Position paper: sonic and ultrasonic scalers in periodontics. Research, Science and Therapy Committee of the American Academy of Periodontology

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.

Subgingival air polishing with trehalose powder during supportive periodontal therapy: use of a conical shaped tip during a randomized clinical trial

Background

This study investigated clinical parameters using a new air-polishing device compared to sonic scaling for subgingival biofilm removal during supportive periodontal therapy. The aim was to evaluate noninferiority of air-polishing compared to sonic scaling in deeper periodontal pockets with respect to pocket depth (PD).

Methods

In 44 participants, 2 single-rooted teeth [(PD) ≥ 5 mm] were treated using a split-mouth design. While a new air polishing device with a conical shaped tip was used for the experimental group, sonic scaling was performed in the control group. PD, clinical attachment level (CAL), and bleeding on probing (BOP) were recorded at baseline, (T0) after 3 months (T1) and 6 months (T2). Pain perception was rated using a visual analog scale (VAS; 0 = no pain, 100 = maximum pain).

Results

PD and CAL decreased significantly for both groups, while no intergroup differences were found (PD [mean, mm] control T0 5.96, T2 4.75; experimental T0 5.96, T2 4.8; intergroup p = 0.998; CAL [mean, mm] control T0 7.38, T2 5.84; experimental T0 7.28, T2 6.34; intergroup p = 0.368). For BOP, no intergroup differences were found from T0 to T2 (reduction control 42.5%; experimental 46.5% p = 0.398). Pain perception was significantly lower for air polishing (VAS [mean, mm] control 28.8, experimental 12.56; p = 0.006).

Conclusion

None of the two treatment procedures showed inferior clinical effects with regard to PD, CAL and BOP with air polishing being more comfortable to patients.

Trial registration The study was registered in an international trial register on August 14/08/2019, before the start of recruitment (German Clinical Trial Register number DRKS00017844).

Effect of prophylactic instrumentation on surface roughness of tooth-colored restorative material: An in vitro study

Aim:

To compare and evaluate the surface characteristics of different restorative materials used for restoration of cervical defects when subjected to periodontal prophylactic instrumentation techniques.

Materials and Methodology:

Sixty box-shaped cavities were prepared on the labial surface of decoronated permanent maxillary anterior teeth which were randomly divided into two groups (n = 30) based on the instrumentation technique Group I: Manual instrumentation using curettes and Group II: Ultrasonic instrumentation. The samples were further divided into three subgroups based on restorative material subgroups I V and II V-restored with Vitremer, subgroups I F and II F-restored with Filtek Z 250 XT and subgroups I D and II D-restored with Dyract flow, respectively. After finishing and polishing, the samples were subjected to surface profilometry analysis for determining the surface roughness values (Ra). Thereafter, the restored surfaces of all the samples in different subgroups were subjected to prophylactic instrumentation with Gracey's curettes (Group I) and ultrasonic scalers (Group II). Ra values were recorded again after prophylactic instrumentation and after polishing. The data thus obtained were subjected to the statistical analysis using the independent t-test and one-way ANOVA (p<0.05).

Results:

Ra values were significantly higher for both manual and ultrasonic prophylaxis compared to preprophylaxis and postpolishing in all the three restorative materials. Ultrasonic scaling produced significantly higher Ra for subgroup V as compared to subgroup F and subgroup D, whereas the difference between the materials was not significant for manual scaling.

Conclusion:

Manual prophylaxis resulted in significant reduction in surface roughness of all the three restorative materials while ultrasonic prophylaxis resulted in significant reduction for Vitremer only. Polishing after scaling significantly reduced the effect of both manual and ultrasonic prophylaxis on surface roughness.

A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips

Strategies to return to dental practice in pandemic times is a new challenge due to the generation and spread of potentially contaminated dispersion particles (PCDP) that may contain the SARS-CoV-2, the etiological factor of the COVID-19 disease. Due to the significant dispersion of PCDP in the dental environment, the use of equipment such as ultrasonic tips have been inadvisable during the pandemic. Several clinical procedures, however, benefit from the use of such equipment. Thus, using a microbial dispersion model of PCDP, the aim of this study was to compare the dispersion caused by the dental drill (DD) an ultrasonic tip (UT) alone and the UT coupled with a Spray control (SC) device. The DD, UT (with or without the SC) were activated for one minute having had the water from the reservoir replaced with a suspension of Lactobacillus casei Shirota (1.5 x 10⁸ CFU/mL). Petri dishes containing MRS agar were positioned at 50cm, 100cm and 150cm from the headrest of the dental chair at different angles (0 degree and 90 degrees). At 50 cm, the mean CFU (standard deviation) of L. casei Shirota was 13554.60 (4071.03) for the DD, 286.67 (73.99) for the US (97.89% reduction), and 4.5 (0.58) CFU for the UT-SC (p < 0.0001), establishing a further 98.43% reduction between UT and UT with SC. The UT with SC model proved effective in reducing dispersion from the UT, endorsing its use as an additional strategy to reduce PCDP in the dental environment in times of pandemic.

Mechanical Properties and Wear Resistance of Commercial Stainless Steel Used in Dental Instruments

The aim of this study was to investigate the element composition and grain size of commercial dental instruments used for ultrasonic scaler tips, which are composed of stainless-steel materials. The differences in mechanical properties and wear resistances were compared. The samples were classified into 4 groups in accordance with the manufacturer, Electro Medical Systems, 3A MEDES, DMETEC and OSUNG MND, and the element compositions of each stainless-steel ultrasonic scaler tip were analyzed with micro-X-ray fluorescence spectrometry (μXRF) and field-emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS). One-way ANOVA showed that there were significant differences in shear strength and Vickers hardness among the stainless-steel ultrasonic scaler tips depending on the manufacturer (p < 0.05). The mass before and after wear were found to have no significant difference among groups (p > 0.05), but there was a significant difference in the wear volume loss (p < 0.05). The results were then correlated with μXRF results as well as observations of grain size with optical microscopy, which concluded that the Fe content and the grain size of the stainless steel have significant impacts on strength. Additionally, stainless-steel ultrasonic scaler tips with higher Vickers hardness values showed greater wear resistance, which would be an important wear characteristic for clinicians to check.

Assessment of implant surface and instrument insert changes due to instrumentation with different tips for ultrasonic-driven debridement

Background

To assess the changes of implant surfaces of different roughness after instrumentation with ultrasonic-driven scaler tips of different materials.

Methods

Experiments were performed on two moderately rough surfaces (I—Inicell® and II—SLA®), one surface without pre-treatment (III) and one smooth machined surface (IV). Scaler tips made of steel (A), PEEK (B), titanium (C), carbon (D) and resin (E) were used for instrumentation with a standardized pressure of 100 g for ten seconds and under continuous automatic motion. Each combination of scaler tip and implant surface was performed three times on 8 titanium discs. After instrumentation roughness was assessed by profilometry, morphological changes were assessed by scanning electron microscopy, and element distribution on the utmost surface by energy dispersive X-ray spectroscopy.

Results

The surface roughness of discs I and II were significantly reduced by instrumentation with all tips except E. For disc III and IV roughness was enhanced by tip A and C and, only for IV, by tip D. Instrumentation with tips B, D and E left extensive residuals on surface I, II and III. The element analysis of these deposits proved consistent with the elemental composition of the respective tip materials.

Conclusion

All ultrasonic instruments led to microscopic alterations of all types of implants surfaces assessed in the present study. The least change of implant surfaces might result from resin or carbon tips on machined surfaces.

Clinical evaluation of ultrasonic subgingival debridement versus ultrasonic subgingival scaling combined with manual root planing in the treatment of periodontitis: study protocol for a randomized controlled trial

BACKGROUND

Periodontal diseases are regarded as the most common diseases of mankind. The prevalence rate of periodontal disease assumes a clear growth tendency, increasing by 57.3% from 1990 to 2010. Thereby, effective periodontal therapy is still a long-term task and a difficult problem. The goals of periodontal therapy are to eliminate the infectious and inflammatory processes of periodontal diseases. Root planing, in order to eliminate the "infected cementum," has been an important step in the treatment of periodontitis since the 1970s. However, along with the understanding of the effects of endotoxin on the root surface, the necessity of manual root planing has been gradually queried. Ultrasonic instruments, which are more recent innovations, would not remove the cementum excessively, and are also more time-saving and labor-saving compared to using hand instruments. Hence, an increasing number of dentists prefer to do scaling with ultrasonic instruments only. However, the necessity of root planing remains emphasized in the international mainstream views of periodontal mechanical treatment. Therefore, this study is devoted to compare the clinical effect of ultrasonic subgingival debridement and ultrasonic subgingival scaling combined with manual root planing, which takes the implementation of root planing as the only variable and is more in line with the current clinical situation, thus hoping to provide some valuable reference to dentists.

METHODS/DESIGN

Forty adult patients who fit the inclusion criteria are being recruited from the Peking University Hospital of Stomatology (Beijing, China). By means of randomization tables, one quadrant of the upper and lower teeth is the test group and the other is the control group. Test group: ultrasonic subgingival scaling combined with manual root planing.

CONTROL GROUP

ultrasonic subgingival debridement. In a 24-week follow-up period, plaque index, probing depth, clinical attachment loss, bleeding index, furcation involvement, mobility, and patient-reported outcome (Visual Analog Scale for pain and sensitivity) will be observed and documented.

DISCUSSION

This study evaluates the effectiveness of ultrasonic subgingival scaling combined with manual root planing and ultrasonic subgingival debridement alone in the nonsurgical treatment of periodontitis with a split-mouth design after 1, 3 and 6 months. The result of the trial should potentially contribute to an advanced treatment strategy for periodontitis with an ideal clinical outcome.

TRIAL REGISTRATION

International Clinical Trials Registry Platform (ICTRP), ID: ChiCTR1800017122. Registered on 12 July 2018.

The effect of miniaturized manual versus mechanical instruments on calculus removal and root surface characteristics: An in vitro light microscopic study

Objectives

The aim of this study was to evaluate by light microscopy analysis the effect of the use of miniaturised piezoelectric tips versus mini‐five area specific curets on calculus removal and postoperative root surface alterations.

Methods

A total of 20 extracted teeth were used. Two square surfaces (5×5 mm) were marked on each root surface with a diamond bur mounted on a high‐speed handpiece. Before and after instrumentation, a series of magnified images (4.2×) of each experimental surface were taken with a standardized approach. According to a randomization list, the two surfaces on each sample were instrumented in a standardised fashion either with a mine‐five curet or a slim piezoelectric tip. The images were processed using an imaging software. Data were summarised as means and standard deviations for the two outcomes (calculus and alterations.) at each time (pre and post) for both of the groups (manual and mechanical).

Results

Both manual and mechanical instrumentation significantly reduced the calculus deposits (p < .001) without significant differences between the two groups. Both manual and mechanical treatments significantly increased alterations (p < .01). There was a statistically significant evidence of a greater increase in alterations from mechanical treatment.

Conclusions

Slim mechanical piezoelectric tips and manual mini‐five area‐specific curets have similar effects on calculus removal. Manual instrumentation results in a more homogeneous postoperative root surface with less root alterations.

Clinical and microbiological effects of multiple applications of antibacterial photodynamic therapy in periodontal maintenance patients. A randomized controlled clinical study

BACKGROUND

At present, very limited data are available on the clinical and microbiological outcomes obtained following repeated application of aPDT following one single mechanical debridement.

OBJECTIVE

To evaluate clinically and microbiologically the outcomes following one single session of subgingival mechanical debridement (scaling and root planing; e.g. SRP) followed by 1x immediate application of aPDT and 2 x subsequent use of aPDT without SRP.

MATERIALS AND METHODS

Forty patients diagnosed with generalized chronic periodontitis that were enrolled in periodontal maintenance (supportive periodontal therapy) program, were randomly assigned to one of the two treatments: 1. SRP by means of ultrasonic and hand instruments followed by one single session of SRP followed by 1x immediate application of aPDT and 2 x subsequent applications of aPDT without SRP (test) or 2. SRP alone (control). The following clinical parameters were recorded at baseline, at 3 and 6 months: Full-Mouth Plaque Scores (FMPS), Full-Mouth Bleeding Scores (BOP), Probing Pocket Depth (PPD), Clinical Attachment Level (CAL) and Gingival Recession (RC). Additionally, microbiological samples were evaluated at baseline and six months after treatment. The primary outcome variable was BOP.

RESULTS

Both treatments improved statistically significantly (p < 0.05) the FMPS, PPD and CAL values, while no statistically significant changes occurred in terms of RC. In the test group, BOP decreased statistically significantly (p < 0.05) after 3 and 6 months, while in the control group the respective values decreased statistically significantly only at 3 months. Both treatments reduced statistically significantly the total bacteria counts (TBC) after 6 months (p < 0.05). At 6 months, the use of SRP and aPDT resulted in a statistically significant decrease in the number of all tested bacteria except A. actinomycetemcomitans while the use of SRP alone resulted only in a statistically significant decrease in the numbers of P. gingivalis, T. denticola and T. forsythia.

CONCLUSIONS

In periodontal patients enrolled in a maintenance program one single session of SRP followed by 3x application of aPDT, enhanced the clinical and microbiological outcomes compared to SRP alone.

In-vivo compatibility between pacemakers and dental equipment

In-vitro studies suggest that electromagnetic interference can occur under specific conditions involving proximity between electronic dental equipment and pacemakers. At present, in-vivo investigations to verify the effect of using electronic dental equipment in clinical conditions on patients with pacemakers are scarce. This study aimed to evaluate, in vivo, the effect of three commonly used electronic dental instruments - ultrasonic dental scaler, electric pulp tester, and electronic apex locator - on patients with different pacemaker brands and configurations. Sixty-six consecutive non-pacemaker-dependent patients were enrolled during regular electrophysiology follow-up visits. Electronic dental tools were operated while the pacemaker was interrogated, and the intracardiac electrogram and electrocardiogram were recorded. No interferences were detected in the intracardiac electrogram of any patient during the tests with dental equipment. No abnormalities in pacemaker pacing and sensing function were observed, and no differences were found with respect to the variables, pacemaker brands, pacemaker configuration, or mode of application of the dental equipment. Electromagnetic interferences affecting the surface electrocardiogram, but not the intracardiac electrogram, were found in 25 (37.9%) patients, especially while using the ultrasonic dental scaler; the intrinsic function of the pacemakers was not affected. Under real clinical conditions, none of the electronic dental instruments tested interfered with pacemaker function.

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.

Clinical effects of photodynamic therapy as an adjunct to full-mouth ultrasonic scaling and root planing in treatment of chronic periodontitis

Background and aims

Photodynamic therapy (PDT) is a potential strategy to eliminate infection in the specific tissue. It uses lower-power laser to activate a photosensitizing agent. Studies have shown the benefit of PDT in the periodontal treatment. The aim of this study was to evaluate the periodontal changes after applying PDT as an adjunct to one visit full-mouth SRP (scaling and root planing) with subgingival piezoelectric ultrasonic scaler compared with full-mouth SRP alone.

Methods

A split-mouth randomized clinical trial was designed. Twenty patients with moderate to severe chronic periodontitis were treated with subgingival piezoelectric ultrasonic device alone in control group and adjunct treated with PDT in the test group. Probing pocket depth (PD), clinical attachment level (CAL), plaque index (PI), gingival bleeding index (GBI) and gingival inflammation index (GI) were evaluated at baseline, 1 month, 3 and 6 months after treatment. Only sites with PD ≥ 4 mm at baseline were calculated.

Results

All periodontal parameters were significantly improved in both groups at 1 month, 3 and 6 months after treatment. All parameters in test group were better than that control group, with statistically significant differences of GBI and GI (P < 0.05) at 3 and 6 months after treatment but no statistically significant differences of PD, CAL and PI.

Conclusions

One visit full-mouth ultrasonic SRP seems to have good enough effort for the periodontal status till 6 months. The adjunct treatment of PDT provided positive effect in term of GBI and GI.

Influence of Hand Instrumentation and Ultrasonic Scaling on the Microleakage of various Cervical Restorations: An in vitro Study

INTRODUCTION

In cervical lesions, various restorative materials can be inserted, which can be affected by the application of periodontal scalers. This study evaluated and compared the marginal seal of class V glass ionomer, composite resin, and amalgam restorations after subjecting them to hand instrumentation and ultrasonic scaling.

MATERIALS AND METHODS

In this experimental study, 30 sound human first premolars were selected. In each tooth, buccal and lingual cavities (4 mm mesiodistal width, 3 mm occlusogingival height, and 2 mm depth) were made. The teeth were randomly assigned to three groups of 10 teeth: (1) Glass ionomer group, (2) composite group, and (3) amalgam group. Teeth were subjected to thermocycling procedure for 1,000 cycles between 5 and 55°C water baths and a 1-minute dwell time. Then, each group was randomly subdivided: (1) Margins of 30 restorations were exposed to hand instrumentation procedures by applying 10 working strokes, (2) margins of 30 restorations were exposed to a periodontal tip mounted on a piezoelectric ultrasonic handpiece working at 25 kHz for 10 seconds. The specimens were serially sectioned mesiodistally. Each section was examined under a stereomicroscope. The extent of microleakage was ranked using a 0 to 4 scale at both occlusal and cervical margins of the restorations. Data were analyzed initially using the Kruskal-Wallis test, followed by multiple comparisons using the Mann-Whitney and Wilcoxon test.

RESULTS

The type of restorative material had a significant influence on dye penetration, whether in the enamel margin or in the dentinal margin (p < 0.001). The microleakage of glass ionomer group was the highest. No statistical differences were found in dye penetration between scaling groups (hand instrumentation and ultrasonic scaling) (p > 0.05).

CONCLUSION

Type of restorative material had a significant influence on microleakage. No statistical differences were found in dye penetration between scaling groups.

CLINICAL SIGNIFICANCE

The microleakage of glass ionomer restoration is greater than amalgam and composite restorations after subjecting them to hand instrumentation and ultrasonic scaling.

Microleakage around Class V Composite Restorations after Ultrasonic Scaling and Sonic Toothbrushing around their Margin

Objectives

To measure microleakage around class V composite restorations after piezoelectric ultrasonic scaling and sonic toothbrushing.

Methods

3 mm × 2 mm × 1.5 mm boxes were prepared on buccal and lingual surfaces of extracted molars centered on the cementum‐enamel junction. Half the preparations were beveled (0.5 mm). Preparations were restored with composite and polished. Restorations on one side of the teeth were either traced with an ultrasonic scaler (60 seconds, n = 16) or brushed in a sonic toothbrushing machine (2 hours, n = 16). After thermocycling (10,000 cycles/5–55°C), specimens were immersed in 5 wt% Fuchsine solution (24 hours). Samples were sectioned and evaluated for percentage of dye penetration. Data were analyzed with an exact Wilcoxon rank‐sum test and exact Wilcoxon signed‐rank test (alpha = 0.05).

Results

Microleakage was observed at the cementum‐composite interface but not the enamel‐composite interface. There was not a statistically significant effect of the bevel for ultrasonic scaling or for sonic toothbrushing. Data obtained with and without a bevel were combined and a statistically significant difference in microleakage between the treatment and control sides of the tooth were found for ultrasonic scaling (32.5%±44.9%, n = 16; p = 0.016) but not sonic toothbrushing (2.5% ± 41.2%, n = 16; p = 1.0).

Conclusions

Piezoelectric ultrasonic scaling increased microleakage at cementum‐composite interface and there was no difference in microleakage with the use of a bevel.

Clinical Significance

Piezoelectric sonic scaling around Class V composite restorations with margins in cementum should be avoided. Beveled margins will not reduce the incidence of microleakge resulting from ultrasonic scaling in Class V restorations. Placing the apical margin of the restoration in enamel should be attempted whenever possible to prevent future microleakage. (J Esthet Restor Dent 29:41–48, 2017)

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.

Efficacy versus health risks: An in vitro evaluation of power-driven scalers

Background:

Power-driven instrumentation of root surfaces during supportive periodontal therapy is an alternative to hand instrumentation. The purpose of this pilot in vitro study was to investigate the efficacy of sub- and supragingival plaque removal with a sonic (AIR: Synea, W and H, Bürmoos, Austria) and two ultrasonic devices (TIG: Tigon+, W and H, Bürmoos, Austria; VEC: Vector, Dürr, Bietigheim-Bissingen, Germany) as well as the health-risk for dental professionals during treatment.

Materials and Methods:

The power-driven devices were utilized to remove plaque from model teeth in dummy heads. The percentage of residual artificial plaque after 2 min of supra- or subgingival instrumentation was calculated by means of image-processing techniques at four sites (n = 576) of each tooth. The Health-Risk-Index (HRI: spatter/residual plaque quotient) with the different power-driven devices was assessed during treatment.

Results:

The smallest amounts of residual plaque were found for the sonic device AIR (8.89% ± 10.92%) and the ultrasonic scaler TIG (8.72% ± 12.02%) (P = 0.707). Significantly more plaque was remained after the use of the ultrasonic scaler VEC (18.76% ± 18.07%) (P < 0.001). Irrespectively of the scaler, efficacy was similar sub- (10.7% ± 11.6%) and supragingivally (13.5% ± 17.2%) (P = 0.901). AIR/TIG demonstrated equal residual amounts of plaque sub- (P = 0.831) as well as supragingivally (P = 0.510). However, AIR/VEC and TIG/VEC were significantly in favor of AIR and TIG (P < 0.001). In contrast, the lowest HRI was found after using VEC (0.0043) and differed considerably for AIR (0.2812) and TIG (0.0287).

Conclusion:

Sonic devices are as effective as ultrasonic devices in the removal of biofilm but bear a higher risk to the dental professional's health concerning the formation of spatter.

The effect of the angle of instrumentation of the Piezoelectric Ultrasonic Scaler on root surfaces

OBJECTIVES

To evaluate the influence of variations in the working angle of the piezoelectric ultrasonic scaler (PUS) on root surfaces.

MATERIAL AND METHODS

Fifty-five uniradicular bovine teeth were used, of which 25 teeth were used for the analysis of the roughness and root wear, while the remaining 30 teeth were used for the analysis of morphology (MRS) and the attachment of blood components (ABC). The teeth were randomly divided into five groups according to the type of treatment (G1-G5: piezoelectric ultrasonic scaler; G6: manual curette) and to the PUS working angle applied (G1: 0°; G2: 30°; G3: 45°; G4: 60°; G5: 90°). For statistical analysis, the data describing the MRS and ABC were analysed by the Kruskal-Wallis and Dunn's tests, and the data describing the roughness and tooth wear were analysed by anova and Tukey's tests at the significance level of 5%.

RESULTS

Manual curette (MC) promoted a smoother root surface than the application of the PUS. The PUS used at the angles of 30° and 45° resulted in a high level of ABC that was comparable to that obtained by MC. Additionally, the group in which the PUS was applied at an angle of 45° exhibited less tooth wear than the other groups.

CONCLUSIONS

Changes in the working angle of the PUS influenced the characteristics of root surfaces after instrumentation.

Interference between dental electrical devices and pacemakers or defibrillators: results from a prospective clinical study

BACKGROUND

The authors aimed to determine whether electrical dental devices would interfere with the function of cardiac pacemakers or implantable cardioverter defibrillators (ICDs) in humans.

METHODS

The authors exposed asymptomatic nonpacemaker-dependent patients to commonly used electrical dental equipment (for example, battery-operated curing lights, ultrasonic baths, ultrasonic scalers, electric pulp testers, and electric toothbrushes) in an outpatient cardiology clinic. The authors operated dental devices at various distances and programmed cardiac devices to sense and pace. The authors obtained cardiac tracings using a cardiac programming unit and a cardiac provider who noted any interference interpreted the results in real time.

RESULTS

The authors enrolled 32 consecutive patients and tested 12 pacemakers and 20 ICDs. They did not observe any significant clinical interference in sensing and pacing functions in any patient; however, they noted minor interference without clinical impact in the telemetry from the cardiac programming unit during use of the ultrasonic scaler and bath.

CONCLUSIONS

The findings of this prospective study suggest that electrical devices commonly used in dental practices do not interfere with the sensing and pacing of contemporary cardiac patients' pacemakers or ICDs. However, they do interfere with the telemetry from the cardiac programming unit, without any clinical impact on patient safety. These findings should help in the development of clinical guidelines regarding dental management of patients with pacemakers or ICDs.

PRACTICAL IMPLICATIONS

Electrical dental devices (for example, ultrasonic baths, ultrasonic scalers) induced minor interference with programmers that interrogate cardiac devices implanted in patients; however, overall, dental devices do not appear to interfere with pacemakers' and defibrillators' pacing and sensing function.

Trauma from instrumentation after non-surgical periodontal treatment with ultrasonic scalers and Nd:YAG laser

OBJECTIVE

Periodontal therapies aimed at altering the progression of periodontal diseases must include meticulous mechanical debridement during both the non-surgical and the surgical phases of periodontal treatment. The aim of this study was to evaluate and compare the immediate effect of trauma from instrumentation on clinical attachment level after non-surgical periodontal treatment with ultrasonic scalers and a Nd:YAG laser.

MATERIALS AND METHODS

Twenty-four patients with untreated chronic periodontitis, presenting probing depths of 4-6 mm on anterior teeth, upper and lower, were entered into the study. The selected teeth were probed with a pressure-controlled probe, guided by stents. Each quadrant was randomly allocated in a split-mouth design either to treatment with Nd:YAG laser using an energy of 1W, 100mj, 1064nm (test group) or to periodontal treatment using ultrasonic scalers (control group). Clinical parameters, including plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and probing attachment level (PAL) were acquired prior to and immediately after treatment.

RESULTS

Statistical analysis demonstrated no differences between groups at baseline for all parameters (p > 0.05). Immediately after treatment, the control group showed a greater PAL loss than the test group (p < 0.05). For the control group, there were statistically significant differences between PAL immediately before and after treatment (p < 0.05), but not test group (p > 0.05).

CONCLUSIONS

Within the limits of the present study, it may be concluded that non-surgical periodontal treatment with ultrasonic scalers causes a mean immediate attachment loss of 0.68 mm and that a Nd:YAG laser seems to reduce significantly the trauma the instrumentation produced.

Flap approaches in plastic periodontal and implant surgery: critical elements in design and execution

AIM

To identify critical elements in design and execution of coronally advanced flap, lateral positioned flap and their variations for the treatment of facial gingival recessions or peri-implant soft tissue dehiscences.

MATERIALS AND METHODS

Clinical studies were identified with both electronic and hand searches, and examined for the following aspects: flap design and incision techniques, flap elevation, root conditioning, flap mobility, flap stability and suturing. Moreover, prognostic factors for complete recession coverage were identified.

RESULTS

Some critical elements are evident in flap design and execution: the dimension and the thickness of tissue positioned over the denuded roots; the use on root surface of enamel matrix derivate; the stability and suturing of the flap in a position coronal to the cemento-enamel junction. The pre-determination of the clinical cemento-enamel junction, smoking status, operator surgical skills and the compliance to a supportive care programme have a role in obtaining and maintaining a complete root coverage.

CONCLUSIONS

Different flap approaches are available when performing periodontal plastic surgery, resulting in a great variability in clinical outcomes. The possibility of using pedicle flaps alone to achieve complete soft tissue coverage of facial implant dehiscence has not yet been investigated.

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.

Rotary instruments in the treatment of chronic periodontitis: A randomized clinical trial

Background:

The study aimed at comparing the effectiveness of rotary instruments with hand instruments in non-surgical treatment of chronic periodontitis.

Materials and Methods:

Thirty-eight patients with chronic periodontitis, enrolled to this randomized, controlled clinical trial, were divided into two groups. Patients in the control group received scaling and root planing with hand instruments, whereas patients in the test group received treatment with rotary instruments. Clinical assessment by plaque index, bleeding on probing, probing depth, gingival recession, and clinical attachment level was made prior to and at 6 months after treatment. Differences in the clinical parameters were analyzed using the Wilcoxon signed rank test and Mann–Whitney U test.

Results:

Both treatments resulted in a significant improvement in all clinical recordings, but no differences in any of the investigated parameters were observed at baseline between the two groups.

Conclusion:

Non-surgical periodontal therapy with the tested rotary instruments may lead to clinical improvements comparable to those obtained with conventional hand instruments.

Mechanized scaling with ultrasonics: Perils and proactive measures

Mechanized scaling for plaque removal is a routine procedure in the practice of periodontics. Though it appears innocuous by itself, there are retinues of hazards associated with it on various organ systems in the body. Some of these unwanted effects and measures to avoid or ameliorate the same are elaborated here. Exposure to ultrasonic scaling is inevitable before any other treatment procedure. Aerosol contamination, vibrational hazards, thermal effects on the dental pulp, altered vascular dynamics, disruption in electromagnetic device, diminished hearing and dental unit waterline contamination are some of the probable off-shoots a patient has to bear. Uses of barrier devices, proper attention to usage of equipment, protection for ear and water treatment are few of solutions for the same. Though documented evidence for the existence of all effects is lacking, it is never the less significant for the overall safety of the patient. A conscientious clinician should therefore inculcate the available steps to overcome the hazards of ultrasonic scaling.

Tumor necrosis factor- α and interleukin-6: potential interorgan inflammatory mediators contributing to destructive periodontal disease in obesity or metabolic syndrome

Obesity has become a worldwide health burden in the last two decades. Obesity has been associated with increased comorbidities, such as coronary artery disease, diabetes, and destructive periodontal disease. Obesity is also part of a group of risk factors occurring together in an individual, which is referred to as metabolic syndrome. Clinical studies have shown higher risk for destructive periodontal disease in obesity and metabolic syndrome. However, the role of obesity and metabolic syndrome in the onset and development of destructive periodontal disease has not yet been fully understood. In this review, we discuss a working model, which focuses on interorgan inflammation as a common etiological factor for destructive periodontal disease associated with obesity and metabolic syndrome. Specifically, we suggest that elevated levels of tumor necrosis factor- α (TNF- α ) or interleukin 6 (IL-6)--both adipokines and known risk factors for destructive periodontal disease--in obesity and metabolic syndrome contribute to the onset and development of destructive periodontal disease. The connections between destructive periodontal disease and systemic conditions, such as obesity or metabolic syndrome, are complex and potentially multidirectional. This review largely focuses on TNF- α and IL-6, inflammatory mediators, as potential common risk factors and does not exclude other biological mechanisms.

Do ultrasonic dental scalers interfere with implantable cardioverter defibrillators? An in vivo investigation

OBJECTIVES

To test the in vivo effects of an ultrasonic dental scaler on various implanted cardioverter defibrillator (ICD) models.

METHODS

12 consecutive patients with ICDs had continuous both electrocardiogram monitoring and device interrogation to detect interferences during the use of an ultrasonic dental scaler.

RESULTS

No interferences were detected by any ICD. Evaluation of the electrocardiograms for each patient failed to show any abnormalities in pacing during testing.

CONCLUSION

The results of this study suggest that the routinary clinic use of piezoelectric dental scalers do not interfere with the functioning of any of the tested ICDs.

CLINICAL SIGNIFICANCE

Ultrasonic dental scalers have been suspected of electromagnetic interference (EMI) with the normal functioning of ICDs and the use of this type of equipment for patients with these devices has been controversial. This is the first in vivo study to investigate EMI of ICD activity during the operation with ultrasonic dental scaler.

Low-cost periodontal therapy

Periodontitis is a complex infectious disease that affects low-income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low-cost periodontal therapy that involves professional and patient-administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone-iodine and sodium hypochlorite have all the characteristics for becoming the first-choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin-metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle-aged patients, and ciprofloxacin-metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent use of inexpensive antimicrobial agents can significantly retard or arrest progressive periodontitis in the great majority of patients.

Debridamento ultrassônico de boca toda no tratamento da periodontite crônica: uma revisão sistematizada

INTRODUÇÃO: O debridamento ultrassônico de boca toda visa a uma instrumentação mais leve e conservadora da superfície radicular, evitando a recolonização da bolsa periodontal. OBJETIVO: Este trabalho verificou os efeitos do debridamento subgengival com o uso de ultrassom sobre os parâmetros clínicos periodontais no tratamento da periodontite crônica por meio de uma revisão na literatura. MATERIAL E MÉTODO: A revisão foi realizada nas bases de busca bibliográfica PubMed, Lilacs, Scielo, Medline e Centro de Registro de Ensaios Clínicos Controlados (Biblioteca Cochrane). Foram incluídas publicações na língua inglesa que abordaram estudos clínicos de intervenção em humanos, randomizados e controlados, e que utilizaram o debridamento ultrassônico para o tratamento não cirúrgico da periodontite crônica. RESULTADO: Inicialmente, foram encontradas 167 referências e, a partir da análise dos títulos e resumos, dez estudos perfizeram as características exigidas e foram considerados válidos para a realização desta revisão. Os estudos mostraram que a abordagem pelo debridamento ultrassônico pode ser terapia favorável ao tratamento da periodontite crônica. CONCLUSÃO: O tratamento da periodontite crônica por meio do debridamento ultrassônico periodontal de boca toda produz resultados clínicos semelhantes aos conseguidos na raspagem e no alisamento radicular convencionais.

Clearance of topically-applied PVP-iodine as a solution or gel in periodontal pockets in men

OBJECTIVES

The aim of the study was to investigate the clearance of PVP-iodine applied as a gel or solution in periodontal pockets.

METHODS

Teeth of 12 subjects with at least eight periodontal pockets of ≥5 mm probing depth were isolated with a rubber dam to allow contamination-free access to the pockets. In each subject, three pockets were filled with PVP-iodine gel (10%) and three with PVP-iodine solution (10%). One pocket of each subject without iodine application served as a negative control. The treatment allocation was assigned randomly. Any excess material was removed subsequently. After 1, 5 and 15 min, a paper point was used to collect the sulcus liquid and the concentration of PVP-iodine was chemically determined. In addition, PVP-iodine gel was administered into 12 periodontal pockets immediately after sub-gingival ultrasound debridement and the concentration of PVP-iodine was determined after 1 min.

RESULTS

Descending concentrations of PVP-iodine were determined at 1, 5 and 15 min after the application. No PVP-iodine was found in the pockets serving as negative controls. The mean concentrations of the gel and solution were 6.14 μg/ml and 4.44 μg/ml (1 min; p ≥ 0.028), 3.20 μg/ml and 1.44 μg/ml (5 min; p ≥ 0.126), 0.69 μg/ml and 0.23 μg/ml (15 min; p ≤ 0.019), respectively. In the pockets with previous debridement the mean concentration was 1.68 ± 1.97 μg/ml.

CONCLUSION

The application of PVP-iodine gel in periodontal pockets allows a prolonged remnant effect as compared to that of the solution formula.

A comparative evaluation of the efficacy of manual, magnetostrictive and piezoelectric ultrasonic instruments--an in vitro profilometric and SEM study

Objectives

The debridement of diseased root surface is usually performed by mechanical scaling and root planing using manual and power driven instruments. Many new designs in ultrasonic powered scaling tips have been developed. However, their effectiveness as compared to manual curettes has always been debatable. Thus, the objective of this in vitro study was to comparatively evaluate the efficacy of manual, magnetostrictive and piezoelectric ultrasonic instrumentation on periodontally involved extracted teeth using profilometer and scanning electron microscope (SEM).

Material and Methods

30 periodontally involved extracted human teeth were divided into 3 groups. The teeth were instrumented with hand and ultrasonic instruments resembling clinical application. In Group A all teeth were scaled with a new universal hand curette (Hu Friedy Gracey After Five Vision curette; Hu Friedy, Chicago, USA). In Group B Cavitron^TM FSI - SLI^TM ultrasonic device with focused spray slimline inserts (Dentsply International Inc., York, PA, USA) were used. In Group C teeth were scaled with an EMS piezoelectric ultrasonic device with prototype modified PS inserts. The surfaces were analyzed by a Precision profilometer to measure the surface roughness (Ra value in µm) consecutively before and after the instrumentation. The samples were examined under SEM at magnifications ranging from 17x to 300x and 600x.

Results

The mean Ra values (µm) before and after instrumentation in all the three groups A, B and C were tabulated. After statistically analyzing the data, no significant difference was observed in the three experimental groups. Though there was a decrease in the percentage reduction of Ra values consecutively from group A to C.

Conclusion

Within the limits of the present study, given that the manual, magnetostrictive and piezoelectric ultrasonic instruments produce the same surface roughness, it can be concluded that their efficacy for creating a biologically compatible surface of periodontally diseased teeth is similar.

Er:YAG laser treatment in supportive periodontal therapy

OBJECTIVE

To assess clinical and microbiological outcomes of an Er:YAG laser in comparison with sonic debridement in the treatment of persistent periodontal pockets in a prospective randomized controlled multicentre study design.

MATERIAL AND METHODS

A total of 78 patients in supportive periodontal therapy with two residual pockets were included, 58 were available for the whole follow-up period. Root surfaces were instrumented either with a sonic scaler (Sonicflex(®) 2003 L) or with an Er:YAG laser (KEY Laser(®) 3). Clinical attachment levels (CAL), Probing depths (PD), Plaque control record (PCR) and Bleeding on probing (BOP) were assessed at baseline, 13 and 26 weeks after treatment. In addition, microbiological analysis was performed employing a DNA diagnostic test kit (micro-IDent(®) Plus).

RESULTS

Probing depths and CAL were significantly reduced in both groups over time (p < 0.05), without significant differences between the groups (p > 0.05). BOP frequency values decreased significantly within both groups (p < 0.05), with no difference between the laser and the sonic treatment (p > 0.05). PCR frequency values did not change during the observation period (p > 0.05). Microbiological analysis failed to expose any significant difference based on treatment group or period.

CONCLUSION

Employing both sonic and laser treatment procedures during supportive periodontal care, similar clinical and microbiological outcomes can be expected.

Effect of 1,064-nm Nd:YAG laser therapy on GCF IL-1β and MMP-8 levels in patients with chronic periodontitis

The aim of this study was to evaluate the long-term effects of a combined periodontal treatment of scaling and root planing (SRP) and Nd:YAG laser (NDL) in chronic periodontitis (CP) patients. This was accomplished by determining the periodontal indices and the interleukin-1beta (IL-1β) and matrix metalloproteinase-8 (MMP-8) levels of the gingival crevicular fluid (GCF). This study was performed according to a random split-mouth-design, controlled clinical trial for sulcular debridement on 40 teeth from 20 patients with generalized moderate chronic periodontitis. The periodontal healing outcomes were compared after periodontal treatment with either SRP + NDL at 1 W (test side) or SRP (control side). Plaque index (PI), gingival index (GI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, and samples of gingival crevicular fluid (GCF) were taken at baseline and post-therapy (3 and 9 months after treatment). The GCF samples were analyzed for IL-1β and MMP-8. There was postoperative improvement of all clinical parameters in both groups, but test side GI, PPD, and CAL recovery was higher than that of the control side (p < 0.05). Although levels of IL-1β and MMP-8 in GCF after treatment were lower in the test side than the control side, there was not a statistically significant difference (p > 0.05). In the long term, we found that SRP + NDL treatment of periodontal pockets was more effective than SRP alone in reducing PPD, CAL, GI, and GCF values.

A scanning electron microscopy study of diseased root surfaces conditioned with EDTA gel plus Cetavlon after scaling and root planing

In the present investigation, a scanning electron microscopy analysis was performed to evaluate the effects of the topical application of ethylenediaminetetraacetic acid (EDTA) gel associated with Cetavlon (EDTAC) in removing the smear layer and exposing collagen fibers following root surface instrumentation. Twenty-eight teeth from adult humans, single rooted and scheduled for extraction due to periodontal reasons, were selected. Each tooth was submitted to manual (scaling and root planing) instrumentation alone or combined with ultrasonic instruments, with or without etching using a 24% EDTAC gel. Following extraction, specimens were processed and examined under a scanning electron microscope. A comparative morphological semi-quantitative analysis was performed; the intensity of the smear layer and the decalcification of cementum and dentinal surfaces were graded in 12 sets using an arbitrary scale ranging from 1 (area covered by a smear layer) to 4 (no smear layer). Root debridement with hand instruments alone or combined with ultrasonic instruments resulted in a similar smear layer covering the root surfaces. The smear layer was successfully removed from the surfaces treated with EDTAC, which exhibited numerous exposed dentinal tubules and collagen fibers. This study supports the hypothesis that manual instrumentation alone or instrumentation combined with ultrasonic instrumentation is unable to remove the smear layer, whereas the subsequent topical application of EDTAC gel effectively removes the smear layer, uncovers dentinal openings and exposes collagen fibers.

In vitro adhesion of Streptococcus sanguinis to dentine root surface after treatment with Er:YAG laser, ultrasonic system, or manual curette

OBJECTIVE

The purpose of this in vitro study was to evaluate the dentine root surface roughness and the adherence of Streptococcus sanguinis (ATCC 10556) after treatment with an ultrasonic system, Er:YAG laser, or manual curette.

BACKGROUND DATA

Bacterial adhesion and formation of dental biofilm after scaling and root planing may be a challenge to the long-term stability of periodontal therapy.

MATERIALS AND METHODS

Forty flattened bovine roots were randomly assigned to one of the following groups: ultrasonic system (n = 10); Er:YAG laser (n = 10); manual curette (n = 10); or control untreated roots (n = 10). The mean surface roughness (Ra, microm) of the specimens before and after exposure to each treatment was determined using a surface profilometer. In addition, S. sanguinis was grown on the treated and untreated specimens and the amounts of retained bacteria on the surfaces were measured by culture method.

RESULTS

All treatments increased the Ra; however, the roughest surface was produced by the curettes. In addition, the specimens treated with curettes showed the highest S. sanguinis adhesion. There was a significant positive correlation between roughness values and bacterial cells counts.

CONCLUSION

S. sanguinis adhesion was the highest on the curette-treated dentine root surfaces, which also presented the greatest surface roughness.

Inhibitory effects of low-energy pulsed ultrasonic stimulation on cell surface protein antigen C through heat shock proteins GroEL and DnaK in Streptococcus mutans

This study concerns the use of low-energy pulsed ultrasound as nondestructive photodynamic antimicrobial therapy for controlling dental plaque. We examined the antibacterial and bactericidal effects of low-energy pulsed ultrasound on mutans streptococci and its inhibitory effects on bacterial cell adhesion of Streptococcus mutans. The results indicated weak antibacterial and bactericidal effects. However, ultrasonic stimulation for less than 20 min markedly decreased bacterial cell adhesion. To analyze the mechanism underlying the inhibitory effect, we examined cell surface protein antigen C (PAc) and glucosyltransferase I (GTF-I) expression in S. mutans. The levels of PAc gene and protein expression were markedly decreased by ultrasonic stimulation for 20 min. However, no change in GTF-I expression was observed. The expression of stress response heat shock proteins GroEL and DnaK was also examined. GroEL and DnaK levels were significantly decreased by ultrasonic stimulation, and the expression of the PAc protein was also diminished upon the addition of GroEL or DnaK inhibitors without ultrasonic stimulation. These observations suggest that the expression of the PAc protein in S. mutans may be dependent on heat shock proteins. Thus, low-energy pulsed ultrasound decreases bacterial adhesion by the inhibitory effect on the PAc protein and heat shock protein expression and may be useful as photodynamic antimicrobial chemotherapy in controlling dental plaque.

Comparative in vitro study of root roughness after instrumentation with ultrasonic and diamond tip sonic scaler

Objective:

The purpose of this study was to evaluate the root surface roughness after instrumentation with hand curette and diamond-coated sonic and universal ultrasonic tips.

Materials and Methods:

Forty root surfaces of human teeth were randomly assigned to four treatment groups: control group (without instrumentation), curette instrumentation, ultrasonic instrumentation with universal tip and sonic instrumentation with diamond-coated tip. Each sample was instrumented with fifteen strokes. Before and after instrumentation, surface roughness was measured. In addition, the root surface topography was examined after treatment under the scanning electron microscope.

Results:

Significant statistical differences (p<0.05) were observed when comparing the control group (0.48±0.07mm) to the treated groups (hand - 1.246±0.279mm, ultrasonic - 1.468±0.177mm and sonic instrumentation - 1.576±0.20mm). The highest roughness was produced by diamond-coated sonic tip and by ultrasonic universal tip (p>0.05).

Conclusion:

The diamond-coated tip with sonic scaler instrumentation and ultrasonic instrumentation produce similar root surface roughness, higher than curette instrumentation.

Systematic review on the effect of rinsing with povidone-iodine during nonsurgical periodontal therapy

BACKGROUND AND OBJECTIVE

The existing literature is inconsistent regarding whether there is any additional effect of povidone-iodine (PVP-iodine) as an adjunctive to scaling and root planing, and, if there is an effect, what its size is. Therefore, the aim of this study was to assess the additional effect of PVP-iodine as an adjunct to scaling and root planing compared with water, saline or no rinse in the treatment of chronic periodontitis.

MATERIAL AND METHODS

An electronic literature search of the databases PubMed, EMBASE and the Cochrane Central Library, and a handsearch, were performed (up to November 2008). Two reviewers independently identified and selected screened abstracts for possible inclusion, and assessed randomized, controlled clinical trials comparing the additional benefit of PVP-iodine with water, saline rinsing or no rinsing in the nonsurgical periodontal therapy of patients with chronic periodontitis. A fixed-effects meta-analysis was conducted in the absence of statistically significant heterogeneity.

RESULTS

A small, but statistically significant additional beneficial effect of the adjunctive use of PVP-iodine with enhanced probing pocket depth reductions of 0.28 mm (95% confidence interval: 0.08 to 0.48, p = 0.007) was found. There was no significant heterogeneity between studies (I(2) = 0%). However, most of the studies included in the meta-analysis were of low quality, and the treatment modalities showed various differences such as the use of PVP-iodine at different concentrations and application modalities. Nevertheless, single-rooted teeth, in particular, showed an additional benefit after scaling and root planing with PVP-iodine, particularly when the treatment was repeated during the healing stage.

CONCLUSION

The adjunctive use of PVP-iodine during scaling and root planing may increase the clinical pocket depth reduction, although the clinical significance is small to moderate.

The effect of the Vector scaler system on human teeth: a systematic review

AIM

To review the available literature, considering the effect of instrumentation with the Vector ultrasonic scaler on human teeth in vitro and in vivo compared to conventional ultrasonic instruments and/or hand instrumentation. The assessed effects are calculus removal, time of instrumentation, root surface aspects, cell attachment, patients' perception, bleeding upon probing, pocket depth, clinical attachment loss and microbiological effects.

MATERIALS AND METHODS

MEDLINE-PubMed and the Cochrane Central register of controlled trials (CENTRAL) were searched up through January 2008 to identify appropriate studies.

RESULTS

Independent screening of the titles and abstracts of 270 MEDLINE-PubMed and 15 Cochrane papers resulted in 15 suitable publications. The studies differed in design and outcome, so this review summarizes the outcomes in a descriptive manner. Comparisons are presented against conventional ultrasonic system and scaling and root planing.

CONCLUSION

The Vector ultrasonic scaler provided comparable clinical and microbiological periodontal healing results as scaling and root planing and conventional ultrasonic system in moderately deep pockets. The Vector ultrasonic scaler may be used as a gentle root debridement device for supportive periodontal therapy, as an alternative to other conventional ultrasonic system. The operator should however consider the extra time needed for instrumentation.