Efficacy of 5 machining instruments in scaling of molar furcations

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Retrospective analysis of the long-term effect of subgingival air polishing in supportive periodontal therapy

AIM

Glycine powder air polishing (GPAP) procedure has become popular. Aim of the analysis was to compare the clinical outcomes during supportive periodontal therapy (SPT) of subgingival application of GPAP with those using sole conventional mechanical debridement (SC).

MATERIAL AND METHODS

Over a median SPT period of 5.3 years (re-evaluation through last observation), the GPAP cohort (n = 263) received supra- and subgingival biofilm removal with GPAP. Supragingival calculus was removed using curets and sonic scalers here. Patients in the SC cohort (n = 264) were treated with sonic scalers, curets and rubber cup polishing only. Changes in, that is pocket probing depth (PPD) and furcation involvement were assessed retrospectively. A bootstrapping equivalence testing method in line with the principle of the two one-sided tests (TOST) procedure was used to compare clinical outcomes.

RESULTS

The GPAP procedure was statistically equivalent to SC regarding the number of sites with stable PPDs (83.3%; IQR 68.8%, 91.0% vs. 84.0%; IQR 77.8%, 90.0%). However, in the GPAP cohort, a trend towards deterioration in furcation status (no equivalence) was noted.

CONCLUSIONS

In periodontal maintenance, the use of GPAP instead of mechanical plaque removal does not improve the clinical outcome. It seems to be contraindicated to treat furcation defects with GPAP only.

Success of non-surgical periodontal therapy in adult periodontitis patients: A retrospective analysis

Objective

To evaluate the results of active non‐surgical treatment in patients diagnosed with adult periodontitis treated in a specialized clinic for periodontology.

Material & Methods

In total, 1182 patients with adult periodontitis received active non‐surgical therapy, which involved professional oral hygiene instruction, scaling and root planing, supragingival polishing and elective systemic antimicrobial medication. The results of this therapy were based on a full‐mouth periodontal chart as assessed at the time of evaluation. Successful treatment as periodontal pocket depth (PPD) ≤5 mm was the main outcome parameter with bleeding on pocket probing as secondary outcome. Patient‐related factors such as smoking and severity of periodontitis at baseline and site‐related factors such as tooth type, furcation involvement and endodontic treatment were analysed. Possible relations with assessed parameters and the success of active periodontal therapy were evaluated.

Results

Overall 39% of the patients reached the successful treatment objective and a mean bleeding on pocket probing tendency of 14%. Treatment success appeared to be dependent on tooth type where the results at single‐rooted front teeth (85%) and premolar teeth (78%) were more successful than at molar teeth (47%). Analysis revealed that in 55% of the cases furcation involvement at molars was associated with the absence of success. Endodontic treatment was associated with absence of success in 8%‐11% of the cases. Smoking negatively influences successful treatment outcome (P < 0.001).

Conclusion

Active non‐surgical periodontal therapy in patients with adult periodontitis resulted in approximately one third of the cases in the success endpoint of PPD ≤ 5mm. Sub‐analysis showed that the outcome appeared to be dependent on tooth type, furcation involvement, severity of periodontal disease at intake and smoking status.

Efficacy of Acacia arabica gum as an adjunct to scaling and root planing in the treatment of chronic periodontitis: A randomized controlled clinical trial

Aim

The aim of the present study was to explore the adjunctive use of Acacia arabica gel in the treatment of chronic periodontitis.

Methods

Single centre, randomised, triple blind, controlled trial on mild to moderate chronic periodontitis patients; Group I (SRP + Acacia arabica, n = 40) and Group II (SRP + placebo, n = 40); were analysed for clinical improvements in periodontal pocket depth (PPD) and clinical attachment levels (CAL) at baseline, 15 and 90 days on application of gels. Gingival index and plaque index were assessed as secondary parameters.

Results

Statistically significant PPD reduction (p < .05) and CAL gain (p < .05) was observed with use of Acacia arabica gel. The reduction in sites with moderate PPD was observed more among Group I than Group II and the difference was statistically significant (p = .001). Secondary outcome variables; Plaque Index and Gingival Index showed better resolution with Acacia arabica gel.

Conclusion

Acacia arabica leads to better clinical outcomes in patients with mild to moderate chronic periodontitis with effective antiplaque and anti-gingivitis action. It may be recommended adjunct to SRP for maintenance in patients with mild to moderate chronic periodontitis.

Immunohistochemical characterization of periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs

BACKGROUND AND OBJECTIVE

The aim of the present study was to immunohistochemically characterize periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs.

STUDY DESIGN/MATERIALS AND METHODS

Five beagle dogs suffering from naturally occurring chronic periodontitis were randomly allocated in a split-mouth design to nonsurgical periodontal treatment using either (a) an Er:YAG laser at 10.2, 12.8, 15.4, 18, and 20.4 J/cm2 (ERL1-5), or (b) an ultrasonic device (VUS) serving as control. The animals were sacrificed after 3 months. Histomorphometrical (e.g. inflammatory cell infiltrate, surface changes, cementum formation), and immunohistochemical parameters (collagen type I, CD68, matrix metalloproteinase (MMP)-8) were assessed.

RESULTS

Inflammatory cell infiltrates of different extent were commonly observed in all treatment groups. However, histomorphometrical analysis revealed new cementum formation with inserting collagen type I fibers along the instrumented root surfaces in most specimens of both ERL (ERL2: 31+/-81 to ERL5: 595+/-575 microm) and VUS (50+/- 215 microm) groups. This was associated with pronounced CD68 and weak MMP-8 antigen reactivity.

CONCLUSION

Within the limits of the present study, it was concluded that both treatment procedures (i) were effective in controlling inflammatory cell infiltrates, and (ii) may support the formation of a new connective tissue attachment.

Sonic and ultrasonic scalers in periodontal treatment: a review

Periodontal therapy aims at arresting periodontal infection and maintaining a healthy periodontium. The periodic mechanical removal of subgingival microbial biofilms is essential for controlling inflammatory periodontal disease. Mechanical periodontal therapy consists of scaling, root planing and gingival curettage. The sonic and ultrasonic scalers are valuable tools in the prevention of periodontal disease. The vibration of scaler tips is the main effect to remove the deposits from the dental surface, such as bacterial plaque, calculus and endotoxin. However, constant flushing activity of the lavage used to cool the tips and cavitational activity result in disruption of the weak and unattached subgingival plaque. The aim of the study was to review the safety, efficacy, role and deleterious side-effects of sonic and ultrasonic scalers in mechanical periodontal therapy.

Influence of fluorescence-controlled Er:YAG laser radiation, the Vectortm system and hand instruments on periodontally diseased root surfaces in vivo

OBJECTIVES

The aim of the present study was to evaluate the effects of fluorescence-controlled Er:YAG laser radiation, an ultrasonic device or hand instruments on periodontally diseased root surfaces in vivo.

MATERIAL AND METHODS

Seventy-two single-rooted teeth (n=12 patients) were randomly treated in vivo by a single course of subgingival instrumentation using (1-3) an Er:YAG laser (ERL1: 100 mJ; ERL2: 120 mJ; ERL3: 140 mJ; 10 Hz), or (4) the Vector ultrasonic system (VUS) or (5) hand instruments (SRP). Untreated teeth served as control (UC). Areas of residual subgingival calculus (RSC) and depth of root surface alterations were assessed histo-/morphometrically.

RESULTS

Highest values of RSC areas (%) were observed in the SRP group (12.5+/-6.9). ERL(1-3) (7.8+/-5.8, 8.6+/-4.5, 6.2+/-3.9, respectively) revealed significantly lower RSC areas than SRP. VUS (2.4+/-1.8) exhibited significantly lower RSC areas than SRP and ERL(1, 2). Specimens treated with SRP revealed conspicuous root surface damage, while specimens treated with ERL(1-3) and VUS exhibited a homogeneous and smooth appearance.

CONCLUSION

Within the limits of the present study, it may be concluded that ERL and VUS enabled (i) a more effective removal of subgingival calculus and (ii) a predictable root surface preservation in comparison with SRP.

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

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

A sheep cadaver model for demonstration and training periodontal surgical methods

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

The Effectiveness of InGaAsP Diode Laser Radiation to Detect Subgingival Calculus as Compared to an Explorer

BACKGROUND

The aim of the present study was to compare the ability of the diode laser to detect residual calculus with that of an explorer.

METHODS

The root surface of 40 extracted human teeth, each partially covered with subgingival calculus, was instrumented with curets under simulated clinical conditions in a manikin. The samples were randomly assigned to two study groups. In group A, the root surface was treated with an explorer until it appeared free of mineralized deposits upon examination. The samples in group B were instrumented until the relative intensity of fluorescence as induced with diode laser radiation was below a threshold value of 5. The root surface of each sample was then examined for residual calculus using standardized digital images. The statistical analysis was performed with a non-paired t test at a level of significance of 5% (P < 0.05).

RESULTS

The root surface of single-rooted teeth showed residual calculus on 0.19 +/- 0.37 x 10(7) microm2 in the laser group and on 0.11 +/- 0.26 x 10(7) microm2 in the explorer group (P = 0.19). For multirooted teeth, the mean calculus-covered area was 0.50 +/- 0.48 x 10(7) microm2 for the teeth evaluated with an explorer and 0.27 +/- 0.43 x 10(7) microm2 for the diode laser group (P = 0.02).

CONCLUSION

The present findings indicate that the detection of subgingival calculus is significantly improved using 655 nm diode laser radiation compared to an explorer for molars but not for single-rooted teeth.

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.

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.

A comparison of the success of root resected molars and molar position implants in function in a private practice: results of up to 15-plus years

BACKGROUND

When faced with a furcated molar, today's clinician must decide between a number of treatment options, including root resection, tooth removal, and implant placement. This paper assesses the results in one private clinical practice of root resection and subsequent restoration or molar implant placement and subsequent restoration. Clinical considerations in treatment selection are discussed.

METHODS

A retrospective analysis of treated patients was carried out by examining active and inactive patient charts. When patients had discontinued therapy, every effort was made to determine the reason for leaving the private practice, so as to assess the impact of previously undocumented treatment failure on the statistics in question.

RESULTS

A total 701 root resected molars and 1,472 molar implants were evaluated after > or = 15 and 13 years in function, respectively. Resection of the distal root of a mandibular molar demonstrated the lowest success rate (75%). All other success rates for various root resected molars in function ranged from 95.2% to 100%. Lone standing implants in second molar positions demonstrated the lowest success rate (85%). All other implant use in molar positions demonstrated a success rate ranging from 97.0% to 98.6%. Root resected molars and molar implants demonstrated the highest degree of failure when they were lone standing terminal abutments. Seven out of 23 (30.4%) root resected molar failures, and 17 of 45 (37.8%) of the molar implant failures were associated with untreated parafunction. Cumulative success rates were 96.8% for root resected molars and 97.0% for molar implants. Success and failure are discussed by tooth and/or implant position, and resected root, where applicable. Possible ramifications of these findings upon treatment planning are also reviewed.

CONCLUSIONS

Both molar root resection and appropriate restoration and molar implant placement and restoration demonstrated a high degree of success in function. However, this success rate is markedly affected when either the root resected molar or molar implant is a lone standing terminal abutment. Care must be taken to choose the appropriate treatment modality for a given patient scenario.

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.

Periodontal treatment decisions for molars: an analysis of influencing factors and long-term outcome

BACKGROUND

The purpose of this retrospective study was 1) to analyze factors influencing the treatment decision for periodontitis-affected molars and 2) to evaluate the long-term outcome of the decision. The treatment alternatives included in the analysis were maintenance of the tooth with only non-surgically/surgically performed scaling/root planing with or without furcation plasty, root separation/resection, and tooth extraction.

METHODS

Data collected from a total of 1,313 first and second molars in 222 patients (mean age 45 years; range 14 to 73 years), referred for periodontal treatment, were analyzed with respect to treatment decisions for furcation-involved teeth. The patients had been examined with respect to oral hygiene status, gingival conditions, probing depth, furcation involvement, and radiographic bone height before and after active periodontal treatment. Frequencies, mean values and standard deviations were calculated for the various variables assessed. Multiple regression models were formulated in order to analyze the influence of various variables on treatment decisions. One-hundred and sixty (72%) of the patients agreed to participate in a follow-up examination to determine the clinical and radiographic status of the molars 8 to 12 years after the active phase of treatment for evaluation of the long-term outcome of the treatment decision.

RESULTS

Twenty-eight percent of the molars were extracted and 4% were root separated/resected. Factors found to significantly influence the decision of tooth extraction were tooth mobility, tooth position, lack of occlusal antagonism, degree of furcation involvement, and remaining bone support. Of the factors analyzed with respect to root separation/resection, molar position and degree of furcation involvement showed the strongest influence on the treatment decision. The 8- to 12-year follow-up examination revealed that 96% of the molars subjected to non-resective therapy were still in function. The corresponding figure for root separated/resected molars was 89%. Loss of radiographic bone support during the 10-year follow-up period was 0.1 to 0.6 mm for the various molars with the highest value for maxillary second molars.

CONCLUSIONS

A conservative approach to the treatment of molars with even deep furcation invasions may show a high long-term success rate, provided maintenance care is offered.

Treatment of molar furcation involvement using root separation and a crown and sleeve-coping telescopic denture. A longitudinal study

Because of the inconsistent results of periodontal and prosthetic therapy, periodontists may choose to treat maxillary molar furcation involvements (FI) with poor root morphology utilizing a root resection technique (RRT). In addition, poor root morphology of the remaining root following RRT is usually considered a high risk factor for long-term periodontal and prosthetic success. The purpose of this retrospective study was to investigate the differences in the clinical periodontal parameters between molar abutments with and without molar root separation and/or resection (RSR) before and after periodontal and prosthetic therapy, using a crown and sleeve-coping telescopic denture (CSCTD). A total of 85 molars (47 maxillary and 38 mandibular) were treated in 25 subjects. There were 33 abutments without root separation/resection and 52 abutments with RSR. Forty-three CSCTD were placed, 23 in the maxillary arch and 20 in the mandibular arch. The mean observation period was 6.7+/-1.9 years (range, 5 to 13 years). The plaque index, gingival index, probing depth, clinical attachment level, and alveolar bone change were recorded. The differences in these parameters before and after periodontal and prosthetic therapy between the advanced furcation-involved molars with and without RSR were evaluated. The results revealed a remarkable improvement in the periodontal parameters in advanced Class II and Class III FI in molars with RSR as compared to those without RSR. It was, therefore, concluded that molar abutments with RSR in conjunction with a specifically designed telescopic device provide a modified approach for treating molars with advanced Class II and III FI.

Instrumentation of furcation with modified sonic scaler inserts: a study on manikins (II)

We developed a sonic scaler tip with an ellipsoid diamond-coated bud and contra-angulated shafts to overcome problems resulting from furcation anatomy. In this study, extracted molars were instrumented in a dummy model without any replicated soft tissues using 3 different instrumentation methods (i) curettes, (ii) diamond-coated sonic scaler tips with normal handle and (iii) diamond-coated sonic scaler tips in 2 handles with varying power levels. 15 extracted upper and lower molars were instrumented using each of the 3 instrumentation types. Following debridement, loss of substance and % of furcation area instrumented were assessed. In both upper and lower molars, significantly more surface area was instrumented in one instrumentation run with diamond-coated tips than with curettes. Substance loss was greater with diamond-coated tips than with hand instruments. In conclusion, an effective debridement of the furcation roof seems only possible with odontoplasty. Clinical evaluation of this approach to root debridement is needed.

Instrumentation of furcation with modified sonic scaler inserts: study on manikins, part I

The purpose of this study was to determine the suitability of different scaling instruments for the debridement of furcations. 12 upper and 12 lower replicated molars with through-and-through furcations were instrumented 3x with 5 different types of instruments: (i) hand instruments; (ii) hand instruments in conjunction with diamond burrs; (iii) a conventional ultrasonic scaler insert; (iv) a conventional sonic scaler insert; (v) a set of 2 modified diamond coated sonic scaler inserts with different angulated shafts. The plastic replicas were fixed in a manikin head without replicated soft tissues. Following debridement, weight loss and % of instrumented furcation area were assessed. In the case of lower molars, it made little difference whether they were treated with hand instruments, hand instruments combined with diamond burrs, or diamond-coated sonic scaler inserts. On upper molars, however, significantly more area was instrumented with the diamond-coated inserts than with the other instruments. Substance removal was greater with diamond-coated inserts than with the other devices. In conclusion, an effective debridement of the furcation seems possible only with an odontoplasty, in which a furcation is fitted to the instrument by means of intensive instrumentation, thus leading to substance loss. To improve results with these instruments, further research is necessary.

Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. II. Furcation area

The purpose of this study was to demonstrate the extent of deposits removed from within the furcation area of mandibular first molars following the use of curets with a modified blade and slim ultrasonic inserts in an in vitro model simulating a closed root debridement approach to furcation treatment. The furcation areas of 100 artificial mandibular first molars were uniformly coated with black model paint. The molars were fixed into a custom acrylic model, maintained in a firm position with modified occlusal splints, and the roots covered with a heavy rubber dam. The model was set in a mannequin and mounted on a dental chair recreating a clinical situation. Fifty molars (25 right, 25 left) were instrumented with the experimental curets and an equivalent number of molars with the ultrasonic inserts. An experienced dental hygienist completed all the instrumentation, spending 4 minutes on each molar. The molars were sectioned buccolingually from the crown apically to separate the roots, and areas in the internal surface of mesial and distal roots were analyzed to determine the percentage of deposits remaining using a computerized imaging routine system. A 2-factor analysis of variance was conducted to test for differences between both types of instruments. The curets produced furcation root surfaces with significantly less percentage of residual deposits than the ultrasonic inserts (P < 0.01). This study indicates the potential value of small bladed curets in debriding involved furcations during initial therapy and supportive periodontal therapy. The current findings should be corroborated in a clinical study.

Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. I. Root trunk and furcation entrance

The purpose of this study was to compare curets with a small blade to slim ultrasonic inserts on their efficacy in removing artificial deposits from the root trunk and furcation entrance areas of mandibular molars using an in vitro model simulating a clinically closed root debridement approach. The study was conducted on 100 artificial mandibular first molars (50 right side and 50 left side) with anatomical roots. Root trunks, furcation entrances, and furcation areas of each molar were colored by a coat of black model paint. The teeth were fixed in a custom acrylic model and maintained in a firm position by modified acrylic occlusal splints. The root areas were covered with a heavy rubber dam imitating gingival tissue. The model was attached to a mannequin and mounted on a dental chair. Fifty molars (25 right, 25 left) were instrumented with the experimental curets and an equivalent number of molars with the ultrasonic inserts. The instrumentation was carried out by one experienced operator, spending 4 minutes on each molar. The instrumented areas were individually analyzed to determine the percentage of deposits remaining, using a computerized imaging routine system. One-way analysis of variance was conducted to test for differences between both types of instruments. Results revealed that the curets were significantly more efficient (P < 0.01) than the ultrasonic inserts in removing paint from both root trunks and furcation entrances. These findings should be corroborated in a clinical study to determine the potential value of the instruments tested during initial therapy or supportive care of involved mandibular furcations.

Dental calculus: recent insights into occurrence, formation, prevention, removal and oral health effects of supragingival and subgingival deposits

Dental calculus, both supra- and subgingival occurs in the majority of adults worldwide. Dental calculus is calcified dental plaque, composed primarily of calcium phosphate mineral salts deposited between and within remnants of formerly viable microorganisms. A viable dental plaque covers mineralized calculus deposits. Levels of calculus and location of formation are population specific and are affected by oral hygiene habits, access to professional care, diet, age, ethnic origin, time since last dental cleaning, systemic disease and the use of prescription medications. In populations that practice regular oral hygiene and with access to regular professional care, supragingival dental calculus formation is restricted to tooth surfaces adjacent to the salivary ducts. Levels of supragingival calculus in these populations is minor and the calculus has little if any impact on oral-health. Subgingival calculus formation in these populations occurs coincident with periodontal disease (although the calculus itself appears to have little impact on attachment loss), the latter being correlated with dental plaque. In populations that do not practice regular hygiene and that do not have access to professional care, supragingival calculus occurs throughout the dentition and the extent of calculus formation can be extreme. In these populations, supragingival calculus is associated with the promotion of gingival recession. Subgingival calculus, in "low hygiene" populations, is extensive and is directly correlated with enhanced periodontal attachment loss. Despite extensive research, a complete understanding of the etiologic significance of subgingival calculus to periodontal disease remains elusive, due to inability to clearly differentiate effects of calculus versus "plaque on calculus". As a result, we are not entirely sure whether subgingival calculus is the cause or result of periodontal inflammation. Research suggests that subgingival calculus, at a minimum, may expand the radius of plaque induced periodontal injury. Removal of subgingival plaque and calculus remains the cornerstone of periodontal therapy. Calculus formation is the result of petrification of dental plaque biofilm, with mineral ions provided by bathing saliva or crevicular fluids. Supragingival calculus formation can be controlled by chemical mineralization inhibitors, applied in toothpastes or mouthrinses. These agents act to delay plaque calcification, keeping deposits in an amorphous non-hardened state to facilitate removal with regular hygiene. Clinical efficacy for these agents is typically assessed as the reduction in tartar area coverage on the teeth between dental cleaning. Research shows that topically applied mineralization inhibitors can also influence adhesion and hardness of calculus deposits on the tooth surface, facilitating removal. Future research in calculus may include the development of improved supragingival tartar control formulations, the development of treatments for the prevention of subgingival calculus formation, the development of improved methods for root detoxification and debridement and the development and application of sensitive diagnostic methods to assess subgingival debridement efficacy.

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.

Proof of efficacy of different modified sonic scaler inserts used for debridement in furcations--a dummy head trial

The purpose of this study was to determine the suitability of different scaling instruments for surgical removal of hard and soft bacterial deposits and for the removal of soft accretions only for maintenance treatment within furcations. 12 upper and 12 lower plastic replicated molars, with through-and-through furcations, were instrumented 3 x with 4 different types of instruments: (1) hand instruments; (2) a conventional sonic scaler insert; (3) a set of 3 modified sonic scaler inserts with budded tips and different angulated shafts; (4) a set of 3 sonic scaler inserts with a plastic-coating and different angulated shafts. The plastic replicas were fixed in a dummy head without any replicated soft tissues. In the furcation area, an easily removable surface coating material was applied to the teeth to represent the "plaque" and a second, more stubborn lacquer layer representing "calculus/cementum". Following instrumentation, the following parameters were recorded to assess efficacy; time required for instrumentation, loss of weight, depth of substance removal at the furcation entrance, % of furcation area instrumented, whereby removal of these 2 layers was judged separately. Only minor differences were observed between hand instruments, conventional and budded sonic scaler inserts as to loss of weight, depth of substance loss and area instrumented. The plastic-coated sonic scaler inserts were just as effective in surface layer removal representing "plaque" as the 3 other instruments, but resulted in less loss of weight and less depth of substance removal. In conclusion, the more aggressive hand instruments, the conventional and budded sonic scaler insert, are preferably used for the surgical phase to increased ease of entry into the furcation dome. An effective debridement of the furcation roof seems only possible with an odontoplastic, for which a furcation is fitted to the instrument by means of an intensive instrumentation, thus leading to weight loss and pronounced substance removal. The plastic-coated sonic scaler inserts seems to be a reasonable choice for maintenance treatment within furcation, since this treatment phase is usually restricted to removal of soft bacterial deposits.