Philipp Sahrmann Valerie Ronay Deborah Hofer Thomas Attin Ronald E. Jung Patrick R. Schmidlin
Authors’ affiliations: Philipp Sahrmann, Valerie Ronay, Deborah Hofer, Thomas Attin, Patrick R. Schmidlin, Clinic of Preventive Dentistry Periodontology and Cariology, Center of Dental and Oral Medicine and Maxillofacial Surgery, University of Zurich, Zurich, Switzerland Ronald E. Jung, Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental and Oral Medicine and Maxillofacial Surgery, University of Zurich, Zurich, Switzerland
In vitro cleaning potential of three different implant debridement methods
Key words: air flow, debridement, nonsurgical, peri-implantitis Abstract Objectives: To assess the cleaning potential of three different instrumentation methods commonly used for implant surface decontamination in vitro, using a bone defect-simulating model. Materials and methods: Dental implants were stained with indelible ink and mounted in resin models, which represented standardized peri-implantitis defects with different bone defect angulations (30, 60 and 90°). Cleaning procedures were performed by either an experienced dental hygienist or a 2nd-year postgraduate student. The treatment was repeated 20 times for each
Corresponding author: Dr. Philipp Sahrmann Clinic of Preventive Dentistry, Periodontology and Cariology Plattenstrasse 11 8032 Z€ urich Switzerland Tel.:+41 44 634 32 84 Fax: +41 44 634 43 08 e-mail: [email protected]
instrumentation, that is, with a Gracey curette, an ultrasonic device and an air powder abrasive device (PAD) with glycine powder. After each run, implants were removed and images were taken to detect color remnants in order to measure planimetrically the cumulative uncleaned surface area. SEM images were taken to assess micromorphologic surface changes (magnification 10,0009). Results were tested for statistical differences using two-way ANOVA and Bonferroni correction. Results: The areas of uncleaned surfaces (%, mean standard deviations) for curettes, ultrasonic tips, and airflow accounted for 24.1 4.8%, 18.5 3.8%, and 11.3 5.4%, respectively. These results were statistically significantly different (P < 0.0001). The cleaning potential of the airflow device increased with wider defects. SEM evaluation displayed distinct surface alterations after instrumentation with steel tips, whereas glycine powder instrumentation had only a minute effect on the surface topography. Conclusion: Within the limitations of the present in vitro model, airflow devices using glycine powders seem to constitute an efficient therapeutic option for the debridement of implants in peri-implantitis defects. Still, some uncleaned areas remained. In wide defects, differences between instruments are more accentuated.
Date: Accepted 30 November 2013 To cite this article: Sahrmann P, Ronay V, Hofer D, Attin T, Jung RE, Schmidlin PR. In vitro cleaning potential of three different implant debridement methods. Clin. Oral Impl. Res. 00, 2013, 1–6 doi: 10.1111/clr.12322
Implant therapy has become a successful standard treatment in dentistry (Jung et al. 2008; Romanos et al. 2012), and thus, an increasing number of implants is being placed (http://www.aaid.com; Brennan et al. 2010). However, biological and technical complications are a clinical reality as well, and peri-implantitis has been shown to occur in 28-56% of patients with dental implants (Zitzmann & Berglundh 2008), thereby consituting the main biologic reason for long-term implant failure (Aglietta et al. 2009; Jung et al. 2008). As a consequence, peri-implantitis cases emerge as well in the general dental practice, and peri-implantitis treatment itself is becoming more and more an integral part of standard treatment protocols (Schmidlin et al. 2012).
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
The primary etiologic factor for these inflammatory conditions is the establishment of bacterial biofilms on the implant surfaces (Heitz-Mayfield & Lang 2010). Within this biofilm, bacteria show an extreme resistance to topical disinfectants and systemic antibiotics (Stewart & Costerton 2001). Accordingly, the aim of any cause-related therapy still remains the effective mechanical removal of the intact biofilm (Mombelli & Lang 1994). For this purpose, manual curettes, ultrasonic and air-polishing devices are commonly used (Romanos & Weitz 2012; Mombelli et al. 2012). However, due to the special implant and defect-specific characteristics, access to all affected areas is limited. As a consequence, nonsurgical techniques still do not provide predictable and successful outcomes,
1
Sahrmann et al Surface access in peri-implantitis defects
especially in advanced cases (Romanos & Weitz 2012; Renvert et al. 2008). Hence, mechanical debridement in combination with a surgical approach is often necessary to facilitate the mechanical debridement (Romanos & Weitz 2012). However, studies on periodontal treatment concordantly show that even when the comparatively easy to clean root surface is accessible and visible, instrumentation is still a demanding task and also relies on the operator’s skills, training and experience (Brayer et al. 1989; Ruhling et al. 2002; Kocher et al. 1997). Another challenge is the fact that ideal surface decontamination should not only reach all contaminated surfaces, but that the efforts to effectively clean the surface ideally should not change the implant surface micromorphology in order not to interfere with the biocompatibility. This is an issue becoming crucial when regenerative techniques are planned. Unfortunately, there is still a lack of evidence regarding the most efficacious instrumentation modality with regard to the addressed implant-specific problems, and further research on this topic is being demanded continuously (Esposito et al. 2002; RoosJansaker et al. 2003; Sahrmann et al. 2013). In a recent study, we showed that an air powder abrasion device (PAD) with glycine powder provided good access to implant surfaces when using different defect models (Sahrmann et al. 2013). However, a comparison with other methods was not assessed, and the problem of concomitant surface changes and the influence of the operator were also not addressed. Therefore, it was the aim of this study to investigate the cleaning potential of three different instrumentation methods in vitro using a bone defect-simulating model (primary outcome) by assessing the color removal of stained implants during open flap debridement. As secondary parameters, the influence of the operator and changes in the surface micromorphology were also assessed. The null hypothesis was that all instrumentations showed comparable outcomes in terms of the cleaning potential and that both the defect morphologies and the operator had no impact on these treatments and furthermore that there was a comparable degree of surface alterations after instrumentation.
6.5 mm (Tapered Effect WN, Straumann, Basel, Switzerland) were dip-coated with red indelible, noncovering ink (Staedler permanent Lumocolor, N€ urnberg, Germany) to simulate an optically identifiable plaque accumulation on the machined collar and the rough surface with the threads according to a recently published protocol (Sahrmann et al. 2013). After dipping, a complete and homogeneous, clearly visible red stain was present on both the rough and the machined surfaces. Implants were mounted in resin bases simulating crater-shaped periimplantitis defects of three different angulations (30, 60 und 90°, see Fig. 1). The defect depth was set at 6 mm, and implants were positioned in such a way that the rough surfaces leveled with the upper edge of the defect. Implants were horizontally fixed using screws, which allowed for an adequate fixation of the implants during the instrumentation and an easy removal afterward. Test treatments
Twenty implants were used per treatment modality, defect model and investigator. Three different instruments were used (Fig. 1):
• • •
A Gracey steel curette (Deppeler, Rolle, Switzerland) with slim working tips Nr. 11/12. An ultrasonic device with a steel tip (ADS1, EMS, Nyon Switzerland) at maximum power settings. An air powder abrasive device (Airflow Master, EMS, Nyon, Switzerland) with glycine powder (PerioFlow, EMS, Nyon, Switzerland) at maximum settings for both “power” and “lavage”. For the treatment, a nozzle for supragingival application was used (EMS Air-FlowMaster nozzle, EMS, Nyon, Switzerland).
During surface cleaning, the working distance and angulation of the working piece were individually chosen by the operators without any restrictions. After instrumentation, powder remnants were removed by gentle rinsing with water for 10 s. During the treatment, the models could be turned and held in any position, which seemed suitable for the operators to achieve optimal access to the surface. The treatment time was restricted to 2 min for each instrumentation type, and the working time was controlled and documented using a stopwatch. Each cleaning method was performed by a dental hygienist with over 35 years of clinical experience and a 2nd-year postdoc student in periodontology. Scanning electron microscopy of the instrumented surfaces was performed. For this purpose, specimens were cleaned with water spray, gold sputtered (layer thickness: 6 nm) and surface topography was evaluated under a SEM (Carl Zeiss Supra 50 VP FESEM, Carl Zeiss, Oberkochen, Germany) operating at 10 kV with a working distance of 9 mm. Pictures of the machined implant shoulder and the instrumented SLA surface areas of each treated implant were taken at 5009 and 10,0009 magnification. Surfaces of an untreated implant served as control. Assessment of unaccessed surface remnants
After each run, implants were removed from the bases. Loosened ink particles and water were removed by gentle rinsing with water and air. Digital color photos were taken vertically to the implant axis, employing standardized parameters (dark chamber, ISO 100, aperture f/32, shutter speed 1/250 s, distance 31.4 cm with a Nikon D200, Tokyo, Japan, ring flash EM-140 DG; Metz MB 15 MS-1 Makroslave digital flash, Zirndorf, Germany, with power settings 1/2) from one side and
Materials and methods (a)
(b)
(c)
(d)
(e)
(f)
Preparation of the implants/in vitro models
Implants with a length of 12 mm, a diameter of 4.8 mm, and a shoulder diameter of
2 |
Clin. Oral Impl. Res. 0, 2013 / 1–6
Fig. 1. Defect models with an aperture of 30°, 60°, and 90° (a, b, c) and different debridement instruments: Ultrasound tip (steel tip, d), Gracey curette (steel, e) and air powder abrasive device (charged with glycine powder, f).
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Sahrmann et al Surface access in peri-implantitis defects
the opposite aspect (180° turn). Ink remnants on the surface were detected using an image processing software (Adobe Photoshop Elements Vs. 9.0.3, Adobe Systems Inc., San Jos e, CA, USA). The cumulative remnant area per implant was calculated using a custom-programmed planimetry software (PPK, Z€ urich, Switzerland) (Rasband 1997) (see Fig. 2). Implant surfaces were then completely cleaned by twofold tilting in ethanol (97%). After optical control of complete ink removal (magnifying lenses 4.39, Carl Zeiss AG, Feldbach, Switzerland), the air-dried implants were restained in the same way as described before. Air flow debridement was performed first on all implants, followed by the ultrasonic and the curette debridement. Statistics
Normality of data distribution was tested using Kolmogorov–Smirnov and Shapiro– Wilk tests. Means and standard deviations of the percentages of uncleaned surface were calculated. Differences between different defect angulations, operators, and instruments were tested by nonparametric two-way ANOVA with Bonferroni correction. In all tests, all p-values lower than 5% were regarded as statistically significant.
Results Regardless of the instrument used, remaining ink stain was discernible on all samples. The cumulative surface with ink remnants showed considerable deviation in each subgroup analyzed. The accessibility of the implant surfaces in terms of stain removal showed significant differences depending on the employed device. The testing for normality indicated no violation of the assumption of normality. Powder abrasion showed the least remnants (11.3 5.4%), followed by ultrasonic (18.5 3.8%) and manual (24.1 4.8%) instrumentation. These results were statistically significantly different (P
Authors’ affiliations: Philipp Sahrmann, Valerie Ronay, Deborah Hofer, Thomas Attin, Patrick R. Schmidlin, Clinic of Preventive Dentistry Periodontology and Cariology, Center of Dental and Oral Medicine and Maxillofacial Surgery, University of Zurich, Zurich, Switzerland Ronald E. Jung, Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental and Oral Medicine and Maxillofacial Surgery, University of Zurich, Zurich, Switzerland
In vitro cleaning potential of three different implant debridement methods
Key words: air flow, debridement, nonsurgical, peri-implantitis Abstract Objectives: To assess the cleaning potential of three different instrumentation methods commonly used for implant surface decontamination in vitro, using a bone defect-simulating model. Materials and methods: Dental implants were stained with indelible ink and mounted in resin models, which represented standardized peri-implantitis defects with different bone defect angulations (30, 60 and 90°). Cleaning procedures were performed by either an experienced dental hygienist or a 2nd-year postgraduate student. The treatment was repeated 20 times for each
Corresponding author: Dr. Philipp Sahrmann Clinic of Preventive Dentistry, Periodontology and Cariology Plattenstrasse 11 8032 Z€ urich Switzerland Tel.:+41 44 634 32 84 Fax: +41 44 634 43 08 e-mail: [email protected]
instrumentation, that is, with a Gracey curette, an ultrasonic device and an air powder abrasive device (PAD) with glycine powder. After each run, implants were removed and images were taken to detect color remnants in order to measure planimetrically the cumulative uncleaned surface area. SEM images were taken to assess micromorphologic surface changes (magnification 10,0009). Results were tested for statistical differences using two-way ANOVA and Bonferroni correction. Results: The areas of uncleaned surfaces (%, mean standard deviations) for curettes, ultrasonic tips, and airflow accounted for 24.1 4.8%, 18.5 3.8%, and 11.3 5.4%, respectively. These results were statistically significantly different (P < 0.0001). The cleaning potential of the airflow device increased with wider defects. SEM evaluation displayed distinct surface alterations after instrumentation with steel tips, whereas glycine powder instrumentation had only a minute effect on the surface topography. Conclusion: Within the limitations of the present in vitro model, airflow devices using glycine powders seem to constitute an efficient therapeutic option for the debridement of implants in peri-implantitis defects. Still, some uncleaned areas remained. In wide defects, differences between instruments are more accentuated.
Date: Accepted 30 November 2013 To cite this article: Sahrmann P, Ronay V, Hofer D, Attin T, Jung RE, Schmidlin PR. In vitro cleaning potential of three different implant debridement methods. Clin. Oral Impl. Res. 00, 2013, 1–6 doi: 10.1111/clr.12322
Implant therapy has become a successful standard treatment in dentistry (Jung et al. 2008; Romanos et al. 2012), and thus, an increasing number of implants is being placed (http://www.aaid.com; Brennan et al. 2010). However, biological and technical complications are a clinical reality as well, and peri-implantitis has been shown to occur in 28-56% of patients with dental implants (Zitzmann & Berglundh 2008), thereby consituting the main biologic reason for long-term implant failure (Aglietta et al. 2009; Jung et al. 2008). As a consequence, peri-implantitis cases emerge as well in the general dental practice, and peri-implantitis treatment itself is becoming more and more an integral part of standard treatment protocols (Schmidlin et al. 2012).
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
The primary etiologic factor for these inflammatory conditions is the establishment of bacterial biofilms on the implant surfaces (Heitz-Mayfield & Lang 2010). Within this biofilm, bacteria show an extreme resistance to topical disinfectants and systemic antibiotics (Stewart & Costerton 2001). Accordingly, the aim of any cause-related therapy still remains the effective mechanical removal of the intact biofilm (Mombelli & Lang 1994). For this purpose, manual curettes, ultrasonic and air-polishing devices are commonly used (Romanos & Weitz 2012; Mombelli et al. 2012). However, due to the special implant and defect-specific characteristics, access to all affected areas is limited. As a consequence, nonsurgical techniques still do not provide predictable and successful outcomes,
1
Sahrmann et al Surface access in peri-implantitis defects
especially in advanced cases (Romanos & Weitz 2012; Renvert et al. 2008). Hence, mechanical debridement in combination with a surgical approach is often necessary to facilitate the mechanical debridement (Romanos & Weitz 2012). However, studies on periodontal treatment concordantly show that even when the comparatively easy to clean root surface is accessible and visible, instrumentation is still a demanding task and also relies on the operator’s skills, training and experience (Brayer et al. 1989; Ruhling et al. 2002; Kocher et al. 1997). Another challenge is the fact that ideal surface decontamination should not only reach all contaminated surfaces, but that the efforts to effectively clean the surface ideally should not change the implant surface micromorphology in order not to interfere with the biocompatibility. This is an issue becoming crucial when regenerative techniques are planned. Unfortunately, there is still a lack of evidence regarding the most efficacious instrumentation modality with regard to the addressed implant-specific problems, and further research on this topic is being demanded continuously (Esposito et al. 2002; RoosJansaker et al. 2003; Sahrmann et al. 2013). In a recent study, we showed that an air powder abrasion device (PAD) with glycine powder provided good access to implant surfaces when using different defect models (Sahrmann et al. 2013). However, a comparison with other methods was not assessed, and the problem of concomitant surface changes and the influence of the operator were also not addressed. Therefore, it was the aim of this study to investigate the cleaning potential of three different instrumentation methods in vitro using a bone defect-simulating model (primary outcome) by assessing the color removal of stained implants during open flap debridement. As secondary parameters, the influence of the operator and changes in the surface micromorphology were also assessed. The null hypothesis was that all instrumentations showed comparable outcomes in terms of the cleaning potential and that both the defect morphologies and the operator had no impact on these treatments and furthermore that there was a comparable degree of surface alterations after instrumentation.
6.5 mm (Tapered Effect WN, Straumann, Basel, Switzerland) were dip-coated with red indelible, noncovering ink (Staedler permanent Lumocolor, N€ urnberg, Germany) to simulate an optically identifiable plaque accumulation on the machined collar and the rough surface with the threads according to a recently published protocol (Sahrmann et al. 2013). After dipping, a complete and homogeneous, clearly visible red stain was present on both the rough and the machined surfaces. Implants were mounted in resin bases simulating crater-shaped periimplantitis defects of three different angulations (30, 60 und 90°, see Fig. 1). The defect depth was set at 6 mm, and implants were positioned in such a way that the rough surfaces leveled with the upper edge of the defect. Implants were horizontally fixed using screws, which allowed for an adequate fixation of the implants during the instrumentation and an easy removal afterward. Test treatments
Twenty implants were used per treatment modality, defect model and investigator. Three different instruments were used (Fig. 1):
• • •
A Gracey steel curette (Deppeler, Rolle, Switzerland) with slim working tips Nr. 11/12. An ultrasonic device with a steel tip (ADS1, EMS, Nyon Switzerland) at maximum power settings. An air powder abrasive device (Airflow Master, EMS, Nyon, Switzerland) with glycine powder (PerioFlow, EMS, Nyon, Switzerland) at maximum settings for both “power” and “lavage”. For the treatment, a nozzle for supragingival application was used (EMS Air-FlowMaster nozzle, EMS, Nyon, Switzerland).
During surface cleaning, the working distance and angulation of the working piece were individually chosen by the operators without any restrictions. After instrumentation, powder remnants were removed by gentle rinsing with water for 10 s. During the treatment, the models could be turned and held in any position, which seemed suitable for the operators to achieve optimal access to the surface. The treatment time was restricted to 2 min for each instrumentation type, and the working time was controlled and documented using a stopwatch. Each cleaning method was performed by a dental hygienist with over 35 years of clinical experience and a 2nd-year postdoc student in periodontology. Scanning electron microscopy of the instrumented surfaces was performed. For this purpose, specimens were cleaned with water spray, gold sputtered (layer thickness: 6 nm) and surface topography was evaluated under a SEM (Carl Zeiss Supra 50 VP FESEM, Carl Zeiss, Oberkochen, Germany) operating at 10 kV with a working distance of 9 mm. Pictures of the machined implant shoulder and the instrumented SLA surface areas of each treated implant were taken at 5009 and 10,0009 magnification. Surfaces of an untreated implant served as control. Assessment of unaccessed surface remnants
After each run, implants were removed from the bases. Loosened ink particles and water were removed by gentle rinsing with water and air. Digital color photos were taken vertically to the implant axis, employing standardized parameters (dark chamber, ISO 100, aperture f/32, shutter speed 1/250 s, distance 31.4 cm with a Nikon D200, Tokyo, Japan, ring flash EM-140 DG; Metz MB 15 MS-1 Makroslave digital flash, Zirndorf, Germany, with power settings 1/2) from one side and
Materials and methods (a)
(b)
(c)
(d)
(e)
(f)
Preparation of the implants/in vitro models
Implants with a length of 12 mm, a diameter of 4.8 mm, and a shoulder diameter of
2 |
Clin. Oral Impl. Res. 0, 2013 / 1–6
Fig. 1. Defect models with an aperture of 30°, 60°, and 90° (a, b, c) and different debridement instruments: Ultrasound tip (steel tip, d), Gracey curette (steel, e) and air powder abrasive device (charged with glycine powder, f).
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Sahrmann et al Surface access in peri-implantitis defects
the opposite aspect (180° turn). Ink remnants on the surface were detected using an image processing software (Adobe Photoshop Elements Vs. 9.0.3, Adobe Systems Inc., San Jos e, CA, USA). The cumulative remnant area per implant was calculated using a custom-programmed planimetry software (PPK, Z€ urich, Switzerland) (Rasband 1997) (see Fig. 2). Implant surfaces were then completely cleaned by twofold tilting in ethanol (97%). After optical control of complete ink removal (magnifying lenses 4.39, Carl Zeiss AG, Feldbach, Switzerland), the air-dried implants were restained in the same way as described before. Air flow debridement was performed first on all implants, followed by the ultrasonic and the curette debridement. Statistics
Normality of data distribution was tested using Kolmogorov–Smirnov and Shapiro– Wilk tests. Means and standard deviations of the percentages of uncleaned surface were calculated. Differences between different defect angulations, operators, and instruments were tested by nonparametric two-way ANOVA with Bonferroni correction. In all tests, all p-values lower than 5% were regarded as statistically significant.
Results Regardless of the instrument used, remaining ink stain was discernible on all samples. The cumulative surface with ink remnants showed considerable deviation in each subgroup analyzed. The accessibility of the implant surfaces in terms of stain removal showed significant differences depending on the employed device. The testing for normality indicated no violation of the assumption of normality. Powder abrasion showed the least remnants (11.3 5.4%), followed by ultrasonic (18.5 3.8%) and manual (24.1 4.8%) instrumentation. These results were statistically significantly different (P
