., Spadijer Gostovic, S., Milicic, B., Krennmair, G. & Plenk, H. Jr (2009) Gingivomorphometry–esthetic evaluation of the crown–mucogingival complex: a new method for collection and measurement of standardized and reproducible data in oral photography. Clinical Oral Implants Research 20: 526–530.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Evaluation of the influence exerted by different dental specialty backgrounds and measuring instrument reproducibility on esthetic aspects of maxillary implant-supported single crown
Authors’ affiliations: Samriddhi Vaidya, Yu Lau Elaine Ho, Jie Hao, Niklaus P. Lang, Nikos Mattheos, Implant Dentistry, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR Niklaus P. Lang, Faculty of Dentistry, University of Zurich, Zurich, Switzerland Niklaus P. Lang, Faculty of Dentistry, University of Bern, Bern, Switzerland
Key words: esthetics, implant restoration, modified implant crown aesthetic index, pink
Corresponding author: Nikos Mattheos, DDS, MAS(Perio), PhD Oral Rehabilitation, Faculty of Dentistry The University of Hong Kong 34 Hospital Road, Sai Ying Pun Hong Kong, Hong Kong SAR Tel.: + 852 28590310 Fax: + 852 2858 6114 e-mail: [email protected]
maxillary implants supported single-tooth prosthesis.
esthetic score/white esthetic score Abstract Objective: To evaluate the influence exerted by different dental specialty backgrounds as well as the validity and reproducibility of the Pink Esthetic Score/White Esthetic Score (PES/WES) and the modified Implant Crown Aesthetic Index (mod-ICAI) on the assessment of esthetic aspects of Material and methods: A total of fourteen examiners (Two orthodontists, two prosthodontists, two oral surgeons, two periodontists, two dental technicians, two dental assistants, and two postgraduate students in Implant Dentistry evaluated 20 photographs of single-implant-supported crowns and five photographs of unrestored teeth of esthetic zone in a two part study. The examiners assessed the photographs with each index (Pink Esthetic Score/White Esthetic Score and modified Implant Crown Aesthetic Index), twice with a week’s interval. Orders of photographs were rearranged in the second assessment. Results: Kruskal–Wallis test results showed significant differences among all the six specialties (P ≤ 0.001). DAs and periodontists had significantly better ratings than other specialties with both indices. Prosthodontists had the lowest mean rank scores regardless of the index. Interobserver agreement was also lowest between the two prosthodontists (4–28%), rest of the groups had lowto-moderate agreement (20–80%) when limited allowance was accepted. With mod-ICAI, more interobserver agreement was noted within the specialty group than with PES/WES. Conclusions: The PES/WES and the modified ICAI can be reliable estimates of esthetic outcomes. The assessor degree of specialization affected the esthetic evaluation with both the PES/WES and the modified ICAI. DAs and periodontists were identified to provide more favorable ratings than other specialties while prosthodontists were most critical in this study. With modified ICAI, more interobserver agreement within specialty resulted. The interexaminer agreement may be increased if more tolerance of 1–2 points is considered.
Date: Accepted 29 October 2014 To cite this article: Vaidya S, Ho YLE, Hao J, Lang NP, Mattheos N. Evaluation of the influence exerted by different dental specialty backgrounds and measuring instrument reproducibility on esthetic aspects of maxillary implant-supported single crown. Clin. Oral Impl. Res. 26, 2015, 250–256 doi: 10.1111/clr.12532
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Dental Implant treatment is considered an optimal treatment for the replacement of a single missing tooth. Although the survival and success rate of dental implants are often documented in studies, the standards of success for implant treatment are still not well defined. In 1989, Smith & Zarb suggested that success criteria should include adequate esthetic appearance such as the scalloped soft tissue lines with natural contours (Smith & Zarb 1989). Moreover, Belser et al. reviewed literature published from 1997 to 2003 and suggested an assessment of esthetic out-
comes should be included in clinical studies (Belser et al. 2004). An objective esthetic measurement tool is not only important to evaluate patient appearance improvement brought by implants, it is also believed it will benefit the profession for education and training purpose (Lang & Zitzmann 2012) or as a research tool to compare various surgical or prosthetic procedures (Meijer et al. 2005). In recent years, various esthetic evaluation systems have been introduced to evaluate implant-supported prosthesis and the surrounding
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Vaidya et al Assessing aesthetic outcomes of single implant crowns
mucosa which form more objective tools in daily practice. Nevertheless, it is believed that esthetic evaluation is to a great extent dependent on the subjective impression of the examiners. Furthermore, examiners specialization has been shown to affect esthetic evaluation on natural teeth (Kokich et al. 1999). Fu¨rhauser et al. (2005). F€ urhauser et al. proposed the Pink Esthetic Score (PES) for evaluating the soft tissues around single-implant crowns. In that study, 20 observers (Five prosthodontists, five oral surgeons, five orthodontists, and five dental students) evaluated 30 photographs of single-implant crowns twice in a 4-week interval. Consequently, orthodontists gave the lowest (most critical) ratings. According to the author, orthodontists who were not involved in implant therapy were less biased when assessing the tissues than professionals being involved in implant therapy. Reproducibility of the PES and the effects of the observer’s specialization were further investigated in Gehrke et al. (2008) study. Three general practitioners, three oral surgeons, three orthodontists, three implant master students, and three lay persons evaluated 30 photographs twice in 4 weeks. A high agreement (70.5%) was found between the two ratings in all occupational groups. Orthodontists had the best intraexaminer agreement (73.5%), but poorest (most critical) rating, while lay people had the least agreement (65.9%), but highest (least critical) rating. Belser et al. (2004) later introduced Pink Esthetic Score/White Esthetic Score (PES/WES) to evaluate implant crown and mucosa esthetics. Then, Cho et al. (2010) determined the effect of observers’ specialization using this index. A group of eight examiners (Two periodontists, two prosthodontists, two orthodontists, and two senior dental students) evaluated casts and photographs of 41 patients. The study founded that orthodontists gave more critical rating than other groups. Periodontists gave the most generous rating. But the statistical significance was only found in WES. Meijer et al. (2005) introduced the Implant Crown Aesthetic Index (ICAI) in 2005. In this pilot study, each observer (Two oral surgeons and two prosthodontists) evaluated 24 slides of single-implant-supported crowns twice. It was found that intra-observer agreement of prosthodontists (0.7) was better than that of oral surgeons (0.49 and 0.56) and considered to have higher reliability (0.61, good agreement). It was suggested that prosthodontists, being the one responsible for rehabilitation, were more experienced and thus gave more consistent scores. The author thus concluded
that ICAI is an objective tool for evaluation of implant crown and mucosa esthetics. But, Gehrke et al. again reviewed the ICAI in 2009. In that study, 10 examiners (Two general practitioners, two prosthodontists, two oral surgeons, two orthodontists, and two dental technicians) evaluated 23 photographs twice within 4 weeks. Intra-observer and interobserver agreements among the occupational groups were low to moderate. None of the groups showed any statistically superior validity or reliability Vihjalmsson et al. (2010) modified ICAI by using 3 points scalre system rather than 5 point scale. The modified ICAI was found to best combine the professional and lay people’s assessment. Up to now, in assessing esthetic outcomes, most investigators have demonstrated an effect of the dental specialization by focusing on one single esthetic index. No studies elaborated the effect of specialization when the examiners used two indices to assess the same images and it still remains unclear whether outcomes and correlation with specialization will remain consistent, when two different assessment systems are used. Apart from that, only one study recruited periodontists (Cho et al. 2010). Thus, the aim of this study was to investigate the effects of professional specialization as well as the validity and reproducibility of measuring instruments on esthetic outcomes assessment of singleimplant-supported crown in the esthetic region using two index systems with simple 3-graded rating. Both the Pink Esthetic Score and White Esthetic Score (PES/WES) and the modified Implant Crown Aesthetic Index (mod-ICAI) were to be applied.
grossly restored adjacent or contralateral teeth were excluded from the study. The photographs were all color printed and magnified to fit in half of an A4 size paper. A mark was applied to indicate the esthetics of the implant-supported restorations. Examiners
The study was carried out in two parts. In the first part, two postgraduate (Master of Dental Surgery, MDS) students in Implant Dentistry assessed the entire set of 20 photographs twice with PES/WES, with 1-week interval. After 1 month, the procedure was repeated using the mod-ICAI. In total, each examiner evaluated the photographs for four times, twice with each index. To reduce the bias, the photographs were reorganized in different order to minimize the effects of memorization. In the second part of the study, a total of 12 examiners from different dental health backgrounds were involved: two periodontists, two prosthodontists, two orthodontists, two oral surgeons, two dental technicians, two dental assistances (DAs). The criteria for evaluation were explained, and the same set of 20 photographs together with five photographs of unrestored dentition were assessed. This was to increase the variety of cases. For the six specialty groups (12 examiners), the first assessment was carried out with the PES/WES, the second one with modified ICAI after an interval of 1 week with rearranged order. The examiners were given the photographs, scoring forms, and a letter that briefly explained the methods of scoring, while they were allowed to read and raise questions regarding the terms used for the scoring parameters before starting. However, calibration between individuals was not carried out.
Material and methods Study material
Archive intra-oral photographs from patients of Prince Philip Dental Hospital, Hong Kong, and the archive of the Clinic of Periodontology and Fixed Prosthodontics, University of Berne, Switzerland, were used. Details about the capture settings of the photographs were not available. A total of 20 intraoral photographs of subjects with single-implant-supported crowns in the area of esthetic priority (central incisors, lateral incisors, canine, and 1st premolars of maxilla and mandible) with the presence of unrestored contralateral (for incisors to canines) or adjacent teeth (for premolars) were included. Photographs with (i) implant-supported bridges, (ii) single-implant restorations with the cantilever pontics, and (iii) lack of reference teeth, that is missing or
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Indices Pink Esthetic Score (PES) and White Esthetic Score (WES)
PES/WES were introduced by Belser et al. (2009). The PES contains five variables for evaluation: (i) mesial papilla, (ii) distal papilla, (iii) level of facial mucosa, (iv) curvature of facial mucosa, and (v) root convexity, soft tissue color, and texture. The WES also encompasses five variables: (i) general tooth form, (ii) tooth volume/outline, (iii) color-hue/value, (iv) surface texture, and (v) translucency. A three-point score of 2-1-0 is assigned to each parameter according to the amount of discrepancy compared with the natural reference tooth. 2-1-0 stands for no discrepancy, mild discrepancy, major discrepancy,
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respectively. For mesial and distal papillae, 21-0 represents complete presence, incomplete presence, and absence of the papilla. Modified implant crown aesthetic index (modICAI)
The original ICAI includes nine items developed by Meijer et al. (2005) using a five-point scale. This index was modified by Vilhjalmsson et al. (2010) into a three-point scale system to reduce the problem of interpretation associated with more intermediate categories. Mod-ICAI is categorized into two parts: the ICAI mucosa and the ICAI crown The ICAI mucosa includes four items: (i) the position of mucosa in approximal embrasures (height of papilla), (ii) the position of labial surface of peri-implant mucosa, (iii) the contour of labial surface of mucosa, (iv) the color (redness) and (v) the surface characteristics of labial mucosa (e.g., presence of attached gingiva). The ICAI crown encompasses five items: (i) mesio-distal dimension of the crown, (ii) position of incisal edge, (iii) labial convexity of crown, (iv) color and translucency of crown, and (v) surface of crown (roughness, textures). 2-1-0 means no deviation, slight deviation, and gross deviation, respectively, in this study. For the position of the approximal and labial mucosae, gross deviation means a deviation ≥ 1.5 mm. Slight deviation means a deviation < 1.5 mm. The maximum total score for the mod-ICAI is 18. All the indices compare the implant-supported crown to adjacent and/or contralateral teeth. Statistics
The statistical analysis was performed using SPSS 19 program. Cohen Kappa (j) was calculated for intra-examiner agreement in two MDS students. Kruskal–Wallis test was used to estimate the difference among all the six specialties. Mann–Whitney U-test was then applied for pairwise comparisons of the rating difference between two specialties using the PES/WES or modified ICAI. A total of 15 pairwise comparisons were available for six
specialties. An adjusted significance level of P = 0.05/15 = 0.003 was used to reduce type I error (Bonferroni correction). Interobservers’ agreement was calculated for total and subscore of each index within specialty. To be practical, a difference of 1 was considered to be acceptable for the parts of subscore, while a difference of 2 was considered to be acceptable for total score.
Results Descriptive statistics for 6 specialties
A general overview of the implant esthetic scores is presented in Table 1. Among the 20 photographs, the PEW/WES had a wide range of ratings from 6 to 19.5 with a mean score of 14.42, while modified ICAI had scores ranged from 5 to 18 and a mean score of 13.46. This showed that some of implant esthetics have achieved very high scores while some were considered poor. For the PES/WES, DAs had the highest mean (16.92). Prosthodontists had the lowest mean (12.22). The standard deviations were lowest (1.99) for DA and highest (3.44) for orthodontists. For the modified ICAI, periodontists gave the highest mean score (15.56). The lowest mean (11.98) was obtained by orthodontists. Standard deviations were lowest with periodontists (1.93), and highest (3.42) with oral surgeons. For the soft tissue esthetics in PES, DAs yielded the highest mean (8.38), while prosthodontists had the lowest mean (5.82) score. DAs had the lowest standard deviations (0.93), while technicians had the highest standard deviations (2.18). For the ICAImucosa scores, periodontists had highest mean values (6.46) and the lowest standard deviations (1.04), while orthodontists had lowest mean values (4.86). Oral surgeons had the highest standard deviations of 2.02. Regarding the implant crown esthetic evaluation, DAs had highest mean score for the WES (8.74), while their mean score was less than that of the periodontists (9.10) in ICAI crown. The lowest WES mean score was given by prosthodontists (6.40), while, the
lowest mean score in ICAI crown was given by orthodontists (7.12). For the WES, standard deviations ranged from 0.94 (DAs) to 2.01 (orthodontists). However, the range in ICAI crown was from 1.10 (periodontists) to 1.84 (oral surgeons). Comparison between the six specialties
Scores by all six specialties were compared by means of Kruskal–Wallis test, and the result was highly significant (P ≤ 0.001) for each index system, this remaining true for subscores (PES, WES, ICAI crown, ICAI mucosa). Pairwise comparisons of the six specialties
When the specialties were compared in pairs with the Mann–Whitney U-test (Table 2), of 15 pairs of comparison, nine pairs demonstrated significant differences in the total scores or subscore rating with P value ≤ 0.003. For example, the differences between orthodontists and periodontists in ICAI (P ≤ 0.001), ICAI mucosa (P = 0.003) and ICAI crown (P ≤ 0.001) are significant. These nine pairs were then reviewed for their mean rank values to find out which group gave higher scores. Intra-examiner agreement for 2 MDS students
Table 3 summarizes the PES/WES individual parameter intra-examiner agreement. The Kappa value showed that all the individual parameters except for the crown surface texture and translucency showed fair-to-very good intra-examiner agreements (j = 0.30– 0.89) for both the examiners. Both the examiners had poor intra-examiner agreement for crown translucency (0.12 and 0.20, respectively). The second examiner also had crown surface texture as poor intra-examiner agreement (j = 0.00). Table 4 summarizes the modified-ICAI individual parameter intra-examiner agreement. The Kappa value showed that all individual parameters had fair-to-very good intra-examiner agreements for examiner 1 (j = 0.39–1.00). For examiner 2, all individual parameters, except the mesiodistal dimension
Table 1. Descriptive statistics of PES/WES vs. mod-ICAI Mean(SD)/Median
Ortho
PES/WES Mod-ICAI PES Mod-ICAI Mucosa WES Mod-ICAI Crown
13.62 11.98 6.40 4.86 7.22 7.12
Pros (3.44)/13.50 (3.25)/11.00 (2.11)/6.00 (1.90)/5.00 (2.01)/7.50 (1.76)/7.00
12.22 12.06 5.82 4.90 6.40 7.16
OS (2.38)/13.00 (2.62)/12.50 (1.64)/6.00 (1.80)/5.50 (1.31)/6.50 (1.30)/7.00
14.54 12.82 6.48 5.10 8.04 7.72
Perio (3.00)/15.00 (3.42)/14.00 (1.75)/7.00 (2.02)/5.50 (1.75)/8.50 (1.84)/8.00
15.62 15.56 7.14 6.46 8.48 9.10
Tech (3.08)/17.00 (1.93)/16.00 (1.76)/7.50 (1.04)/6.50 (1.65)/9.00 (1.10)/9.50
13.64 13.18 6.18 5.26 7.46 8.12
DA (3.15)/13.50 (2.36)/13.50 (2.18)/6.00 (1.51)/5.50 (1.64)/7.50 (1.45)/8.50
16.92 15.16 8.38 6.44 8.74 8.72
(1.99)/17.5 (2.02)/16.00 (0.93)/8.50 (1.10)/6.50 (0.94)/9.00 (1.15)/9.00
Sample size n = 25 for PES/WES, mod-ICAI and their subgroups.
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Vaidya et al Assessing aesthetic outcomes of single implant crowns
Table 2. The pairwise comparison results of specialties by Mann–Whitney U-test Index
Groups Perio > Pros (P < 0.001)
PW
OS > pros (P = 0.001)
DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P < 0.001) DA > Ortho (P < 0.001), Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P < 0.001), Tech (P < 0.001) DA > Ortho (P = 0.002), Pros (P = 0.001) DA > Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001)
Perio > Ortho (P < 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P = 0.001)
Mod-ICAI Pes
Perio > Ortho (P = 0.003), Pros (P = 0.001), Perio > Pros (P < 0.001) Perio > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.002)
ICAI mucosa Wes ICAI crown
OS > Pros (P < 0.001)
Table 3. PES/WES individual parameter intra-examiner agreement summary
Parameters Mesial papilla Distal papilla Level of facial mucosa Curvature of facial mucosa Root convexity Tooth form Tooth volume Tooth color Surface texture Translucency
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
Intra-observer agreement % Examiner Y
0.84 0.69 0.64
Very good Good Good
90 80 80
0.76 0.68 0.30
Good Good Fair
85 80 55
0.89
Very good
95
0.48
Moderate
80
0.60 0.42 0.50 0.51 0.50 0.12
Moderate Moderate Moderate Moderate Moderate Poor
80 70 75 75 85 60
0.69 0.58 0.73 0.77 0.00 0.20
Good Moderate Good Good Poor Poor
85 85 85 95 95 65
Table 4. Modified-ICAI individual parameter intra-examiner agreement summary
Parameters Height of papilla Position of labial surface Contour of labial surface Color of labial mucosal surface Mesiodistal dimension of crown Position incisal of edge Labial convexity of crown Color and translucency of crown Surface of crown
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
0.63 0.62
Good Good
0.60
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
80 75
0.21 0.67
Fair Good
55 80
Moderate
80
0.48
Moderate
80
0.39
Fair
70
0.60
Moderate
80
1
Very good
100
0.00
Poor
95
0.64
Good
80
0.88
Very good
95
0.49
Moderate
75
0.71
Good
85
0.70
Good
85
0.52
Moderate
80
0.62
Good
85
1
Very good
100
of the crown (j = 0.00), had fair-to-very good intra-examiner agreement as well (j = 0.21– 1.00).
Interobservers’ agreement within each specialty
Interobservers’ agreement was calculated within each specialty (Figures 1–3). To be practical, a difference of 1 was considered acceptable for subscore values, while a difference of 2 was considered acceptable for total score values. Agreement of prosthodontists ranged from 4% (PES/WES) to 28% (ICAI), and subscores of the two indices were 12–
28% (PES/ICAI mucosa), 8–32% (WES/ICAI crown), respectively. Oral surgeons had 24% agreement in PES/WES, 32% in PES for mucosa esthetics, and 24% in WES for prosthesis assessment. DAs displayed low agreement in PES (20%) and WES (28%). Others achieved a moderate level of agreement ranged from 48% to 80% with the mentioned allowance. Overall, the PES assessment shows lower agreement compared with other indices. From Figures 1–3, it was founded that the agreement was in general lower with PES/WES than mod-ICAI with a few exceptions.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Intra-observer agreement % Examiner Y
Discussion The favorable esthetic outcomes of the soft tissue after placement of implants apparently depend on various factors, such as the morphology of the site, the implant size, and the three-dimensional position of the implant (Buser et al. 2004; Kourkouta et al. 2009). The present study has demonstrated that esthetic outcomes may be objectively assessed using appropriate index systems. Even so, the effect of an assessor’s subjective impression and degree of specialization were considered to be an issue to affect the
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Table 2. The pairwise comparison results of specialties by Mann–Whitney U-test Index
Groups Perio > Pros (P < 0.001)
PW
OS > pros (P = 0.001)
DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P < 0.001) DA > Ortho (P < 0.001), Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001), OS (P < 0.001), Tech (P < 0.001) DA > Ortho (P = 0.002), Pros (P = 0.001) DA > Pros (P < 0.001), Tech (P = 0.003) DA > Ortho (P = 0.001), Pros (P < 0.001)
Perio > Ortho (P < 0.001), Pros (P < 0.001), OS (P = 0.001), Tech (P = 0.001)
Mod-ICAI Pes
Perio > Ortho (P = 0.003), Pros (P = 0.001), Perio > Pros (P < 0.001) Perio > Ortho (P = 0.001), Pros (P < 0.001), OS (P = 0.002)
ICAI mucosa Wes ICAI crown
OS > Pros (P < 0.001)
Table 3. PES/WES individual parameter intra-examiner agreement summary
Parameters Mesial papilla Distal papilla Level of facial mucosa Curvature of facial mucosa Root convexity Tooth form Tooth volume Tooth color Surface texture Translucency
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
Intra-observer agreement % Examiner Y
0.84 0.69 0.64
Very good Good Good
90 80 80
0.76 0.68 0.30
Good Good Fair
85 80 55
0.89
Very good
95
0.48
Moderate
80
0.60 0.42 0.50 0.51 0.50 0.12
Moderate Moderate Moderate Moderate Moderate Poor
80 70 75 75 85 60
0.69 0.58 0.73 0.77 0.00 0.20
Good Moderate Good Good Poor Poor
85 85 85 95 95 65
Table 4. Modified-ICAI individual parameter intra-examiner agreement summary
Parameters Height of papilla Position of labial surface Contour of labial surface Color of labial mucosal surface Mesiodistal dimension of crown Position incisal of edge Labial convexity of crown Color and translucency of crown Surface of crown
Kappa value for examiner X
Kappa intra-examiner agreement Examiner X
0.63 0.62
Good Good
0.60
Intra-observer agreement % Examiner X
Kappa value for Examiner Y
Kappa intra-examiner agreement Examiner Y
80 75
0.21 0.67
Fair Good
55 80
Moderate
80
0.48
Moderate
80
0.39
Fair
70
0.60
Moderate
80
1
Very good
100
0.00
Poor
95
0.64
Good
80
0.88
Very good
95
0.49
Moderate
75
0.71
Good
85
0.70
Good
85
0.52
Moderate
80
0.62
Good
85
1
Very good
100
of the crown (j = 0.00), had fair-to-very good intra-examiner agreement as well (j = 0.21– 1.00).
Interobservers’ agreement within each specialty
Interobservers’ agreement was calculated within each specialty (Figures 1–3). To be practical, a difference of 1 was considered acceptable for subscore values, while a difference of 2 was considered acceptable for total score values. Agreement of prosthodontists ranged from 4% (PES/WES) to 28% (ICAI), and subscores of the two indices were 12–
28% (PES/ICAI mucosa), 8–32% (WES/ICAI crown), respectively. Oral surgeons had 24% agreement in PES/WES, 32% in PES for mucosa esthetics, and 24% in WES for prosthesis assessment. DAs displayed low agreement in PES (20%) and WES (28%). Others achieved a moderate level of agreement ranged from 48% to 80% with the mentioned allowance. Overall, the PES assessment shows lower agreement compared with other indices. From Figures 1–3, it was founded that the agreement was in general lower with PES/WES than mod-ICAI with a few exceptions.
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Intra-observer agreement % Examiner Y
Discussion The favorable esthetic outcomes of the soft tissue after placement of implants apparently depend on various factors, such as the morphology of the site, the implant size, and the three-dimensional position of the implant (Buser et al. 2004; Kourkouta et al. 2009). The present study has demonstrated that esthetic outcomes may be objectively assessed using appropriate index systems. Even so, the effect of an assessor’s subjective impression and degree of specialization were considered to be an issue to affect the
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Vaidya et al Assessing aesthetic outcomes of single implant crowns
They are also more closely to lay men in terms of their dental knowledge and perception among the dental specialties. In this respect, the results of the present study corroborate those of a study (Kokich et al. 1999), in which lay people were less discerning of tooth esthetic discrepancy than dental professionals. Similar results were reported for patients giving higher rates on implant crown esthetic outcomes than prosthodontists (Chang et al. 1999; Meijndert et al. 2007). In general, the opinions of the patients tended to be more positive than the opinion of professionals when applying PES/WES or ICAI (Meijndent et al. 2007; Belser et al. 2009). In another study, periodontists gave the highest mean PES/WES scores (Cho et al. 2010). They were followed by dental students, the prosthodontists, and the orthodontists. But the differences between these groups were not statistically significant except for WES. Similarly, periodontists gave higher ratings as well compared to the rest of the dental professionals (excluding the DAs) in our results. Periodontists, therefore, appear to be more generous in their assessment of the esthetics of implant-supported crowns. On the other hand, they may also accept mucosal esthetics more readily in healed periodontal situations. This professional background influence was more obvious with the modified ICAI mucosa. In the first study on PES presented by F€ urhauser et al. (2005), the orthodontists were found to be the most critical professionals, having lower ratings than the prosthodontists, the oral surgeons, and the dental students. Obviously, orthodontists are trained to focus on natural esthetics, and hence, may be considered less biased by almost not being involved in implant treatment. Moreover, this was confirmed in
another study (Gehrke et al. 2008), in which orthodontists, again, yielded the poorest ratings among general practitioners, oral surgeons, implant MDS students, and lay people. When evaluating the ICAI, however, orthodontists gave the best rating, while the dental laboratory technicians were poorest (Gehrke et al. 2009). The results of our study differ from those mentioned in the sense that the lowest ratings according to mean rank values were given by prosthodontists, followed by orthodontists regardless of the index used (including the subscores). This sounds more rational because prosthodontists are trained to assess the esthetic of dental prosthesis while orthodontists focused on natural dentition. In applying PES, mesial and distal papillae are considered two parameters to be evaluated and need to be identified for their absence, incomplete, or complete presence. Sometimes, it was difficult to evaluate the completeness of a distal papilla from a frontal view photograph as discussed previously (Hosseini & Godfredsen et al. 2012). Furthermore, a situation with perfectly healthy tissues may not score with the deserved points if papillae are missing due to recession. The value and the relevance of the PES for assessing implant-supported prostheses in patients with a history of treated periodontitis may, therefore, be questioned. Similarly, by applying the ICAI mucosa, ratings for the papilla require the comparison to a contralateral area. Consequently, less variation should come out when a more general form of recession is considered. The last item of PES consists of three independent parameters (root convexity/soft tissue color/texture), which could also be a source that brought in more disagreement among assessors. For the WES, tooth form and tooth volume were parameters difficult to be identified on two-dimen-
sional photographs in the present study. For ICAI crown, parameters such as the mesiodistal dimension of the crown and the position of incisal edge were used. These were easier to be identified from photographs, and thus, resulted in a higher agreement of rating between the individual assessors. The present study had some limitations in the design. If similar study is to be conducted in the future, calibration of the assessors might be beneficial to reduce the risk of bias (Meijer et al. 2004). It is also advised to recruit more examiners in each specialty to reduce effect of the subjective individual bias. The demographic background of the examiners such as their gender, age, and practice experience might also play a role in their assessment. The importance of these factors should be evaluated and may be controlled. Study casts or computer-assisted measurement could be provided in addition to clinical photographs to facilitate the assessment of crown outline, volume, texture, root convexity, papilla, and soft tissue texture (Belser et al. 2004; Weinl€ander et al. 2009).
Conclusions In conclusion, these two indices (PES/WES and mod-ICAI) may be reliable in evaluating implant esthetics. However, bias from subjective perception of esthetic aspects cannot be overlooked. The assessor’s degree of specialization affected the results with both indices. DAs and periodontists were identified to provide more favorable ratings than other specialties. Prosthodontists were the most critical professionals in this study. When using modified ICAI, higher interexaminer agreement was achieved than with PES/WES scores.
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