The effect of subgingival debridement with hand and ultrasonic instruments on the subgingival microflora

Periodontal instrumentation technique: an exploratory analysis of clinical outcomes and financial aspects

Objective This exploratory post hoc analysis sought to investigate clinical outcomes comparing non-surgical treatment for periodontal disease using exclusively hand instruments, exclusively ultrasonic instruments or a combination approach. Differences in time efficiency and equipment use with each treatment method were evaluated.Methods In total, 55 patients with periodontitis were treated across two studies (randomised controlled trial and cohort study) with non-surgical periodontal therapy using hand instruments (HI), ultrasonic instruments (UI) or a combination approach (CI). All patients were re-evaluated 90 days after treatment. Clinical parameters, time taken and financial implications of non-surgical periodontal therapy were explored with a descriptive analysis within this post hoc analysis.Results There were no clinically relevant differences in clinical parameters across all groups at day 90. Inter-group comparisons showed no clinically relevant differences in treatment outcome between groups. UI required less time on average to complete treatment compared to HI. UI provided using a half mouth approach had fewest overall episodes of expenditure and lowest maintenance costs.Conclusions Comparison of clinical outcomes between HI, UI and CI yielded no clinically relevant differences. When comparing HI and UI, UI had a shorter treatment time on average. Full mouth treatment was associated with the least patient visits. UI was least costly on a recurring basis.

Current Concepts in the Management of Periodontitis

Periodontitis is a common disorder affecting >40% of adults in the United States. Globally, the severe form of the disease has a prevalence of 11%. In advanced cases, periodontitis leads to tooth loss and reduced quality of life. The aetiology of periodontitis is multifactorial. Subgingival dental biofilm elicits a host inflammatory and immune response, ultimately leading to irreversible destruction of the periodontium (i.e. alveolar bone and periodontal ligament) in a susceptible host. In order to successfully manage periodontitis, dental professionals must understand the pathogenesis, primary aetiology, risk factors, contributing factors and treatment protocols. Careful diagnosis, elimination of the causes and reduction of modifiable risk factors are paramount for successful prevention and treatment of periodontitis. Initial non-surgical periodontal therapy primarily consists of home care review and scaling and root planing. For residual sites with active periodontitis at periodontal re-evaluation, a contemporary regenerative or traditional resective surgical therapy can be utilised. Thereafter, periodontal maintenance therapy at a regular interval and long-term follow-ups are also crucial to the success of the treatment and long-term retention of teeth. The aim of this review is to provide current concepts of diagnosis, prevention and treatment of periodontitis. Both clinical and biological rationales will be discussed.

Treating periodontitis-a systematic review and meta-analysis comparing ultrasonic and manual subgingival scaling at different probing pocket depths

BACKGROUND

Mechanical plaque removal has been commonly accepted to be the basis for periodontal treatment. This study aims to compare the effectiveness of ultrasonic and manual subgingival scaling at different initial probing pocket depths (PPD) in periodontal treatment.

METHODS

English-language databases (PubMed, Cochrane Central Register of Controlled Trials, EMBASE, Medline, and ClinicalTrials.gov, by January, 2019) were searched. Weighted mean differences in primary outcomes, PPD and clinical attachment loss (CAL) reduction, were estimated by random effects model. Secondary outcomes, bleeding on probing (BOP), gingival recession (GR), and post-scaling residual dental calculus, were analyzed by comparing the results of each study. The quality of RCTs was appraised with the Cochrane Collaboration risk of bias tool. The GRADE approach was used to assess quality of evidence.

RESULTS

Ten randomized controlled trials were included out of 1434 identified. Initial PPD and follow-up periods formed subgroups. For 3-months follow-up: (1) too few shallow initial pocket studies available to draw a conclusion; (2) the heterogeneity of medium depth studies was so high that could not be merged to draw a conclusion; (3) deep pocket studies showed no statistical differences in PPD and CAL reduction between ultrasonic and manual groups. For 6-months follow-up: (1) too few shallow initial PPD studies to draw a conclusion; (2) at medium pocket depth, PPD reduction showed manual subgingival scaling better than ultrasound. No statistical differences were observed in CAL reduction between the two approaches; (3) for deep initial PPD studies, both PPD and CAL reduction showed manual subgingival scaling better. GR results indicated no statistical differences at medium and deep initial pocket studies between the two methods. BOP results showed more reduction at deep pocket depths with manual subgingival scaling. No conclusion could be drawn about residual dental calculus.

CONCLUSION

When initial PPD was 4-6 mm, PPD reduction proved manual subgingival scaling was superior, but CAL results showed no statistical differences between the two means. When initial PPD was ≥6 mm, PPD and CAL reductions suggested that manual subgingival scaling was superior.

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.

Nonsurgical and surgical treatment of periodontitis: how many options for one disease?

Treatment of periodontitis aims at preventing further disease progression with the intentions to reduce the risk of tooth loss, minimize symptoms and perception of the disease, possibly restore lost periodontal tissue and provide information on maintaining a healthy periodontium. Therapeutic intervention includes introduction of techniques to change behavior, such as: individually tailored oral-hygiene instructions; a smoking-cessation program; dietary adjustment; subgingival instrumentation to remove plaque and calculus; local and systemic pharmacotherapy; and various types of surgery. No single treatment option has shown superiority, and virtually all types of mechanical periodontal treatment benefit from adjunctive antimicrobial chemotherapy. Periodontal treatment, because of the chronic nature of periodontitis, is a lifelong commitment to intricate oral-hygiene techniques, which, when properly implemented, will minimize the risk of disease initiation and progression.

Detection, removal and prevention of calculus: Literature Review

Dental plaque is considered to be a major etiological factor in the development of periodontal disease. Accordingly, the elimination of supra- and sub-gingival plaque and calculus is the cornerstone of periodontal therapy. Dental calculus is mineralized plaque; because it is porous, it can absorb various toxic products that can damage the periodontal tissues. Hence, calculus should be accurately detected and thoroughly removed for adequate periodontal therapy. Many techniques have been used to identify and remove calculus deposits present on the root surface. The purpose of this review was to compile the various methods and their advantages for the detection and removal of calculus.

Application and development of ultrasonics in dentistry

Since the 1950s, dentistry's ultrasonic instruments have developed rapidly. Because of better visualization, operative convenience, and precise cutting ability, ultrasonic instruments are widely and efficiently applied in the dental field. This article describes the development and improvement of ultrasonic instruments in several dental fields. Although some issues still need clarification, the results of previous studies indicate that ultrasonic instruments have a high potential to become convenient and efficient dental tools and deserve further development.

Microbiological findings after periodontal therapy using curettes, Er:YAG laser, sonic, and ultrasonic scalers

AIM

To evaluate and compare the microbiological effects of hand instruments, Er:YAG-laser, sonic, and ultrasonic scalers in patients with chronic periodontitis. Patient perception of each treatment was documented.

MATERIAL AND METHODS

From 72 patients, bacterial samples were collected from the deepest pocket in each quadrant (total: 288 sites). A polymerase chain reaction kit estimated the amount of Aggregatibacter (Actinobacillus) actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythensis (Tf), and Treponema denticola (Td) at baseline as well as 3 and 6 months after therapy. One quadrant in each patient was randomly assigned to curettes (H-group), Er:YAG laser (L-group), sonic device (S-group), or ultrasonic device (U-group).

RESULTS

Three months post-operatively, the amounts of Pg, Pi, Tf, and Td were significantly reduced in all groups. Laser and sonic instrumentation failed to reduce Aa. Six months after therapy, significant differences were still detected for Pg (L- and U-group), for Pi and Tf (S-group), and for Td (L-, S- and U-group). Patients rated ultrasonic treatment as more preferable than hand and laser instrumentation.

CONCLUSION

The various treatment methods resulted in a comparable reduction of the evaluated periodontal pathogens, and bacterial increase was only partially different 6 months post-operatively. Ultrasonic instrumentation caused less discomfort.

Periodontal healing after non-surgical therapy with a modified sonic scaler: a controlled clinical trial

AIM

The aim of this study was to compare the clinical and microbiological healing outcomes following non-surgical periodontal therapy using a modified sonic scaler system versus scaling and root planing (S/RP) with hand instruments.

MATERIAL AND METHODS

The study comprised 20 chronic periodontitis patients. Using a split-mouth design, both treatment modalities were randomly applied to one quadrant of the upper and lower jaws. Clinical and microbiological parameters were assessed at baseline, 4 weeks, and 6 months after treatment. Furthermore, post-operative hypersensitivity was investigated. The Wilcoxon signed-rank test (alpha = 0.05) was used for statistical analysis.

RESULTS

With both therapy methods, periodontal conditions showed statistically significant clinical and microbiological improvements after 4 weeks and 6 months. Hypersensitive teeth were found only 4 weeks after S/RP. Besides a significantly better bleeding on probing reduction in deep S/RP sites and less time required for root instrumentation by the sonic scaler, no other clinical and microbiological parameters revealed significant differences between sites treated with the sonic scaler or S/RP.

CONCLUSION

The sonic scaler system and S/RP seem to provide similarly favourable periodontal healing results, although in deep pockets S/RP appeared to achieve a better resolution of inflammation.

A laboratory study to determine the effects of universal and rotating ultrasonic inserts on wrist movement and scaling time efficiency of dental hygienists

PURPOSE

The purpose of this study was to determine if differences existed in range of wrist movements and scaling time efficiency of dental hygienists using a rotating ultrasonic insert when compared with a standard universal insert.

METHODS

A convenience sample of 32 consenting experienced dental hygienists who met inclusion criteria was invited to participate. Using a cross-over research design, the 32 participants were randomly assigned to one of the two subgroups. Subgroup A (n = 16) used the rotating universal ultrasonic insert on a typodont, rested for 15 min and the standard universal insert on a different typodont. Subgroup B (n = 16) used the standard universal ultrasonic insert on a typodont, rested for 15 min and the rotating universal ultrasonic insert on a different typodont. Each participant used the rotating and standard universal ultrasonic scaling inserts to remove 2 cm3 artificial calculus from two different typodonts for up to 15 min per insert. Scaling time efficiency was determined using a Modified Volpe-Manhold Calculus Index, measuring the amount of artificial calculus remaining after ultrasonic scaling. While scaling, each participant wore the WristSensor goniometry gloves, which determined changes in wrist movements (flexion and extension and ulnar and radial deviations), measured as a deviation from the neutral position.

RESULTS

A paired t-test (P = 0.05) using 30 subjects with useable data, revealed no statistically significant differences between the two different inserts in terms of wrist movements and scaling time efficiency. A multivariate analysis of variance revealed no statistically significant differences in the percentage of time dental hygienists were in high, medium or low-risk posture categories while using the rotating ultrasonic insert compared with the standard universal insert. Based on the results of this laboratory study, dental hygienists using a rotating ultrasonic insert appear to experience no ergonomic advantage in terms of wrist postures or timesavings over a standard insert.

Comparative clinical responses related to the use of various periodontal instrumentation

AIM

The aim of this study was to evaluate in vivo the effectiveness of scaling and root planing of a power-driven mechanism compared with hand instruments and ultrasonic insert alone with a split-mouth design after 3 and 6 months.

METHODS

Healing events after initial periodontal therapy were investigated in 20 patients with moderate-to-severe adult periodontitis. Plaque index (PlI), bleeding on probing (PBI), probing pocket depth (PPD), probing attachment level (PAL) and number of moderate and deep pockets (NMP, NDP) were recorded at baseline and 3 and 6 months after treatment. Oral hygiene instruction was provided for each patient. Randomly assigned quadrants per patient were scaled and root planed with hand instrumentation (curettes, hoes and files), with reciprocating power-driven instruments, with ultrasonic scaler alone and with the combined use of ultrasonic scaler and power-driven inserts. The Friedman test was applied to test the significance of difference between the various methods of root instrumentation. Repeated measures of analysis of variance (manova) were used to analyse the time effect on the different treatments.

RESULTS

At the 6-month evaluation, all groups in the scaling and root planing treatment presented with an improvement in the measured clinical parameters, as compared with baseline. No statistical differences (p>0.05) were observed in the assessed periodontal indices among the study sites between the four groups for either treatment.

CONCLUSIONS

Under our experimental conditions, this clinical study demonstrates that mechanized root planing with power-driven instruments, as effective as the usual procedures (hand and sonic instruments), represents a satisfactory and alternative means of nonsurgical root therapy.

Local Anti-Infective Therapy: Mechanical and Physical Approaches. A Systematic Review

BACKGROUND

Although mechanical non-surgical therapy (scaling and root planing) is the most common means of initial treatment of periodontal diseases, the relative clinical efficacy of various methods, including manual versus machine-driven, with or without adjunctive agents, has not been determined.

RATIONALE

This systematic review analyzes the literature in an effort to identify the most effective therapies, based on both clinical and patient-centered outcomes.

FOCUSED QUESTION

In patients with periodontitis, what is the effect of mechanically-driven instrumentation (e.g., power-driven) and/or subgingival irrigation with and without manual instrumentation compared to manual instrumentation alone?

SEARCH PROTOCOL

Two investigators examined MEDLINE and the Cochrane Oral Health Group specialized registry for clinical trials published in English. Hand searches were performed of the International Journal of Periodontics & Restorative Dentistry, Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research. Searches were performed for articles published through April 2002. Editors of these journals were asked to provide information on articles currently under review. In addition, an electronic discussion group on periodontal diseases and treatment was contacted, as were manufacturers of manual and mechanical instruments and of adjunctive agents.

SELECTION CRITERIA

INCLUSION CRITERIA

Only randomized clinical trials, cohort studies, or case-control studies at least 3 months long were included. All studies had to compare manual instrumentation (MI; scaling and root planing [SRP]) alone with some other form of non-surgical therapy. These included MI versus mechanically-driven instruments (MDI) alone; MI versus MI plus MDI; MI versus MDI plus an agent (e.g., chlorhexidine); and MI versus subgingival irrigation (SGI) delivered in conjunction with MI or MDI.

EXCLUSION CRITERIA

Studies not meeting the inclusion criteria or those treating periodontal diseases as a manifestation or complication of some other disease or disorder were not included.

DATA COLLECTION AND ANALYSIS

Probing depth, clinical attachment level, bleeding on probing, and gingival recession were the primary outcomes. Because of the heterogeneity of the patient populations, treatments, and outcome measures, meta-analysis was not appropriate. Only in-study data were compared. Four of the studies required extrapolating data from figures and graphs, resulting in questionable accuracy.

MAIN RESULTS

1. Nine studies, representing a study population of 129, were included in the review. 2. Five studies compared MI with MDI alone. The other 4 compared MI alone to MI plus SGI or subgingival tissue treatment. 3. There was comparable efficacy between MI and MDI when treating single-rooted teeth. 4. The use of SGI or subgingival tissue treatment as an adjunct to MI provided no additional benefit compared to MI alone. 5. Findings reported in the review must be interpreted with considerable caution, as lack of study heterogeneity made meta-analysis unfeasible and the need to extrapolate outcomes values from graphs and figures may have resulted in some inaccuracy.

REVIEWERS' CONCLUSIONS

1. Manual and mechanically-driven instrumentation appears comparable in affecting improved clinical outcomes. 2. Instrumentation time for MI and MDI were similar, except for 1 study in which MDI was significantly shorter. 3. Adjunctive SGI plus MI and subgingival tissue treatment result in similar clinical outcomes when compared to MI alone. 4. If study data are to be effectively and analytically combined to facilitate meaningful comparisons of treatment outcomes, detailed and standardized study designs must be developed and used consistently in clinical trials.

Position PaperPeriodontal Maintenance

The purpose of this paper is to provide an overview of the role of periodontal maintenance procedures in the treatment of periodontal diseases. Reliance on this position paper in patient management will not guarantee a successful outcome, as periodontal diseases typically involve complex causes and symptoms. Ultimately, decisions regarding the diagnosis, treatment, and management of disease, as well as subsequent preventive therapy, must be made by the treating practitioner based on specific circumstances presented by the patient.

A systematic review of efficacy of machine-driven and manual subgingival debridement in the treatment of chronic periodontitis

OBJECTIVES

The purpose of this systematic review was to determine the efficacy of machine-driven compared with manual subgingival debridement in the treatment of periodontitis.

BACKGROUND

Mechanical debridement of the periodontal pocket plays a pivotal role in the treatment of periodontitis.

METHODS

A literature search for controlled clinical trials with at least 6 months' follow-up comparing machine-driven instruments with hand instruments for the treatment of chronic periodontitis was performed up to April 2001. Screening of titles and abstracts as well as data extraction was conducted independently by two reviewers (J.T. & T.F.F.). As primary outcome variable, the prevention of tooth loss was used; secondary outcome variables were the prevention of disease progression, the resolution of anatomical defects and the resolution of gingival inflammation. Efficiency was assessed by mean time needed to treat one tooth.

RESULTS

From a total of 419 abstracts, 27 articles were included for the review. The weighted kappa score for agreement between the two reviewers was 0.77, 95% CI: 0.65-0.89, indicating substantial agreement. No study reported on the selected primary outcome variables. Using clinical attachment gain, probing pocket depth reduction or bleeding on probing reduction as outcome variables, there appeared to be no differences between ultrasonic/sonic and manual debridement. No major differences in the frequency or severity of adverse effects were found. However no meta-analysis could be performed on any of the previously mentioned parameters. Ultrasonic/sonic debridement was found to take significantly less time, i.e. 36.6%, than debridement using hand instruments (P = 0.0002, 95% CI of the standardized effect estimate: 0.39-1.37, heterogeneity P = 0.77).

CONCLUSIONS

With respect to clinical outcome measures, the available data do not indicate a difference between ultrasonic/sonic and manual debridement in the treatment of chronic periodontitis for single-rooted teeth; however, the evidence for this is not very strong. In addition, ultrasonic/sonic subgingival debridement requires less time than hand instrumentation. Further research is needed to assess the efficacy of machine-driven debridement on multirooted teeth and clinical outcome variables having tangible benefit to the patients should be used.

Clinical significance of non-surgical periodontal therapy: an evidence-based perspective of scaling and root planing

Analysis of Egyptian hieroglyphics and medical papyri indicate that non-surgical periodontal treatment was common 3000-4000 years ago. Even today, scaling and root planing (SRP) remains an essential part of successful periodontal therapy. The collective evidence from numerous clinical trials reveals a consistency of clinical response in the treatment of chronic periodontitis by SRP using manual, sonic, or ultrasonic instrumentation. Thus, SRP remains the 'gold standard' to which more recently developed therapeutic modalities must be compared. Inherent to the clinical evaluation of SRP are such concerns as manual versus sonic and ultrasonic instrumentation, control of sub-gingival bacterial populations, removal of calculus, root smoothness and changes in various clinical parameters, e.g. probing depth, attachment levels, bleeding on probing and gingival inflammation. Lastly, an abbreviated discussion is presented on a relatively new paradigm of complete mouth 'disinfection' in a compressed time-frame that includes SRP as a significant component of the treatment regimen.

In vivo ultrasonic debridement forces in bicuspids: a pilot study

BACKGROUND

Hand instruments lead to application of excessive forces, resulting in extensive root substance removal. Ultrasonic debridement primarily removes accretions from root surfaces. However, there is a lack of information on procedural aspects of ultrasonic debridement. The purpose of the present study was to assess the forces applied by different therapists during ultrasonic root surface debridement of bicuspids in periodontal patients in vivo.

METHODS

Ten dentists and 10 dental hygienists each debrided 1 aspect of a bicuspid with moderate chronic periodontitis using an ultrasonic curet. The forces applied were recorded using a piezo-electric receiver built into the handle of the ultrasonic curet, an electronic transducer, and an analogous writer. The force recordings were converted from millivolts into Newtons (N). Mean positive and negative forces were calculated for each therapist, and t tests were used to assess differences in these forces between dentists and dental hygienists.

RESULTS

The results showed that the mean positive force applied by dentists was 1.00 N (range 0.53 to 1.34 N). The corresponding mean value for dental hygienists was 0.77 N (range 0.20 to 1.22 N). The mean root debridement time was 110.2 seconds (range 38 to 165 seconds) for dentists and 90.8 seconds (range 38 to 244 seconds) for dental hygienists. The mean percentage of total debridement time used for positive force application by dentists was 76.1%, and for dental hygienists 63.9%. Negative forces impacting on the periodontal soft tissues were also recorded. These negative forces reached a mean of 0.16 N for dentists and 0.31 N for dental hygienists.

CONCLUSIONS

From these observations, it may be concluded that application of ultrasonic debridement therapy is highly subjective, and that dentists and dental hygienists may not be adequately trained to use these instruments optimally.

Clinical comparison of the effectiveness of novel sonic instruments and curettes for periodontal debridement after 2 months

AIM

The aim of this study was to evaluate in vivo the effectiveness of scaling and root planing of new oscillating instruments (Periosonic) using a sonic handpiece compared to hand curettes with a split mouth design after 2 months.

METHODS

11 patients with adult periodontitis participated in this study. Plaque index (PII) (O'Leary), bleeding on probing (BOP), probing pocket depth (PPD), recession (REC) and clinical attachment level (CAL) were recorded at baseline and 2 months after treatment. After oral hygiene instruction, 2 randomly assigned quadrants per patient were scaled and root planed with curettes (control side) and the remaining 2 quadrants with the Periosonic instruments 1 and 2 (test side). The student t-test for paired data was used to test the significance of difference between test and control sides.

RESULTS

There was no statistical difference (p>0.05) between the 2 sides for the improvement of the clinical parameters excepted for the group with initial PPD of 4-6 mm (test: 1.3+/-0.4 mm PPD reduction, control: 1.6+/-0.4 mm). For PPD > or =7 mm, the test side had better clinical improvement in attachment levels (2.2+/-0.9 mm), less recession (-0.4+/-0.5 mm) with lower PPD reduction (2.4+/-0.6 mm) than the control side (AL: 1.6+/-1.8 mm; REC: -1.3+/-0.7 mm, PPD reduction: 3.0+/-1.4 mm).

CONCLUSION

This clinical study demonstrated that Periosonic(R) instruments are clinically at least as effective as curettes in PPD reduction when initial PPD is < or =6 mm and show better clinical attachment level improvement with less recession for initial PPD of > or =7 mm.

A comparative in vitro study of a magnetostrictive and a piezoelectric ultrasonic scaling instrument

BACKGROUND

The effects of magnetostrictive ultrasonic instruments and piezoelectric ultrasonic instruments on tooth surfaces seem to differ with regards to root debridement.

AIM

The purpose of this study was to compare a magnetostrictive ultrasonic scaling instrument with a piezoelectric ultrasonic scaling instrument and a hand curette regarding time taken, calculus removal, tooth surface roughness (Ra), and SEM examination before and after instrumentation.

METHODS

30 extracted human teeth with subgingival calculus were assigned to one of three treatment groups (n=10). The working force was standardised for both ultrasonic instruments at 200 g and for the curette at 500 g.

RESULTS

The results revealed that the time needed for instrumentation was 126.1+/-38.2 s for the curette, significantly more than for the piezoelectric ultrasonic instrument (74.1+/-27.6 s; p<0.05) and 104.9+/-25.4 s for the magnetostrictive ultrasonic instrument. Remaining calculus was similar for all three groups. The end Ra values were significantly worse for the piezoelectric instrument (2.02+/-0.41; p<0.05) compared to 1.42+/-0.48 for the curette and 1.36+/-0.41 for the magnetostrictive instrument. The SEM examination revealed the smoothest surfaces but, subjectively, the most tooth substance loss after the curette, followed by the magnetostrictive instrument, with the least substance loss, and then the piezoelectric instrument, with medium substance loss.

CONCLUSION

The piezoelectric ultrasonic scaler was more efficient than the magnetostrictive ultrasonic scaler in removing calculus but left the instrumented tooth surface rougher.

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

Ultrasonic and sonic scalers appear to attain similar results as hand instruments for removing plaque, calculus, and endotoxin. Ultrasonic scalers used at medium power seem to produce less root surface damage than hand or sonic scalers. Due to instrument width, furcations may be more accessible using ultrasonic or sonic scalers than manual scalers. It is not clear whether root surface roughness is more or less pronounced following power-driven scalers or manual scalers. It is also unclear if root surface roughness affects long-term wound healing. Periodontal scaling and root planing includes thorough calculus removal, but complete cementum removal should not be a goal of periodontal therapy. Studies have established that endotoxin is weakly adsorbed to the root surface, and can be easily removed with light, overlapping strokes with an ultrasonic scaler. A significant disadvantage of power-driven scalers is the production of contaminated aerosols. Because ultrasonics and sonics produce aerosols, additional care is required to achieve and maintain good infection control when incorporating these instrumentation techniques into dental practice. Preliminary evidence suggests that the addition of certain antimicrobials to the lavage during ultrasonic instrumentation may be of minimal clinical benefit. However, more randomized controlled clinical trials need to be conducted over longer periods of time to better understand the long-term benefits of ultrasonic and sonic debridement.

Root substance removal with Er:YAG laser radiation at different parameters using a new delivery system

BACKGROUND

The recently introduced Er:YAG laser radiation appears to be a promising alternative in treating dental hard tissue due to its thermo-mechanical ablation properties and the lack of thermal side effects. The present in vitro study attempted to evaluate the use of Er:YAG laser radiation in combination with a specially developed delivery system in removing calculus from root surfaces.

METHODS

Fifty extracted anterior teeth, premolars and molars, were divided into 2 groups of 25 each with (group A) and without (group B) subgingival calculus. Source of radiation was an Er:YAG laser device with a wavelength of 2.94 microm, in the infrared optical spectrum, a pulse duration of 250 ns, and a pulse repetition rate of 15 pps. In each group, 6 teeth were irradiated with 300 laser pulses either at 60 mJ, 80 mJ, 100 mJ, or 150 mJ. The samples were continually moved linearly using a computer numeric controlled device. The volumetric evaluation of root substance removal was performed with a 3-dimensional laser scanning system (100,000 surface points per sample, accuracy: 5 microm) and special image analyzing software. A scanning electron microscopic (SEM) observation was performed to assess the laser induced ultrastructural changes on the root surfaces. Statistical analysis was carried out with ANOVA followed by the Scheff*e test and with regression analysis according to Pearson-Bravais at a level of significance of 5% (P <0.05).

RESULTS

The linear measurement of substance removal on calculus samples (group A) revealed average depths between 174.38 (+/-16.13) microm and 501.85 (+/-111.01) microm. Defect depths on the teeth without calculus (group B) ranged from 37.78 (+/-14.03) microm to 484.44 (+/-80.63) microm. The SEM observation of laser-treated root surfaces revealed no signs of thermal damage; e.g., melting, fusion, or cracking.

CONCLUSIONS

The results of the present study showed that a substance removal with Er:YAG laser radiation at lower energy densities is comparable, in effect, to that after conventional root surface instrumentation with curets. The results seem to indicate that calculus removal can be selectively done using lower radiation energies. Considering the favorable results of the SEM investigation, the use of the Er:YAG laser in periodontal therapy may be possible in the future.

Acoustic microstreaming: detection and measurement around ultrasonic scalers

BACKGROUND

Acoustic microstreaming (AMS) may be useful to the clinician when using the ultrasonic scaler to remove particulate matter from the teeth. The aim of this study was to detect and measure the effects of AMS produced by ultrasonic scalers.

METHODS

For the study, an ultrasonic generator was selected with 4 differently shaped scaling tip inserts (TFI-3, TFI-9, TFI-1, and P-12). A plaque substitute (0.2 mm thick soft cream cheese) was coated onto a microscope slide and immersed in water. The ultrasonic scaler tip was placed in the water and orientated either perpendicular or parallel to the slide. The instrument was operated both contacting the slide under a load of 0.3 N and non-contacting at various distances from the slide surface. This was repeated with the tip parallel to the slide. The area of medium removed was quantified by digital image analysis.

RESULTS

It was found that AMS removed the plaque substitute from around the tip. The TFI-9 insert significantly removed more material with increasing displacement amplitude (P <0.05). Significantly larger areas of plaque substitute were removed when the tips of the TFI-3, TFI-9, and P-12 inserts were orientated perpendicularly to the slide compared to the parallel orientation (P <0.05). Of the 4 inserts used, the TFI-9 insert removed the most material while the straight tip produced no apparent removal. Removal by AMS required the presence of a water medium and such forces were found to decrease with distance from the scaling tip. No plaque substitute removal was seen at a distance of 7 mm for the TFI-9 insert at 37.5 microm displacement with the tip orientation parallel to the slide.

CONCLUSIONS

It is concluded that AMS occurs around ultrasonic scalers and this depends on the displacement amplitude, tip orientation, and presence of a water medium. AMS may play a role in disruption of subgingival biofilms associated with periodontal disease.

Environmental effects on the growth and proteolysis of Treponema denticola ATCC 33520

The effect of pH, redox potential, O2 and H2 on the growth and proteolytic activity of Treponema denticola ATCC 33520 was studied in a chemostat at different growth rates. The peptidase and protease activities were estimated using different amido-methyl coumarin derivatives and azocasein. The maximum growth rate of T. denticola ATCC 33520 was 0.14 h-1. Reduction of the growth rate of T. denticola by 50-60% gave: an increase in cell mass of 150-200%, a higher acetogenesis and a shift of the pH optimum. The protease and phenylalanine peptidase activities seemed to be of greater importance for the growth of T. denticola ATCC 33520 than the rather low arginine and proline peptidase activities. The redox potential (Eh) played a secondary role. At microaerophilic conditions with 1-5% O2, the cultures maintained a redox potential below -311 mV and an optimal acetogenesis. The presence of H2 induced a marked growth stimulation of T. denticola ATCC 33520. It is concluded that the cell mass and proteolytic activity of T. denticola ATCC 33520 are modulated by the growth rate and the pH and to a lesser extend by the redox potential and presence of O2. Stagnation of the exudate-flow influences these factors and will lead to an increase of the spirochetal population and proteolysis in the periodontal pocket.

The bactericidal effects of dental ultrasound on Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. An in vitro investigation

This study investigated the possible bactericidal acoustic effects of the dental ultrasonic scaler. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis suspensions, were subjected to the vibrations of a Cavitron P1 insert for 2.5 and 5.0 min in an acoustically-simulated pocket model and the survivors enumerated. The extent of any cavitation occurring within the pocket model to which the statistically significant bactericidal activity observed might be attributed, was determined by 'sonoluminescence', which was then investigated by photomultiplication techniques. However, these failed to detect any sonoluminescence within the pocket space and, moreover, the necessary deflection of the water coolant away from the insert tip, to avoid flooding of the experimental pocket, proved to result in temperatures of 47.6 degrees C and 52.3 degrees C at the respective time intervals, and thereby constituted an alternative possible bactericidal mechanism. Examination of the effects of such temperature changes on the target bacteria then revealed statistically significant differences in the viable counts of both microorganisms after 5.0-min periods, and as such were comparable to those previously detected in relation to the pocket model. Whilst it must be presumed that the bacteriolytic effect observed in the main investigation was due to the incidental temperature changes, in the absence of acoustic cavitation the influence of any associated acoustic microstreaming cannot be discounted. Further investigations to assess the bactericidal potential of acoustic phenomena using a modified experimental to exclude any hyperthermic effects are therefore necessary.

Microbiological response to mechanical treatment in combination with adjunctive therapy. A review of the literature

The recognition of the microbial origin and the specificity of periodontal infections has resulted in the development of several adjunctive therapies (antibiotics and/or antiseptics) to scaling and root planing in the treatment of chronic adult periodontitis. This article aims to review the "additional" effect of a subgingival irrigation with chlorhexidine, or a local or systemic application of tetracycline or metronidazole, performed in combination with a single course of scaling and root planing in patients with chronic adult periodontitis. All treatment modalities are compared with scaling and root planing, based on their impact on: the probing depth (PD); total number of colony forming units per ml (CFU/ml); the proportions and/or the detection-frequency of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia; and/or on the percentages of cocci, spirochetes, motile, and other micro-organisms on dark field microscopy examination. All treatment modalities, including scaling and root planing without additional chemical therapy, resulted in significant reductions in the probing depth and the proportions of periodontopathogens, at least during the first 8 weeks post-therapy. However in comparison to a single course of scaling and root planing, the supplementary effect of adjunctive therapies seems to be limited. In general, only the irrigation with chlorhexidine 2%, the local application of minocycline, and the systemic use of metronidazole (in case of large proportions of spirochetes) or doxycycline (in case of large proportions of A. actinomycetemcomitans) seem to result in a prolonged supplementary effect when compared to scaling and root planing. Therefore, the use of antibiotics on a routine basis, especially in a systemic way, in the treatment of chronic adult periodontitis, can no longer be advocated, considering the increasing danger for the development of microbial resistance.

A comparative study of a surgical method and scaling and root planing using the Odontoson

This investigation compared a traditional periodontal surgical method with a non-surgical treatment of scaling and root planing by an ultrasonic device (Odontoson M) using irrigation with an iodised solution. 8 adult patients with periodontal disease were each treated at 2 randomly chosen quadrants by a Widman flap type surgical technique, and the remaining non-surgically. The patients then attended bi-monthly oral hygiene sessions over a period of 1 year. At that stage, clinical evaluation revealed that the Odontoson M plus an ionized irrigant solution achieved a statistically comparable outcome to that of surgical treatment, even in the pockets initially up to 7 mm in depth.

Development of a gene transfer system in Treponema denticola by electroporation

Treponema denticola is strongly implicated in the etiology of periodontal diseases. However, genetic transformation of this organism has not been reported. We now demonstrate a gene transfer system in T. denticola by electroporation using a broad host plasmid pKT210 as a shuttle vector. Plasmid extraction, Southern blot hybridization as well as the polymerase chain reaction indicated the presence of the plasmid in T. denticola transformants. The restriction patterns of plasmid pKT210 rescued from the T. denticola transformants in Escherichea coli suggested that some of the rescued plasmids were identical to the original pKT210, but some of them had been modified. This transformation system could be a potentially useful tool for genetic manipulation of oral spirochetes.

Cloning and sequence analysis of a chymotrypsinlike protease from Treponema denticola

A clone expressing a Treponema denticola chymotrypsinlike protease from recombinant plasmid pSA2 was identified in a genomic library of T. denticola ATCC 35405. Nucleotide sequencing of the insert identified an open reading frame, designated the prtB gene, which codes for the protease. Two potential inverted repeat sequences are present both upstream and downstream from the prtB gene. The prtB gene would code for a putative protein of 273 amino acids with a calculated molecular mass of 30.4 kDa and an estimated pI of 7.0. The G+C content of the gene is 40.3%. The results of maxicell analysis are consistent with the expression of a 30-kDa protease from the prtB gene. Preliminary characterization of the protease indicated that it was inhibited by the protease inhibitors phenylmethylsulfonyl fluoride, diisopropylfluorophosphate, and N-tosyl-L-phenylalanine chloromethyl ketone but not by N alpha-p-tosyl-L-lysine chloromethyl ketone. Purification of the protease was accomplished with the PinPoint protein purification system following construction of site-directed mutagenized plasmid pXa-3:2. The purified protease degraded human and bovine serum albumins as well as casein. Furthermore, hemolysis of sheep erythrocytes by the protease was observed. Northern (RNA) blot analysis of mRNA extracted from strain 35405 indicated a single 1.9-kb mRNA species containing the prtB transcript. In addition, the results of primer extension analysis indicated that transcription was initiated primarily at a T residue. However, no corresponding -10 and -35 sequences related to Escherichia coli promoter sequences were identified. The availability of the purified protein and its gene will aid in evaluating the potential role of the protease in the physiology and virulence of T. denticola since proteases may play a key role in oral treponemal pathogenicity.

The periodontally-involved root surface

Recent years have seen much research on the periodontally-involved root surface. Many of these studies have produced results which suggest that plaque contaminants of the root surface are only superficially placed, and capable of being removed by gentle means. Further research has attested to the difficulties in rendering periodontally-involved root surfaces free of calculus deposits by instrumentation, yet clinical studies show that periodontal disease can be managed by root planing. It is concluded that root surface debridement is best assessed on the basis of the healing response and that it should aim to disrupt plaque on and remove plaque from the periodontally-involved root surface rather than to remove part of the root surface itself.

Effects of ultrasonic and sonic scalers on dental plaque microflora in vitro and in vivo

The effects of ultrasonic and sonic scalers on the subgingival microflora were investigated in vitro and in vivo. In the in vitro investigation, 27 plaque samples collected from periodontal pockets were submitted to ultrasonic and sonic vibrations for 10, 30 and 60 s. Bacterial suspensions were examined by darkfield microscopy to detect qualitative changes and cultured to evaluate the total number of cultivable bacteria. Microscopic counts following both instrumentations showed a decrease in the proportions of spirochetes and motile rods and an increase in the % of coccoids and rods. The changes were directly related to the time-period of instrumentation. Comparison between both types of instrumentation showed significant differences and more pronounced changes were observed with the ultrasonic than the sonic scaler. Spirochetes and motile rods were reduced to approximately 0.1% after ultrasonic treatment versus 24.7% after sonic instrumentation. Cultural observations showed a marked increase in total number of colony-forming units following both treatments. The clinical investigation included 66 periodontal pockets which were instrumented subgingivally for 10 and 30 s with ultrasonic or sonic scalers. Qualitative changes were similar to those observed in vitro, i.e., reduction in spirochete and motile rod counts as well as the other morphotypes with an increase in coccoid cells. Total counts of bacteria were reduced following debridement. No difference in the microscopic or cultural data was found between ultrasonic and sonic instrumentation.

Hemagglutination activity of Treponema denticola grown in serum-free medium in continuous culture

Hemagglutination by different Treponema denticola strains was observed for erythrocytes of human, horse, bovine, and rabbit origin. The growth of T. denticola ATCC 33520 in serum-free medium in continuous culture enabled us to study the hemagglutinating activity of freshly harvested spirochetes of a defined physiological status. The hemagglutinating activity was cell bound and not related to motility or appendages, such as fimbriae. The activity was destroyed by proteolytic enzymes, heat, and alkylation, indicating that the agglutinin is of a proteinaceous nature. In addition, periodate oxidation of the spirochetes indicated the involvement of carbohydrate groups. Microscopic inspection of the hemagglutination mixtures at the titration endpoints revealed that only a part of the spirochete population was involved in the hemagglutination process. The hemagglutinating activity was found to be growth phase related. The activity was blocked by serum, while of all tested amino acids and carbohydrates, only sialic acid blocked the activity at low concentrations. In conclusion, we found a hemagglutinating activity in T. denticola which was cell bound and growth phase related. The agglutinin may be a glycoprotein, like lectin, that recognizes sialic acid as a receptor.

The effect of hygiene instruments on dentin surfaces: scanning electron microscopic observations

The present study consists of two separate parts. The first section is an in vitro evaluation of the relative abrasiveness of some hygiene instrumentations commonly used during maintenance therapy. In the second section, one of the instruments, a recently developed plastic tip for use on a sonic scaler, was examined for its ability to remove dental plaque from root surface specimens instead for 5 weeks in the oral cavities of dogs. The in vitro study was performed on recently obtained dentin specimens where a ridge had been machined parallel to the long axis of the tooth. The sonic scaler fitted with the plastic tip gave considerably less removal of dentin and a smoother dentin surface than the curet, the rubber cup with polishing paste, or the sonic scaler with an ordinary metal tip. These findings further demonstrated that the plastic tip was able to efficiently remove 5-week old dental plaque from experimental root surface areas within a time frame of 5 seconds. The new plastic tip may be valuable in maintenance therapy giving less risks for iatrogenic effects on the root surfaces than other debridement methods.

Comparison of the antimicrobial effect of the application of chlorhexidine gel, amine fluoride gel and stannous fluoride gel in debrided periodontal pockets

The clinical and microbiological effect of locally-applied chlorhexidine gel 2%, amine fluoride gel 1.25%, stannous fluoride gel 4% or placebo gel in 40 periodontal pockets of 10 patients were studied. The gels were applied 3 x within 10 min. after mechanical debridement of the pockets. The treatment effect on the subgingival microflora was evaluated by microscopic and culture studies of the subgingival plaque samples. In addition, supragingival plaque, bleeding after probing and probing pocket depth were scored. Examination were carried out before and during a period of 36 weeks after treatment. At the start, the cultured microflora consisted mainly of anaerobic Gram-positive bacteria. Following treatment, the clinical parameters were significantly reduced. Concomitantly, the %s of spirochetes, motile rods and non-motile rods decreased significantly. A significant decrease was also found in the total anaerobic count, whereas the facultative counts remained at the same level found before treatment. This suggested that the treatment resulted in a mainly facultative subgingival microflora. The % Gram-negative rods showed a significant reduction after treatment, but returned to base line at week 12. Statistical analysis of the bacteriological and clinical examinations failed to demonstrate any significant differences between the 4 treatment groups. Thus, in comparison to the placebo gel, subgingival application of chlorhexidine gel 2%, amine fluoride gel 1.25% or stannous fluoride gel 4% did not augment the effect of mechanical debridement on bacteriological and clinical parameters during the experimental period of 36 weeks. However the indicated treatments resulted in a facultative subgingival microflora which is compatible with the host.

Short-term bactericidal activity of chlorhexidine gel, stannous fluoride gel and amine fluoride gel tested in periodontal pockets

The short-term bactericidal effect of 2% chlorhexidine gel, 4% stannous fluoride gel or amine fluoride gel containing 1.25% fluoride on the subgingival microflora was determined in 40 periodontal pockets of 10 patients. The antimicrobial gels or placebo gel were applied in 5-9 mm deep periodontal pockets 3 times within 10 min. Before and 30 min after the applications, samples were taken of the subgingival microflora for determination of the total number of bacteria as well as the number of black pigmented Bacteroides. Reductions of the total number of bacteria were found in all test groups. The reductions found in the pockets treated with chlorhexidine gel or stannous fluoride gel were significantly greater than the reduction found in the pockets treated with a placebo gel. A significant reduction of black-pigmented Bacteroides was found after treatment with chlorhexidine gel or amine fluoride gel. It is concluded that 2% chlorhexidine gel or 4% stannous fluoride gel has a more than 99% reduction effect on the microflora of periodontal pockets within 30 min after application.

The assessment of ultrasonic root surface debridement by determination of residual endotoxin levels

Recent demonstrations of the superficial nature and ease of removal of root-surface-associated cytotoxic materials suggest that extensive root-surface instrumentation is not warranted clinically. This in vitro investigation determined the detoxifying effects of a conservative regime of ultrasonic root debridement, using the Limulus amoebocyte lysate assay for lipopolysaccharide (LPS) as an indication of the presence or absence of cytotoxic materials. 20 extracted periodontally-involved single-rooted teeth, with no clinically detectable calculus deposits, were debrided with a Cavitron TF-10 tip. Light pressure, resulting from a force application of approximately 50 g, lasting for 0.8 s/mm2 of root surface was used and complete overlapping instrumentation ensured. The finding of LPS levels of less than 2.5 ng per root in 19 out of 20 teeth after such debridement was comparable to LPS levels found on healthy, uninvolved control teeth, and thus endorses the growing belief that root surface cleanliness can be readily achieved.

A clinical and microbiological comparison of the effects of water and 0.02% chlorhexidine as coolants during ultrasonic scaling and root planing

The maxillary teeth of 10 patients with moderately advanced chronic periodontitis were treated in a split-mouth design study. The baseline examination included plaque and bleeding scores, probing depths and probing attachment levels. 2 sites in each quadrant were selected for dark-field microscopic analysis. Each quadrant was randomly assigned to test or control and instrumented with an ultrasonic scaler using either 0.02% chlorhexidine or water as the coolant. Measurements were repeated 2, 6 and 10 weeks later, together with additional plaque sampling. Ultrasonic instrumentation with either chlorhexidine or water was equally effective in reducing bleeding scores and improving probing attachment levels. 42% of chlorhexidine- and 38.7% of water-treated sites showed gains of 1 mm or more in clinical attachment. Mean reductions in probing depth were similar (0.9 mm chlorhexidine, and 0.8 mm water). At the final examination, the chlorhexidine-treated quadrants had significantly more sites with probing depths in the 1-3 mm category and less in the greater than 3 mm category than the control quadrants (P less than 0.05). Both treatments reduced the microscopic counts of motiles and spirochaetes, resulting in a subgingival microbiota consistent with periodontal health. The results indicate that chlorhexidine has a slight adjunctive effect in the reduction of pocket depth when used as a coolant during ultrasonic root planing for the treatment of chronic periodontitis.