Learning root debridement with curettes and power-driven instruments in vitro: the role of operator motivation and self-assessment

Preclinical teaching of periodontal surgical concepts using common instructional models: A comparative assessment

OBJECTIVES

Some commonly used models utilized for teaching periodontal surgical techniques to dental students include pig mandible and periodontal typodonts. Currently, no study compares the learning and teaching outcomes following the use of one model to the other. This study is aimed at evaluating the effectiveness of the preclinical laboratory component on student understanding of concepts taught in the periodontal surgical course and assessing students' and faculty members' satisfaction with the instructional models.

METHODS

As part of the surgical periodontics course, 98 students took the final exam, with eighty students participating in only the pig mandible session and twenty-three students participating in both the pig jaw mandible and an additional session utilizing periodontal typodonts under the supervision of ten periodontal faculty members. Examination scores of students attending or not attending the laboratory session were analyzed by a two-sample t-test. A questionnaire evaluating the effectiveness of both models was given to faculty members and students who participated in both laboratory sessions. These results were analyzed by paired t-test.

RESULTS

Participation in the laboratory sessions did not significantly impact the final exam scores (p = 0.722). Students who had better didactic performance in the course performed better in the final exam, irrespective of laboratory participation. Both students and faculty members preferred typodont to the pig mandibles in learning or teaching periodontal surgical concepts, but both felt gaining flap management and flap refection experience to be better with the pig mandible model without statistical significance (p = 0.119 and p = 0.070, respectively).

CONCLUSION

Within the limitations of this study, we can conclude that laboratory sessions did not significantly improve student performance on the exam. Students and faculty members generally gave positive feedback on both instructional models. Periodontal typodont could be an alternative model for teaching dental students, periodontal surgical concepts.

A Sex-Specific Evaluation of Dental Students' Ability to Perform Subgingival Debridement: Randomized Trial

BACKGROUND

A successful periodontitis treatment demands good manual skills. A correlation between biological sex and dental students' manual dexterity is currently unknown.

OBJECTIVE

This study examines performance differences between male and female students within subgingival debridement.

METHODS

A total of 75 third-year dental students were divided by biological sex (male/female) and randomly assigned to one of two work methods (manual curettes n=38; power-driven instruments n=37). Students were trained on periodontitis models for 25 minutes daily over 10 days using the assigned manual or power-driven instrument. Practical training included subgingival debridement of all tooth types on phantom heads. Practical exams were performed after the training session (T1) and after 6 months (T2), and comprised subgingival debridement of four teeth within 20 minutes. The percentage of debrided root surface was assessed and statistically analyzed using a linear mixed-effects regression model (P<.05).

RESULTS

The analysis is based on 68 students (both groups n=34). The percentage of cleaned surfaces was not significantly different (P=.40) between male (mean 81.6%, SD 18.2%) and female (mean 76.3%, SD 21.1%) students, irrespective of the instrument used. The use of power-driven instruments (mean 81.3%, SD 20.5%) led to significantly better results than the use of manual curettes (mean 75.4%, SD 19.4%; P=.02), and the overall performance decreased over time (T1: mean 84.5%, SD 17.5%; T2: mean 72.3%, SD 20.8%; P<.001).

CONCLUSIONS

Female and male students performed equally well in subgingival debridement. Therefore, sex-differentiated teaching methods are not necessary.

Assessment of a developed pig cadaver model for teaching crown lengthening surgical procedures

Background

Information regarding using a pig cadaver model for teaching purposes in dentistry is limited, especially for periodontal surgery procedures. The aim of this study was to assess the feasibility and efficacy of teaching crown lengthening surgical procedures using a prepared pig cadaver model.

Methods

Mandibles of slaughtered pigs with subgingival crown fracture defects on two premolars and two molars on each side were prepared as periodontal surgery teaching cases. A resident group (n = 20) and an instructor group (n = 18) participated in assessing the efficacy of the model by completing questionnaires before and after training sessions. Data was either assessed descriptively or analyzed statistically with Wilcoxon signed-rank test with the significance level at α = 0.05.

Results

Results revealed that all the knowledge points showed statistically significant improvements (p < 0.05) except for the procedure to determine the quantity of bone removal during osteotomy procedures. Most residents rated the efficacy of the model obtained with 9.0 out of 10 scale. The data of effectiveness of the pig cadaver model from the instructor group ranged from 7.4 ± 1.4 to 9.0 ± 1.0.

Conclusion

Results of this study support feasibility in using prepared pig cadaver models to teach crown lengthening surgical procedures to postgraduates.

Comparison of the effects of different instrumentation techniques on root surface roughness and cement loss using micro-computerized tomography: An in-vitro study

OBJECTIVES

The purpose of this study was to compare the effectiveness of three different instruments on the cement loss and roughness of the root surface following scaling and root planning (SRP) using micro-computerized tomography (micro-CT).

METHODS

In this experimental study, 60 single-rooted extracted human teeth were used and divided into three groups. All teeth were scanned with micro-CT before and after SRP. Group 1: SRP was performed by Gracey-curette, Group 2: SRP was performed by using an ultrasonic device and Group 3: SRP was performed by using a piezo ultrasonic device. Cement loss and porosity of the root surface were analysed by micro-computerized tomography, which is a current imaging technique that provides high-quality images and allows for qualitative and quantitative analysis of samples.

RESULTS

Results of our study revealed that initial porosity values were 1.60%, 1.25%, 1.59% for the group 1, 2, 3, and 0.93%, 0.86 and 0.80 after SRP respectively. Although Group 3 had the least surface roughness, there was no statistically significant difference between the groups. Cement loss following SRP was 47.15 μmin the piezo ultrasonic device group, 59.44 µm in the ultrasonic device, and 134.163 µm in the Gracey-curette group respectively. The highest cement loss was seen in the Gracey-curette group, and there was a significant difference between the three groups.

CONCLUSIONS

In conclusion, it was observed that surface roughness decreased and similar surface roughness was obtained with all three methods, but more cementum loss was observed with Gracey-curette. Therefore, ultrasonic devices appear to be a viable alternative to manual instrumentation with curettes.

Influence of motivation and a new digitized training program on undergraduate dental students during preclinical scaling training

BACKGROUND

The current study evaluated whether a new digitized scaling training program (DTP: n = 30; supervisor-student-ratio 1:10) improves the performance of undergraduate dental student during a preclinical course in regard to two different instruments [sonic scalers (AIR) and Gracey curettes (GRA)] compared to a conventional training program (CTP: n = 19; supervisor-student-ratio 1:4).

METHODS

All the participants received a two-hour lecture on both instruments, followed by a 12-week period with a weekly training program lasting 45 min (10 sessions); one group was supported by DTP. At the end of the training phase, all the participants performed the subgingival scaling of six equivalent test teeth using GRA and AIR. Treatment time, proportion of removed simulated biofilm (relative cleaning efficacy, RCE-b) and hard deposits (RCE-d) were recorded. By using a pseudonymized questionnaire with a 5-point Likert scale, self-assessment of scaling effort, handling, root surface roughness/destruction and effectiveness were evaluated. In addition, personal data such as age, gender, handedness, regularity of playing computer games/consoles and previous dental/technical or medical education were elevated and correlated with cleaning efficacy.

RESULTS

The DTP participants showed higher effectiveness in RCE-b compared to those who used the CTP with GRA (71.54% vs. 67.23%, p = 0.004) and AIR (71.75% vs. 62.63%, p ≤ 0.001), and the DTP students were faster with both instruments (p ≤ 0.001). For RCE-d, there was no significant difference between the DTP and CTP groups (GRA p = 0.471; AIR p = 0.158), whereas DTP showed better RCE-d results with GRA versus AIR (84.68% vs. 77.85%, p < 0.001). According to the questionnaire, no significant differences were detected between the training groups in terms of self-assessment, handling, treatment time, root surface roughness/destruction or effectiveness of the instruments. The CTP group favored AIR compared to GRA regarding the fatigue effect. The CTP and playing computer games/consoles regularly was correlated with lower RCE-b, whereas previous education in medicine/dentistry was correlated with higher RCE-b values.

CONCLUSIONS

Within the limitations of the study, the DTP with a reduced supervision effort compared to the CTP resulted in higher effectiveness and lower instrumentation time for removing simulated biofilms.

Evaluation of a systematic digitized training program on the effectivity of subgingival instrumentation with curettes and sonic scalers in vitro

Objectives

Whereas the key role of subgingival instrumentation in periodontal therapy is well known, the influence of operators’ experience/training with different devices on treatment results is yet uncertain. Therefore, we assessed untrained undergraduate students, working on manikins, as to how effectively they learn to use curettes (GRA) and sonic scalers (AIR); hypothesizing that AIR will result in higher relative cleaning efficacy (RCE) than GRA.

Material and methods

Before baseline evaluation (T0), 30 operators (9 males, 21 females) received a 2-h theoretical lesson for both instruments, followed by a 12-week period with a weekly digitized training program for 45 min. During three sessions (T1–T3), the operators had to instrument six equivalent test teeth with GRA and AIR. At T0–T3, treatment time, proportion of removed simulated biofilm (RCE-b), and hard deposits (RCE-d) were measured.

Results

At T0, RCE-b was in mean(SD) 64.18(25.74) % for GRA, 62.25(26.69) % for AIR; (p = 0.172) and RCE-d 85.48(12.32) %/ 65.71(15.27) % (p < 0.001). At T3, operators reached highest RCE-b in both groups (GRA/AIR 71.54(23.90) %/71.75(23.05)%; p = 0.864); RCE-d GRA/AIR: 84.68(16.84) %/77.85(13.98) %; p < 0.001). Both groups achieved shorter treatment times after training. At T3, using curettes was faster (GRA/AIR 16.67(3.31) min/19.80(4.52) min; p < 0.001).

Conclusions

After systematic digitized training, untrained operators were able to clean 70% of the root surfaces with curettes and sonic scalers.

Clinical relevance

It can be concluded that a systematic digitized and interactive training program in manikin heads is helpful in the training of root surface debridement.

Calculus Removal and Root Surface Roughness When Using the Er:YAG or Er,Cr:YSGG Laser Compared with Conventional Instrumentation Method: A Literature Review

Objective: The purpose of this literature review was to evaluate the effectiveness of using Er:YAG (erbium-doped yttrium/aluminum/garnet) laser or Er,Cr:YSGG (erbium, chromium-doped yttrium/scandium/gallium/garnet) laser on calculus removal and their effect on the topography and roughness of root surface in comparison with the conventional instruments in the nonsurgical periodontal therapy. Background data: One of the most challenging problems in treatment of periodontal disease is the elimination of plaque and calculus, leaving a clean and smooth root surface to decrease plaque and calculus retention, and for good gingival reattachment. Materials and methods: PubMed and Google Scholar were searched for available literature. The electronic search was limited to articles published in the period between January 2007 and April 2017, in the English language. Results: A total of 47 publications fulfilled the inclusion criteria of this systematic review and screened according to the research questions. Calculus removal using the ultrasonic instrument showed remaining calculus compared with the hand instrument, whereas, on the contrary, erbium lasers revealed no remaining calculus or smaller amounts compared with the conventional instruments when used in appropriate settings. The results of this review showed that ultrasonic instrumentation produced effects on the root surface almost similar to that of hand instrumentation. Er:YAG laser and Er,Cr:YSGG laser clarify a little more surface roughness when compared with conventional instruments. Conclusions: The present systematic review indicates that a combination of scaling and root planing (SRP) using the erbium lasers as an adjunctive therapy at certain parameters can be appropriate to remove residual debris from the root surface and at the same time have little or no negative thermal effect on the root surface. The Er:YAG laser also seems to be the most suitable for nonsurgical periodontal therapy. Additional new good-designed studies are needed to evaluate the effectiveness of erbium lasers with SRP in nonsurgical periodontal therapy.

Faculty calibration and students' self-assessments using an instructional rubric in preparation for a practical examination

PURPOSE

The purpose of this study was to investigate the effect of faculty calibration and students' self-assessments on students' performances in a periodontal practical examination.

METHODS

Before a new instructional rubric was implemented in the second-year periodontics course, faculty calibration was conducted with a pilot group of 32 third-year dental students. Afterwards, the new rubric was implemented in the second-year periodontics course. Second-year students used the rubric for their self-assessments before the practical examination. An intraclass correlation coefficient was used to test the reliability of the faculty members. A paired t test was used to compare scores between self-assessments of the pilot group (third-year students) and faculty evaluation. A two-way analysis of variance was performed to compare scores between self-assessments of second-year students and faculty evaluations. Chi-square tests were used to compare overall failure rates amongst four different classes.

RESULTS

The reliability amongst the faculty members was strong (the ICC = 0.75 at the first and 0.97 at the second calibration). The mean self-assessment score from the pilot group was significantly higher than the faculty evaluation. However, the mean self-assessment score of second-year students was significantly lower than the faculty evaluation. The class that practiced self-assessments with the validated instructional rubric exhibited the lowest overall failure rate compared to three past classes.

CONCLUSIONS

Using an instructional rubric and conducting faculty calibration improved the process of the periodontal practical examination. Improving the examination process and practicing self-assessments with feedback from faculty may have a positive impact on students' performances in the examination.

Removal of simulated biofilm: an evaluation of the effect on root surfaces roughness after scaling

BACKGROUND

Despite the development of less invasive devices, a debate exists about the benefits and risks of hand versus powered root surface instrumentation used in supportive periodontal therapy (SPT). The aim of the in vitro study was to differentially compare plaque removal efficacy and root surface roughening of newly developed sonic, ultrasonic scaler, and curettes in the hands of experienced versus less experienced operators.

MATERIALS AND METHODS

Sonic (AIR), ultrasonic devices (TIG), and double-gracey curettes (GRA) were utilized by seven experienced (EO) and four less experienced operators (LO) for root surface instrumentation of standardized plastic teeth on manikins' heads in a randomized sequence. The proportion of residual simulated plaque (RSP area in %) was planimetrically assessed, and the average root surface roughness produced (Ra and ∆Ra in μm) was measured by a precision profilometer.

RESULTS

The uninstrumented root surfaces showed a Ra of (median (Q25/Q75)) 1.00 μm (0.83/1.16). Following instrumentation, EO left significantly less RSP than LO regardless of the used instruments (20.00 % (10.00/34.00) vs. 26.00 % (12.00/44.00) p < 0.001), whereas the ∆Ra values (0.29 μm (-0.04/0.96) vs. 0.35 μm (-0.04/1.01), p = 0.237) failed to show significant differences. The surface roughness was higher with GRA followed by AIR then TIG regardless of operators' experience (p < 0.001).

CONCLUSION

Within the limits of the present study, the sonic device was most efficient in plaque removal, while the ultrasonic device produced the least surface roughness.

CLINICAL RELEVANCE

All three tested instruments seem effective in the mechanical root debridement during SPT, whereat the ultrasonic device show the smoothest root surface of all.

Removal of simulated biofilm: a preclinical ergonomic comparison of instruments and operators

BACKGROUND

Periodontal scaling might cause musculoskeletal disorders, and scaling instruments might not only have different effectiveness and efficiency but also differ in their ergonomic properties. The present study assessed ergonomic working patterns of experienced (EO) and less experienced operators (LO) when using hand and powered devices for periodontal scaling and root planning.

METHODS

In an experimental study using periodontally affected manikins, sonic (AIR), ultrasonic (TIG) and hand instruments (GRA) were used by 11 operators (7 EO/4 LO) during simulated supportive periodontal therapy. Using an electronic motion monitoring system, we objectively assessed the working frequency and positioning of hand, neck and head. Operators' subjective evaluation of the instruments was recorded using a questionnaire.

RESULTS

Hand instruments were used with the lowest frequency (2.57 ± 1.08 s(-1)) but greatest wrist deviation (59.57 ± 53.94°). EO used instruments more specifically than LO, and generally worked more ergonomically, with less inclination of head and neck in both the frontal and sagittal planes, especially when using hand instruments. All groups found hand instruments more tiring and difficult to use than powered instruments.

CONCLUSION

Regardless of operators' experience, powered instruments were used more ergonomically and were subjectively preferred compared to hand instruments.

CLINICAL RELEVANCE

The use of hand instruments has potential ergonomic disadvantages. However, with increasing experience, operators are able to recognise and mitigate possible risks.

Subgingival instrumentation to remove simulated plaque in vitro: influence of operators' experience and type of instrument

BACKGROUND

There is uncertainty regarding the benefits and risks of hand versus powered root surface instrumentation. Moreover, the influence of operators' experience on treatment results is unclear. We compared newly developed sonic, ultrasonic and hand instruments, hypothesizing that powered devices allow to remove more simulated plaque in less time than hand instruments, with significant influence of operators' experience.

METHODS

Sonic scaler (AIR), ultrasonic scaler (TIG) device and double Gracey curettes (GRA) were utilized by seven experienced operators (EOs) and four less experienced operators (LOs) in periodontitis manikin heads. The time required for treatment, the proportion of residual-simulated plaque and the weight loss caused by scaling as a proxy for root surface destruction were measured.

RESULTS

Using different instruments led to significantly different proportions of removed simulated plaque regardless of operators' experience (AIR, 80.2 ± 21.3 %, TIG, 69.9 ± 22.5 %, GRA, 73.1 ± 20.0 %) (p < 0.001). Treatment times did not significantly differ between EO and LO (p > 0.05). Weight loss was increased when using hand instead of powered instruments (p < 0.001), with significantly higher weight loss induced by LO than EO (p = 0.004).

CONCLUSION

Within the present study, EO did not remove more simulated plaque in less time but induced less root surface destruction. Using a sonic device was most beneficial for plaque removal.

CLINICAL RELEVANCE

Successful root surface debridement requires both time and training regardless of the used instrument. Hand instruments might cause more damage to root surfaces, especially in the hands of less experienced operators.

Retention of questionable and hopeless teeth in compliant patients treated for aggressive periodontitis

AIM

The aim of this study was to determine the survival rates of questionable and hopeless teeth in patients with aggressive periodontitis (AgP) and chronic periodontitis (CP) during 15 years of supportive periodontal therapy (SPT).

MATERIALS AND METHODS

Thirty-four AgP and 34 CP patients (SPT≥10 years) with bone loss of ≥50% at ≥2 teeth were consecutively recruited. Bone loss was measured on digitized radiographs and teeth were categorized as "questionable" (≥50 to <70% bone loss) or as "hopeless" (≥70%). Progression in pocket probing depths (PPD) during SPT, tooth loss and reasons for extraction were analysed.

RESULTS

In AgP patients, 262 teeth were considered as questionable and 63 as hopeless (CP: 149/51). During active periodontal therapy, 25 questionable and 26 hopeless teeth were extracted (CP: 12/16). During 15.3 ± 4.1 years of SPT of AgP 28 questionable and 15 hopeless teeth were removed (CP: 28/12). The mean tooth loss per patient during SPT in total was 0.14 (AgP) and 0.16 (CP) teeth/year. There were no significant differences in tooth loss or longitudinal progression of PPD between AgP and CP patients.

CONCLUSIONS

In patients with AgP, 88.2% (209 of 237) of questionable and 59.5% (22 of 37) of hopeless teeth survived 15 years during regular SPT in a dental school department.

Innovative educational methods and technologies applicable to continuing professional development in periodontology

Continuous professional development (CPD) in Periodontology refers to the overall framework of opportunities that facilitate a life-long learning practice, driven by the learner-practitioner and supported by a variety of institutions and individuals. CPD must address different needs for a great diversity of practitioners. It is clear that no particular methodology or technology is able to successfully accommodate the entire spectrum of CPD in Periodontology. Course designers must choose from and combine a wide array of methodologies and technologies, depending upon the needs of the learners and the objectives of the intended education. Research suggests that 'interactivity', 'flexibility', 'continuity' and 'relevance to learners' practice' are major characteristics of successful CPD. Various methods of mentoring, peer-learning environments and work-based learning have been combined with reflective practice and self-study to form the methodological backbone of CPD courses. Blended learning encompasses a wide array of technologies and methodologies and has been successfully used in CPD courses. Internet-based content learning management systems, portable Internet devices, powerful databases and search engines, together with initiatives such as 'open access' and 'open courseware' provide an array of effective instructional and communication tools. Assessment remains a key issue in CPD, providing learners with valuable feedback and it ensures the credibility and effectiveness of the learning process. Assessment is a multi-level process using different methods for different learning outcomes, as directed by current evidence and best practices. Finally, quality assurance of the education provided must follow CPD courses at all times through a structured and credible process.

Clinical effects after subgingival polishing with a non-aggressive ultrasonic device in initial therapy

OBJECTIVES

The Vector ultrasonic system provides root debridement supported by different abrasive irrigation fluids. The aim of this study was to investigate the clinical outcome of initial therapy with subgingival low-abrasive debridement.

MATERIAL AND METHODS

Twenty patients, who had at least two teeth with pocket depths >5 mm in each quadrant, took part in this prospective randomized clinical study. Patients were treated in a split-mouth design as one test quadrant (1) subgingivally with Vector fluid polish (VU-H) and as three control quadrants, (2) with only supragingival polishing (PO-H), (3) with hand instruments (HI-H) performed by a hygienist and (4) with hand instruments (HI-D) performed by a dentist. At baseline, 3 and 6 months after treatment, pocket depths and attachment levels (ALs) were measured and bleeding on probing (BOP) was recorded.

RESULTS

At 6-month evaluation, all groups showed an improvement in clinical parameters. No statistically significant differences in any of the investigated parameters could be observed between the Vector group and the hand scaling groups, or when comparing the results of the two different operators.

CONCLUSION

This study demonstrates that Vector treatment with polishing fluid was able to reduce pocket depths and the prevalence of BOP and improve clinical AL in a similar way as scaling with curettes.

Effect of handedness on learning subgingival scaling with curettes: a study on manikins

The aim of the present study was to evaluate the influence of systematic manikin-head training and the effectiveness of subgingival scaling applied with hand instruments (curettes) by right- and left-handed dental students on dental chairs (traditional) designed for right-handers. A questionnaire focusing on handedness was administered to 69 voluntary dental students in the third class at the School of Dentistry during pre-participation examination. Handedness was assessed using the Turkish version of the Edinburgh Handedness Inventory. Then, 18 dental students were specially selected in 2 equal groups according to hand preference: consistent right-handers with Geschwind Scores of +100 (5 female and 4 male) and consistent left-handers with Geschwind Scores of -100 (5 female and 4 male). These two untrained dental student groups received 10 weeks manikin-head training. Subgingival scaling was performed with hand instruments (Gracey curettes) in manikin-head mounted on right-sided dental chairs. At 6 test days each dental student had to instrument 12 test teeth. Effectiveness of subgingival scaling was evaluated by adoption of a grading system. This system had scores from 0 to 3 and was defined by illustrated and described criteria. Statistical analysis was carried out with SPSS. Two groups were statistically compared on all test days. The yet-untrained left-handed dental students begin with a relatively high the mean score of 2.25, compared to the yet-trained right-handed dental students with 1.93, which was statistically significant (p > .05). The right-handed dental students reached the mean score of 0.53, whereas the left-handed dental students reached the mean score of 0.87 on test day 6. Significant differences in the mean scores were found between the two groups for overall surfaces (p < .05), the distal surfaces (p < .01), lingual surfaces (p < .01), and each group of teeth (p < .05). But there was no statistically significant difference between the 2 groups of students on all test day, except for test day 3 in terms of the mean scores for the facial and mesial surfaces (p > .05). Learning success was observed a high level in both groups through systematical training (p < .0001). The present study has documented that the left-handed dental students were less successful than the right-handed dental students in subgingival scaling, except for mesial and facial surfaces. However although training on right-sided chairs, they were quite similar to their right-handed counterparts in terms of learning success.

A sheep cadaver model for demonstration and training periodontal surgical methods

There is lack of data on the suitability of animal cadaver models for teaching purposes in dentistry. Here, we describe a model suitable for training for several periodontal surgical methods. Mandibles of freshly slaughtered Australian adult sheep and lambs were examined. Periodontal probing depths (PPDs) were measured at six sites of every tooth present. The following surgical techniques were critically analyzed: access flap with interrupted, continuous sutures; apically repositioned flap with periosteal sutures; coronally advanced flap with sling suture; gingivectomy; and distal wedge procedure. Probing depths were highest in the buccal furcation area of 1st and 2nd molars, where deep intrabony lesions were present in certain samples from adult sheep. Another area of increased probing depth was lingual to canines and incisors. Here, a pronounced lower dental pad of fibrous tissue was present. In this area, gingivectomy could always be accomplished. Fibrous tissue was also found distal to the most posterior molar, where the distal wedge procedure could be exercised. Access flaps and apically repositioned flaps could be performed particularly at premolars. Here, interrupted or continuous sutures were possible. Because of tight interdental contact areas, needle insertion was difficult at molars. After periosteal dissection, labial flaps at anterior teeth could easily be advanced coronally and sutured with sling sutures. Because of the teeth's dimensions and tight contact areas, simulation of more advanced techniques such as papilla preservation flaps was not possible. The sheep mandible seems to be a feasible training model for the demonstration and exercise of various periodontal surgical techniques for the treatment of periodontitis.

Learning root debridement with curettes and power-driven instruments. Part II: Clinical results following mechanical, nonsurgical therapy

BACKGROUND, AIMS

In a manikin study we recently assessed how effectively student operators were able to learn scaling with curettes (GRA) and power-driven instruments (PP). Calculating the debrided root area effectiveness was low in both groups without systematic training or without a motivational program. After 10 weeks (20 h) of training, operators reached a high effectiveness of 84.7% (GRA) and 81.6% (PP). The purpose of the present study was to evaluate the clinical outcome of nonsurgical treatment as performed by these student operators.

METHODS

In a clinical trial, 19 students trained in the use of Gracey curettes for 10 weeks (=20 h) (GRA10) and Periopolisher system for 1 week (=2 h) (PP1), and 20 students trained in the use of Gracey curettes for 1 week (GRA1) and the Periopolisher for 10 weeks (PP10) treated one patient each in a split-mouth design. At baseline and 6 months, we recorded probing depth (PD), probing attachment level (PAL) and bleeding on probing (BOP) by computer-assisted probing. Statistical analysis was carried out for moderate (category B) and deep sites (category C). Groups were compared using Student's t-tests (p<0.05).

RESULTS

Category B sites showed a PD reduction of 1.2/1.0 mm (GRA10/GRA1) and 1.1 mm (PP10/PP1). PAL gain was 0.5/0.3 mm (GRA10/GRA1) and 0.4/0.2 mm (PP10/PP1). In category C sites, PD reduction was 2.1/2.3 mm (GRA10/GRA1) and 2.0 mm (PP10/PP1) with a PAL gain of 0.6/0.9 mm (GRA10/GRA1) and 0.4 mm (PP10/PP1). BOP was significantly lower in all groups.

CONCLUSION

The results show that student operators who had received a systematical training on manikins and had attained different effectiveness results were able to treat periodontally diseased patients successfully using both Gracey and Periopolisher instruments.

Learning root debridement with curettes and power-driven instruments. Part I: a training program to increase effectivity

BACKGROUND/AIMS

In a dummy-head trial, we assessed how effectively untrained operators were able to learn scaling with curettes and power-driven instruments.

METHODS

Two untrained operator groups (n = 11 each) received six 2-h lessons during a 10-week period following a training program. Subgingival scaling was performed with curettes (GRA) and a power-driven system (PP). At 6 test days each subject had to instrument 10 test teeth. The percentage of debrided area was assessed with an image analysis program. Learning success was measured as a percentage of debrided root area and scaling time. Furthermore, the effectivity was related to difficulty in anatomical situations and access to root surfaces. Statistical analysis was carried out with SPSS.

RESULTS

At baseline, effectivity was 63.1% (GRA) vs. 52.3% (PP). Between weeks 9 and 11, operators reached a plateau for group GRA at 84.7% and group PP at 81.3%. Scaling time did not differ between the two groups. Debridement of teeth with complex root shapes that were hard to access was less effective with the power-driven system.

CONCLUSION

Independent of the instrument used, untrained operators were only able to debride root surfaces at low levels of efficacy. With systematical training, effective scaling with the power- driven system was as easy to learn as with hand instruments. On root surfaces with complicated shape and anatomy or difficult accessibility, the power-driven system works significantly less effectively.