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

New design of interdental rubber picks - does the archimedean screw design bring an improvement for experimental cleaning efficacy and force?

BACKGROUND

Up to date, interdental brushes (IDB) are the first choice for interdental cleaning because of their cleaning efficacy. Cylindrical ones must be selected individually according to the size/morphology of the interdental area (IDR), whereas conical ones cover a larger variability of IDR. However, there is a trend on the part of patients towards interdental rubber picks (IRP) which are in general conically shaped, and which seem to be linked with lower cleaning efficacy. A new IRP with an Archimedes´ screw design was developed to overcome this limitation. Therefore, the in vitro study aimed to measure the experimental cleaning efficacy (ECE) and force (ECF) during interdental use of IDBs versus the new IRP type.

METHODS

Three IRPs with different tapers (PHB angled: 0.039, PHB straight S: 0.027, Vitis straight M: 0.045; all Flexipicks, Dentaid, Cerdanyola del Vallès, Spain) were compared to one IDB (Interprox micro PHD 0.9, Dentaid, Cerdanyola del Vallès, Spain). IDR were reproduced by a 3D-printer (Form2, Formlabs Sommerville, MA, USA) according to human teeth and matched to equivalent pairs (isosceles triangle, concave, convex) in three different diameters (1.0 mm,1.1 mm,1.3 mm). Covered with simulated biofilm, pre-/ post-brushing situations of IDR (standardized, computer-aided ten cycles) were photographed and quantified by digital image subtraction to calculate ECE [%]. ECF were registered with a load cell [N]. Statistically significant differences were detected using the Mann-Whitney-U-test and the Kruskal-Wallis-test with Bonferroni correction for multiple testing.

RESULTS

Overall, the ECE (mean ± SD) was higher for IDB micro 0.9 (45.95 ± 11.34%, p < 0.001) compared to all IRPs (PHB angled: 25.37 ± 15.29%; PHB straight: 22.28 ± 16.75%; Vitis straight: 25.24 ± 12.21%; p ≤ 0.001), whereat best ECE was achieved in isosceles triangle IDR of 1.0-1.1 mm (IDB micro 0.9: 70.7 ± 7.7%; PHB angled S: 57.30 ± 4.43%; p < 0.001). The highest ECF occurred for Vitis straight M with 2.11 ± 0.46 N, while IDB micro 0.9 showed lowest ECF values (0.64 ± 0.14 N; p < 0.001).

CONCLUSIONS

IRP with an Archimedes´ screw design and a higher taper were associated with advanced ECE but also higher ECF, nevertheless, ECE didn't reach the cleaning efficacy of conventional IDBs.

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.

Results of an experimental study of subgingival cleaning effectiveness in the furcation area

BACKGROUND

Sufficient biofilm removal in the furcation area (FA) is a major challenge in the clinical practice of supportive periodontal therapy. The aim of the present experimental study was to simulate subgingival cleaning of the FA using a powered scaler (sonic scaler (AIR), ultrasonic scaler (US)) for conventional mechanical debridement versus two air polishing with nonabrasive powder (LAPA-1: glycine powder, LAPA-2: erythritol powder) and different nozzles for supra-/subgingival cleaning for each device.

METHODS

Seven trained and calibrated operators with ≥ 2 years each of professional experience in treating periodontitis used the instruments to clean 3D-printed replicas of six molars with through-and-through FA (four 3-rooted and two 2-rooted teeth) in a manikin head. AIR and US were used in the control group; air polishing instruments were used in the test group. For reproducible evaluation, the test teeth were separated vertically into two or three parts, illuminated with ultraviolet light, photographed and evaluated planimetrically. Treatment time (TrT, in s) and relative cleaning efficacy (RCE, in %) were measured.

RESULTS

Overall, 3-rooted molars (RCE in the entire FA, 23.19 ± 20.98%) could be cleaned significantly less effectively than 2-rooted molars (53.04 ± 28.45%, p < 0.001), regardless of the instrument used. In the cleaning of the entire FA, significantly higher RCE values were achieved with conventional mechanical debridement (AIR/US: 46.04 ± 25.96%/39.63 ± 22.02%; AIR vs. US: p > 0.05) than with air polishing (LAPA-1/LAPA-2: 34.06 ± 29.48%/17.09 ± 18.85%; LAPA-1 vs. LAPA-2: p < 0.001) regardless of whether a supra- or subgingival cleaning nozzle used (p < 0.001). Only LAPA-1 with a subgingival nozzle showed RCE values comparable to those of US (41.07 ± 28.95% vs. 39.63 ± 22.02%, p > 0.05). TrT was longest for US (299.40 ± 120.69 s) and shortest for LAPA-1 with a supragingival nozzle (129.67 ± 60.92 s, p < 0.001).

CONCLUSIONS

All of the examined instruments were effective to some degree in removing the simulated biofilm from the FA, but they differed substantially in cleaning efficacy. Only one air polishing device (LAPA-1) with a rigid subgingival nozzle was able to achieve RCE values similar to those of US. The current investigation confirmed that conventional mechanical debridement with powered scalers were most effective, but treatment took longer with these devices than air polishing.

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.

How to train periodontal endoscopy? Results of a pilot study removing simulated hard deposits in vitro

OBJECTIVES

There is uncertainty regarding the benefits of periodontal endoscopy (PE) for subgingival instrumentation. Moreover, the influence of operators' experience and training with such a device on treatment results is unclear. Therefore, we compared in an in vitro study the use of PE for scaling and root planing (SRP) with the conventional non-surgical therapy, hypothesizing that using a PE allows to remove more simulated hard deposits than without (nPE), influenced by the operators' experience and training.

MATERIAL AND METHODS

A sonic device and Gracey curettes were utilized by 11 operators (six dentists, five dental hygienists) in periodontitis manikins heads. The time required for treatment and the proportion of removed simulated hard deposits by SRP were measured.

RESULTS

Using the PE led to a significant difference in removal of simulated hard deposits (%) (mean ± SD) irrespective of operators' experience (PE 90.78 ± 12.10% (range 58.80-100%); nPE 79.98 ± 22.15% (range 38.10-100%, p < 0.001)), sub-analyses for different tooth types demonstrated a significant difference in favor of PE for front teeth (p < 0.001) and in the upper jaw independent of the tooth type (p < 0.001). Comparison of treatment times for two quadrants with and without PE showed a significantly longer treatment time with PE (∆22.27 ± 17.98 mins, p <0.001).

CONCLUSIONS

Within the present pilot study, the use of PE led to more removal of simulated hard deposits but was concomitantly related to more time and financial effort. Using PE was most beneficial in the front area.

CLINICAL RELEVANCE

PE may provide additional benefits for the removal of hard deposits compared to traditional SRP. The beneficial effect of PE seems not to be influenced by operators experience nor by pocket probing depth.

Scanning Electron Microscopy Evaluation of Root Surfaces After Instrumentation With Two Piezoelectric Devices

Scanning electron microscopy evaluation of root surfaces after ultrasonic instrumentation was performed with 2 different metallic tips on piezoelectric devices. Fresh extracted teeth were collected for experimental observation and randomly divided into 2 groups: Test Group, where the root surfaces were treated using an iron, rough, double nano-structural coated (T-Black), corindone-treated tip, and Control Group where the root surfaces were treated with a conventional iron smooth tip. A scanning electronic microscope analysis was performed and the surface roughness and the amount of residual debris were evaluated. Descriptive and inferential statistics were performed. Twenty specimens were analyzed, 10 per group and a total of 21.4 × 10 μm has been observed. On treated area percentage of debris after ultrasonic scaling in Test Group was 1.9 ± 1.8%, while in Control Group it was 5.7 ± 4.3%. Within the limits of the study, it seems that the efficacy of the novel iron, rough, double nano-structural coated (T-Black), corindone-treated structure tip showed greater performance in terms of root surface debridement than the conventional iron smooth tip. The possibility to use a single tool (ultrasonic device with a specific tip) for the root planing procedure within the nonsurgical mechanical therapy may represent a significant advantage for the clinicians. The tested novel tip seems to be able to show the requested ideal characteristics. However, further clinical studies are needed to demonstrate the in vitro results.

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.