Elham Emami Raphael F. de Souza Jacques Bernier Pierre Rompr e Jocelyne S. Feine
Patient perceptions of the mandibular three-implant overdenture: a practicebased study
Authors’ affiliations: Elham Emami, Department of Restorative Dentistry, Faculty of Dentistry, Universite de Montreal, Montreal, QC, Canada Department of Social and Preventive Medicine, School of Public Health, Universite de Montreal, Montreal, QC, Canada Raphael F. de Souza, Department of Dental Materials and Prosthodontics, Ribeir~ao Preto Dental School, University of S~ao Paulo, Ribeir~ao Preto, Brazil Jacques Bernier, Centre d’Implantologie Ste-Foy, Quebec City, QC, Canada Pierre Rompr e, D epartement de Stomatologie, Faculte de M edecine Dentaire, Universite de Montreal, Montreal, QC, Canada Jocelyne S. Feine, Oral Health and Society Research Unit, Faculty of Dentistry, McGill University, Montreal, QC, Canada Department of Epidemiology and Biostatistics and Department of Oncology, Faculty of Medicine, McGill University, Montreal, QC, Canada
Key words: implant, implant overdenture, oral health-related quality of life, patient
Corresponding author: Elham Emami, DDS, MSc, PhD Department of Restorative Dentistry, Faculty of Dentistry, Department of Social and Preventive Medicine, School of Public Health, Universite de Montreal, Pavillon Roger-Gaudry, local C-219, 2900 Edouard-Montpetit. H3T 1J4 Montreal, QC, Canada Tel.: +1514343 6053 Fax: +1 514343 2233. e-mail: [email protected]
significant improvements in all seven domains of the OHIP-20 from pre- to post-treatment (total
satisfaction Abstract Objectives: Although three-implant overdentures have often been used in clinical practice, there are few studies to support this approach. Therefore, this study aimed to determine the magnitude of change in ratings of oral health-related quality of life and to assess patients’ satisfaction ratings with mandibular three-implant overdentures. Materials and methods: This quasi-experimental study examined oral health-related quality of life and satisfaction with prosthesis in 135 edentate participants (mean age 61.6 7.9 years) who received mandibular three-implant overdentures from 2006 to 2009 in a private practice in Quebec, Canada. Data were collected from individual’s dental records and a follow-up survey. The Oral Health Impact Profile (OHIP-20) was used to assess oral health-related quality of life at baseline and at follow-up. Satisfaction with the mandibular prostheses and perception of rocking movements were measured by use of a denture satisfaction questionnaire at follow-up. Descriptive statistics, bivariate and multivariate statistical analyses were used to analyse the data. Results: Individuals who received mandibular three-implant overdentures had statistically OHIP change score
25.1 P < 0.001). Pre-treatment OHIP scores and rotational movement explained
58% of the variance in the OHIP’s change score (P ≤ 0.05). More than three quarters of the sample population (75.6%) were completely satisfied with their three-implant overdentures, and 81.5% reported having no rocking movement. General satisfaction with the prostheses was not influenced by gender, type of fixture, or type of attachment. Conclusions: The treatment of edentulism by three-implant overdentures has favourable patientbased outcomes, with negligible perceptions of rotational movement. However, further research is needed to compare the efficacy of this alternative to other treatment modalities, such as the two-implant overdenture.
Date: Accepted 19 January 2014 To cite this article: Emami E, de Souza RF, Bernier J, Rompr e P, Feine JS. Patient perceptions of the mandibular three-implant overdenture: a practice-based study. Clin. Oral Impl. Res. 00, 2014, 1–5 doi: 10.1111/clr.12351
Although conventional dentures have been shown to be somewhat effective in reducing the major functional impairments associated with edentulism, they have inadequate retention, resulting in looseness and discomfort (Awad et al. 2000, 2003a,b). During the past decade, clinical studies have highlighted the cost-effectiveness of mandibular overdentures retained by two implants as a treatment option for edentulous patients (Awad et al. 2000, 2003a,b). Two-implant overdentures offer greater retention than conventional dentures, thus improving well-being and oral health-related quality of life (OHRQoL) to levels within the expectations of the edentulous population (Awad et al. 2003a,b; Raghoebar et al. 2003; Emami et al. 2009; Jabbour et al. 2011).
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
The advantages of two-implant overdentures have led to two international consensuses on the management of edentulism, namely the McGill and York Consensuses. Both have resulted in statements recommending these as the minimal standard of care for edentulous patients (Feine et al. 2002; Thomason et al. 2009, 2012). The viability of stud attachments (Cune et al. 2010) and immediate loading (Buttel et al. 2012) for twoimplant retained prostheses further increases their accessibility, due to the potential reduction in treatment time and complexity. One limitation of two-implant overdentures, however, is the potential for anterior/ posterior rotation of the denture base around the attachments. This issue was raised by clinicians and investigated in clinical
1
Emami et al Mandibular three-implant overdenture
research. In the study by Kimoto et al. (2009), the participants reported a rocking movement of their overdentures retained by two implants with ball attachments. This rotational movement was correlated with decreased chewing ability that could compromise a patient’s satisfaction and OHRQoL. The concept of three implants to support a mandibular denture with separate stud attachments or splinted implants has been introduced since 1980s, and this modality of treatment has been widely used in the clinic (Hobo et al. 1989; Renouard & Rangert 1999) (Zarb et al. 2004; Misch 2008). Although adding an additional implant increases the cost of treatment, this increased cost is still less than the cost of more expensive treatment alternatives, such as fixed implant restorations or removable prostheses supported by four or more implants. The addition of a third implant in the symphyseal region could provide indirect retention for the denture and preclude rotational movement without resulting in higher strain on the denturebearing mucosa, abutments, implants, or ridge (Liu et al. 2013). High implant survival and success rates, healthy peri-implant tissues (Parel 1986; Engquist et al. 1988; Mericske-Stern 1990), and favourable periimplant rates of bone loss (Deporter et al. 2002) have been reported for mandibular three-implant overdentures. However, a literature search demonstrates that there is still little research regarding patient perceptions of three-implant overdentures (Geckili et al. 2011). Therefore, the aim of this study was to provide patient-reported data on the effectiveness of mandibular three-implant overdentures. More specifically, the chosen outcomes were OHRQoL, patient satisfaction, and perception of rotational movements during function. Our primary hypothesis was that the OHRQoL of edentulous individuals will improve after receipt of mandibular three-implant overdentures.
tures with overdentures retained by three implants placed in the anterior mandible during the years of 2006–2009. The restorative procedures included a conventional loading protocol; three fixtures (Osolndal, seoSpeedTM; DENTSPLY Implants, M€ Sweden or TiUnite RP MKIII Nobel Biocare AB, Gothenburg, Sweden or Straumann SLA active; Basel, Switzerland) were placed between the mental foramina and capped with healing abutments. The conventional complete mandibular dentures were then relined with a soft material. After 2 months, the patients received their new prostheses (mandibular implant overdentures opposed by maxillary dentures) from their referring dentists. Two different prosthetic retentive systems were used, ball/o-ring (plastic) attachments (Astra Tech Implant systemTM; Molndal, Sweden, Br anemark Systemâ; Nobel Biocare AB, Go¨teborg, Sweden, Straumann; Basel, Switzerland, ACE; Brockton, MA, USA.) and Locator-type stud attachments (Astra Tech Implant systemTM, Branemark System; Nobel Biocare). The eligibility criteria included as follows: (1) being 18 years or older, (2) wearing a conventional denture before implant placement and wearing a mandibular implant overdenture with three resilient attachments opposed by a conventional maxillary denture for at least 3 months. Participants were excluded from participating if they were unable to return for evaluation/study recall sessions. A limited set of data from the available clinical and research records were extracted, and a follow-up evaluation was conducted in July 2009. The following outcome variables were evaluated: 1. Oral health-related quality of life (OHRQoL). 2. Denture satisfaction. 3. Perceived rocking movements.
Measurement instruments
Material and methods Participants, treatment, and outcomes
This manuscript describes a quasi-experimental, practice-based study investigating edentulous patients treated in a specialized clinic in oral implantology in Quebec City, QC, Canada. The Universit e de Montreal Institutional Review Board approved the protocol of this study, and an informed written consent was obtained from each study participant. The participants were edentulous adults who had replaced their mandibular conventional den-
2 |
Clin. Oral Impl. Res. 0, 2014 / 1–5
All patients rated their OHRQoL using the Oral Health Impact Profile (OHIP-20) (Awad et al. 2003a,b). The OHIP-20 is a validated disease-specific 20-item questionnaire including seven domains: functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap. The items were rated on six-point Likert-type scales (never, rarely, occasionally, often, very often, or all of the time). The range of the scale is 20–120 points, with lower scores indicating better OHRQoL. A pre-treatment assessment
by the OHIP-20 was available before commencing this study, as part of the clinical examination forms. Post-treatment denture satisfaction ratings were obtained using a denture satisfaction five-point Likert scale (de Grandmont et al. 1994; Allen et al. 2006), with a score of 1 representing the most favourable and a score of 5 representing the least favourable response (1, totally satisfied: no complaints; 2, very satisfied: some complaints; 3, moderately satisfied; 4, very dissatisfied: considerable complaints; 5, totally dissatisfied: could not be worse). This is a validated questionnaire that includes items on ease of cleaning, ability to speak, comfort, aesthetics, stability, ability to chew, and general satisfaction. Additional items were included in the questionnaire to assess rocking movements (binary) and rating of satisfaction regarding rocking movements (five-point Likert scales).
Statistical analyses
Assuming that the minimal clinically important difference in the OHIP-20 total score is 10 units (SD 25) (Allen et al. 2009) across all domains affected by the provision of a new prosthesis that correspond to a moderate effect size, a sample size of 130 patients will ensure a power of 95% at an alpha level of 0.05. Descriptive statistics were used to identify study participants’ characteristics and to provide summary statistics. Paired t-tests were used to compare pre- to post-OHIP scores. Change scores were calculated for OHIP scores to determine the magnitude of change from pre- to post-treatment by subtracting baseline from follow-up ratings, using the formula DT0 1 = T1 T0. The effect size was calculated using the following formula: OHIPT0 OHIPT1/SDT0. Post-treatment satisfaction ratings were dichotomized, and chi-square tests were used to determine their associations with explanatory variables. Subgroup analyses include the evaluation of ratings of satisfaction with perceived rocking movements. Fisher’s exact test and Pearson correlation coefficients were used to analyse the strength of the association between ratings of rotational movements and prosthesis satisfaction. Hierarchical linear regression analyses were used to evaluate the effects of explanatory variables (demographic variables, type of fixtures, and type of attachment system) on treatment outcomes. The level of significance was set at 0.05, and all data were analysed using SPSS v.19 (SPSS Inc., IBM Corporation, Somers, NY, USA).
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Emami et al Mandibular three-implant overdenture
Results In total, 213 patient records (145 F, 68 M) were examined, and 135 (92 F, 43 M) met the eligibility criteria. The mean age of the patients was 61.6 7.9 years, with the majority being female (68.1%). Other characteristics of the studied sample are shown in Table 1. Among the three implant systems used, OsseoSpeed was used most frequently (DENTSPLY Implants) (n = 109, 80.8%), followed by the TiUnite Mk III (Nobel Biocare AB) (n = 24, 17.7%) and the Straumann SLActive (Straumann) (n = 2, 1.5%). Two retentive systems were used: ball (83.7%) and locator stud attachments (16.3%). All participants demonstrated statistically significant improvements (P < 0.0001, paired t-test) in all seven domains of the OHIP from pre- to post-treatment (Table 2). The regression model showed that the mean of the OHIP post-total score was not influenced by age, gender, type of fixtures, or type of attachment. Two variables, pre-treatment OHIP scores, and rotational movements were significant influences and explained 58% of
Table 1. Sample characteristics (n = 135) 61.6 7.9 years
Age Gender Female Language French Marital status Married/Partnered Single/separated/divorced/widow No answer Living status Alone With family/others No answer Education Elementary/High school College/University No answer Income
Patient perceptions of the mandibular three-implant overdenture: a practicebased study
Authors’ affiliations: Elham Emami, Department of Restorative Dentistry, Faculty of Dentistry, Universite de Montreal, Montreal, QC, Canada Department of Social and Preventive Medicine, School of Public Health, Universite de Montreal, Montreal, QC, Canada Raphael F. de Souza, Department of Dental Materials and Prosthodontics, Ribeir~ao Preto Dental School, University of S~ao Paulo, Ribeir~ao Preto, Brazil Jacques Bernier, Centre d’Implantologie Ste-Foy, Quebec City, QC, Canada Pierre Rompr e, D epartement de Stomatologie, Faculte de M edecine Dentaire, Universite de Montreal, Montreal, QC, Canada Jocelyne S. Feine, Oral Health and Society Research Unit, Faculty of Dentistry, McGill University, Montreal, QC, Canada Department of Epidemiology and Biostatistics and Department of Oncology, Faculty of Medicine, McGill University, Montreal, QC, Canada
Key words: implant, implant overdenture, oral health-related quality of life, patient
Corresponding author: Elham Emami, DDS, MSc, PhD Department of Restorative Dentistry, Faculty of Dentistry, Department of Social and Preventive Medicine, School of Public Health, Universite de Montreal, Pavillon Roger-Gaudry, local C-219, 2900 Edouard-Montpetit. H3T 1J4 Montreal, QC, Canada Tel.: +1514343 6053 Fax: +1 514343 2233. e-mail: [email protected]
significant improvements in all seven domains of the OHIP-20 from pre- to post-treatment (total
satisfaction Abstract Objectives: Although three-implant overdentures have often been used in clinical practice, there are few studies to support this approach. Therefore, this study aimed to determine the magnitude of change in ratings of oral health-related quality of life and to assess patients’ satisfaction ratings with mandibular three-implant overdentures. Materials and methods: This quasi-experimental study examined oral health-related quality of life and satisfaction with prosthesis in 135 edentate participants (mean age 61.6 7.9 years) who received mandibular three-implant overdentures from 2006 to 2009 in a private practice in Quebec, Canada. Data were collected from individual’s dental records and a follow-up survey. The Oral Health Impact Profile (OHIP-20) was used to assess oral health-related quality of life at baseline and at follow-up. Satisfaction with the mandibular prostheses and perception of rocking movements were measured by use of a denture satisfaction questionnaire at follow-up. Descriptive statistics, bivariate and multivariate statistical analyses were used to analyse the data. Results: Individuals who received mandibular three-implant overdentures had statistically OHIP change score
25.1 P < 0.001). Pre-treatment OHIP scores and rotational movement explained
58% of the variance in the OHIP’s change score (P ≤ 0.05). More than three quarters of the sample population (75.6%) were completely satisfied with their three-implant overdentures, and 81.5% reported having no rocking movement. General satisfaction with the prostheses was not influenced by gender, type of fixture, or type of attachment. Conclusions: The treatment of edentulism by three-implant overdentures has favourable patientbased outcomes, with negligible perceptions of rotational movement. However, further research is needed to compare the efficacy of this alternative to other treatment modalities, such as the two-implant overdenture.
Date: Accepted 19 January 2014 To cite this article: Emami E, de Souza RF, Bernier J, Rompr e P, Feine JS. Patient perceptions of the mandibular three-implant overdenture: a practice-based study. Clin. Oral Impl. Res. 00, 2014, 1–5 doi: 10.1111/clr.12351
Although conventional dentures have been shown to be somewhat effective in reducing the major functional impairments associated with edentulism, they have inadequate retention, resulting in looseness and discomfort (Awad et al. 2000, 2003a,b). During the past decade, clinical studies have highlighted the cost-effectiveness of mandibular overdentures retained by two implants as a treatment option for edentulous patients (Awad et al. 2000, 2003a,b). Two-implant overdentures offer greater retention than conventional dentures, thus improving well-being and oral health-related quality of life (OHRQoL) to levels within the expectations of the edentulous population (Awad et al. 2003a,b; Raghoebar et al. 2003; Emami et al. 2009; Jabbour et al. 2011).
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
The advantages of two-implant overdentures have led to two international consensuses on the management of edentulism, namely the McGill and York Consensuses. Both have resulted in statements recommending these as the minimal standard of care for edentulous patients (Feine et al. 2002; Thomason et al. 2009, 2012). The viability of stud attachments (Cune et al. 2010) and immediate loading (Buttel et al. 2012) for twoimplant retained prostheses further increases their accessibility, due to the potential reduction in treatment time and complexity. One limitation of two-implant overdentures, however, is the potential for anterior/ posterior rotation of the denture base around the attachments. This issue was raised by clinicians and investigated in clinical
1
Emami et al Mandibular three-implant overdenture
research. In the study by Kimoto et al. (2009), the participants reported a rocking movement of their overdentures retained by two implants with ball attachments. This rotational movement was correlated with decreased chewing ability that could compromise a patient’s satisfaction and OHRQoL. The concept of three implants to support a mandibular denture with separate stud attachments or splinted implants has been introduced since 1980s, and this modality of treatment has been widely used in the clinic (Hobo et al. 1989; Renouard & Rangert 1999) (Zarb et al. 2004; Misch 2008). Although adding an additional implant increases the cost of treatment, this increased cost is still less than the cost of more expensive treatment alternatives, such as fixed implant restorations or removable prostheses supported by four or more implants. The addition of a third implant in the symphyseal region could provide indirect retention for the denture and preclude rotational movement without resulting in higher strain on the denturebearing mucosa, abutments, implants, or ridge (Liu et al. 2013). High implant survival and success rates, healthy peri-implant tissues (Parel 1986; Engquist et al. 1988; Mericske-Stern 1990), and favourable periimplant rates of bone loss (Deporter et al. 2002) have been reported for mandibular three-implant overdentures. However, a literature search demonstrates that there is still little research regarding patient perceptions of three-implant overdentures (Geckili et al. 2011). Therefore, the aim of this study was to provide patient-reported data on the effectiveness of mandibular three-implant overdentures. More specifically, the chosen outcomes were OHRQoL, patient satisfaction, and perception of rotational movements during function. Our primary hypothesis was that the OHRQoL of edentulous individuals will improve after receipt of mandibular three-implant overdentures.
tures with overdentures retained by three implants placed in the anterior mandible during the years of 2006–2009. The restorative procedures included a conventional loading protocol; three fixtures (Osolndal, seoSpeedTM; DENTSPLY Implants, M€ Sweden or TiUnite RP MKIII Nobel Biocare AB, Gothenburg, Sweden or Straumann SLA active; Basel, Switzerland) were placed between the mental foramina and capped with healing abutments. The conventional complete mandibular dentures were then relined with a soft material. After 2 months, the patients received their new prostheses (mandibular implant overdentures opposed by maxillary dentures) from their referring dentists. Two different prosthetic retentive systems were used, ball/o-ring (plastic) attachments (Astra Tech Implant systemTM; Molndal, Sweden, Br anemark Systemâ; Nobel Biocare AB, Go¨teborg, Sweden, Straumann; Basel, Switzerland, ACE; Brockton, MA, USA.) and Locator-type stud attachments (Astra Tech Implant systemTM, Branemark System; Nobel Biocare). The eligibility criteria included as follows: (1) being 18 years or older, (2) wearing a conventional denture before implant placement and wearing a mandibular implant overdenture with three resilient attachments opposed by a conventional maxillary denture for at least 3 months. Participants were excluded from participating if they were unable to return for evaluation/study recall sessions. A limited set of data from the available clinical and research records were extracted, and a follow-up evaluation was conducted in July 2009. The following outcome variables were evaluated: 1. Oral health-related quality of life (OHRQoL). 2. Denture satisfaction. 3. Perceived rocking movements.
Measurement instruments
Material and methods Participants, treatment, and outcomes
This manuscript describes a quasi-experimental, practice-based study investigating edentulous patients treated in a specialized clinic in oral implantology in Quebec City, QC, Canada. The Universit e de Montreal Institutional Review Board approved the protocol of this study, and an informed written consent was obtained from each study participant. The participants were edentulous adults who had replaced their mandibular conventional den-
2 |
Clin. Oral Impl. Res. 0, 2014 / 1–5
All patients rated their OHRQoL using the Oral Health Impact Profile (OHIP-20) (Awad et al. 2003a,b). The OHIP-20 is a validated disease-specific 20-item questionnaire including seven domains: functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap. The items were rated on six-point Likert-type scales (never, rarely, occasionally, often, very often, or all of the time). The range of the scale is 20–120 points, with lower scores indicating better OHRQoL. A pre-treatment assessment
by the OHIP-20 was available before commencing this study, as part of the clinical examination forms. Post-treatment denture satisfaction ratings were obtained using a denture satisfaction five-point Likert scale (de Grandmont et al. 1994; Allen et al. 2006), with a score of 1 representing the most favourable and a score of 5 representing the least favourable response (1, totally satisfied: no complaints; 2, very satisfied: some complaints; 3, moderately satisfied; 4, very dissatisfied: considerable complaints; 5, totally dissatisfied: could not be worse). This is a validated questionnaire that includes items on ease of cleaning, ability to speak, comfort, aesthetics, stability, ability to chew, and general satisfaction. Additional items were included in the questionnaire to assess rocking movements (binary) and rating of satisfaction regarding rocking movements (five-point Likert scales).
Statistical analyses
Assuming that the minimal clinically important difference in the OHIP-20 total score is 10 units (SD 25) (Allen et al. 2009) across all domains affected by the provision of a new prosthesis that correspond to a moderate effect size, a sample size of 130 patients will ensure a power of 95% at an alpha level of 0.05. Descriptive statistics were used to identify study participants’ characteristics and to provide summary statistics. Paired t-tests were used to compare pre- to post-OHIP scores. Change scores were calculated for OHIP scores to determine the magnitude of change from pre- to post-treatment by subtracting baseline from follow-up ratings, using the formula DT0 1 = T1 T0. The effect size was calculated using the following formula: OHIPT0 OHIPT1/SDT0. Post-treatment satisfaction ratings were dichotomized, and chi-square tests were used to determine their associations with explanatory variables. Subgroup analyses include the evaluation of ratings of satisfaction with perceived rocking movements. Fisher’s exact test and Pearson correlation coefficients were used to analyse the strength of the association between ratings of rotational movements and prosthesis satisfaction. Hierarchical linear regression analyses were used to evaluate the effects of explanatory variables (demographic variables, type of fixtures, and type of attachment system) on treatment outcomes. The level of significance was set at 0.05, and all data were analysed using SPSS v.19 (SPSS Inc., IBM Corporation, Somers, NY, USA).
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Emami et al Mandibular three-implant overdenture
Results In total, 213 patient records (145 F, 68 M) were examined, and 135 (92 F, 43 M) met the eligibility criteria. The mean age of the patients was 61.6 7.9 years, with the majority being female (68.1%). Other characteristics of the studied sample are shown in Table 1. Among the three implant systems used, OsseoSpeed was used most frequently (DENTSPLY Implants) (n = 109, 80.8%), followed by the TiUnite Mk III (Nobel Biocare AB) (n = 24, 17.7%) and the Straumann SLActive (Straumann) (n = 2, 1.5%). Two retentive systems were used: ball (83.7%) and locator stud attachments (16.3%). All participants demonstrated statistically significant improvements (P < 0.0001, paired t-test) in all seven domains of the OHIP from pre- to post-treatment (Table 2). The regression model showed that the mean of the OHIP post-total score was not influenced by age, gender, type of fixtures, or type of attachment. Two variables, pre-treatment OHIP scores, and rotational movements were significant influences and explained 58% of
Table 1. Sample characteristics (n = 135) 61.6 7.9 years
Age Gender Female Language French Marital status Married/Partnered Single/separated/divorced/widow No answer Living status Alone With family/others No answer Education Elementary/High school College/University No answer Income
