A comparison of the effectiveness of hand scaling and ultrasonic debridement in furcations as evaluated by differential dark-field microscopy

Ultrasound in dentistry. Part 2--Periodontology and endodontics

Ultrasound in the kHz frequency range is used widely in clinical dentistry. The most common uses are in the fields of periodontology and endodontics. The ultrasonic scaler works by the vibratory chipping action of the oscillating tip and is assisted by the presence of cavitational activity in the associated cooling water. When assessing clinical studies it is often difficult to interpret results from different workers due to the lack of standardization of the ultrasonic scaler. Operators should be aware of the oscillatory pattern of different instruments. Endosonics utilizes an ultrasonically oscillating endodontic file to clean and shape the root canal prior to obturation. The cleaning ability of such files is assisted by the occurrence of acoustic microstreaming forces. The endosonic file is prone to constraint when it contacts the canal wall which alters its oscillatory pattern. Clinical techniques should be modified to reduce this problem.

New views on periodontal microbiota in special patient categories

The microorganisms in periodontitis of special patient categories have been only partially elucidated. The periodontitis microbiota of HIV-infected individuals, cancer patients on myelosuppressive therapy, and persons with other medical disorders includes common suspected periodontal pathogens as well as enteric rods, pseudomonads, staphylococci and yeasts. Failing implants also may be associated with classical periodontal pathogens as well as primarily nonoral potential pathogens. Refractory periodontitis in systemically healthy adults can show a great variety of oral and nonoral organisms. The frequent occurrence of unusual periodontal organisms in special patient categories may be due to a weakened host response and/or usage of various chemotherapeutic regimens. The unusual organisms may contribute to progressive periodontitis and in leukemia patients may even give rise to life-threatening systemic manifestations. The primary therapeutic goal in special periodontitis patients is control of pathogens and amid the wide range of pathogenic microfloras, an effective treatment strategy should include a comprehensive microbiological analysis, especially if systemic antimicrobial therapy is contemplated.

Closed versus open debridement of facial grade II molar furcations

Clinical responses of facial grade II molar furcations to closed (C) versus open (O) debridement were evaluated. 25 teeth were treated at baseline (BL) with scaling/root planning (S/RP) and evaluated at 4 months. 12 of the teeth were then treated with open flap debridement and the remaining teeth were treated with further S/RP. Clinical parameters of plaque, gingival inflammation, bleeding on probing, gingival fluid flow, pocket depth and probing attachment level were taken at BL, 4, 7, 10, 13 and 16 months. Pairwise differences were determined between visits and a t-test was applied to differences for C and O. For both treatment groups, the greatest changes in clinical parameters occurred from BL - 4 months. Plaque and gingival inflammation showed a gradual reduction from BL throughout the study for both groups. A reduction in pocket depth from BL - 16 months was noted in both groups (mid-furcal, C = 1.5 mm, O = 1.2 mm; root prominence, C = 1.02 mm, O = 0.84 mm)! There was a gain in probing attachment level in the midfurcal area for the C group (0.6 mm) while the O group lost (-0.46 mm). There were no statistically significant differences found for any clinical parameter between closed and open debridement. The presence of plaque and bleeding at a furcal site had not significant effect on treatment response.

Periodontal implications of furcation entrance dimensions in Chinese first permanent molars

Narrow dimensions of the entrance to furcations of multi-rooted teeth can complicate the periodontal management of furcation involvements. The objectives of this study were to measure the furcation entrance dimensions of first permanent molars from Hong Kong Chinese, and to compare these dimensions with those of the blade widths of periodontal instruments generally advocated for root surface instrumentation. A total of 363 first permanent molars, of which 185 were maxillary, were examined under 1.5 x magnification. Furcation entrance dimensions were measured using calibrated test gauges ranging from 0.3 mm to 1.5 mm. Furcation entrance dimensions equal to or less than 0.75 mm (the blade width of a new Gracey curet being 0.76 mm) in maxillary first molars were found in 79% of buccal entrances, 39% of mesial entrances, and 43% of distal entrances. In mandibular first molars, entrance dimensions equal to or less than 0.75 mm were encountered in 36% and 47% of buccal and lingual furcation entrances respectively. One-half of all furcation entrance dimensions of these first molars were less than the blade width of new Gracey curets. This high prevalence of narrow furcation entrances should be considered in the periodontal management of furcation involvement of first molars in Chinese.

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.

Current concepts of periodontal maintenance

Changing concepts and a more complete understanding of the aetiology of chronic marginal periodontitis allow a more rational approach to the treatment of patients with periodontal diseases. A sequence of treatment steps of increasing complexity is presented for the prevention of recurrence of chronic marginal periodontitis during the maintenance phase of treatment.

The effect of 1% metronidazole gel in routine maintenance of persistent furcation involvement in human beings

The aim of this study was to test adjunctive insertion of 1% metronidazole gel into furcation areas during periodontal maintenance. Ten patients were selected with paired, contralateral, Class II or III furcation involvements that also bled on constant force probing. Bleeding on probing (BOP) and gingival crevicular fluid (GCF) were measured as experimental variables. Plaque was assessed by dark-field microscopy (DFM). Following routine subgingival maintenance of these sites, a syringe was used to insert metronidazole or placebo gels into the furcations. Sites were re-examined 1 and 3 months after baseline. There was little change in either BOP or GCF. Marked longitudinal changes were found by DFM for both experimental and control sites. Experimental sites were not significantly different when compared with controls at the 5% level of probability.

Clinical effects of root debridement in molar and non-molar teeth. A 2-year follow-up

12 patients were studied longitudinally to monitor the effects of basic periodontal therapy in molar and non-molar teeth. Periodontal sites were grouped into molar furcation sites, molar flat-surface sites and non-molar sites. Clinical measurements were taken at baseline and directly followed by full mouth root debridement. Subsequently, measurements were taken every 3rd month until 24 months. At each of these appointments, the patients were monitored for their oral hygiene performance and given supragingival prophylaxis. The mean results indicated that initially moderately deep and deep molar furcation sites responded less favorably to therapy compared to non-molar sites and molar flat-surface sites of similar probing depth. Initial improvements in probing measurements for moderately deep and deep molar furcation sites were limited and also tended to revert during the observation interval. Identification of individual sites with probing attachment loss disclosed that 25% of molar furcation sites lost probing attachment as compared to 7% for non-molar sites and 10% for molar flat-surface sites. These results corroborate previous findings and call for additional or alternative treatment regimens for periodontal furcation pockets.

Evaluation of furcation region response to periodontal therapy

Five hundred fifty-eight molars were treated with one of four types of periodontal therapy: coronal scaling (CS); root planing (RP); modified Widman surgery (MW); or flap with osseous resectional surgery (FO). This report presents the probing depth and probing attachment changes in the furcation region following therapy and two years of maintenance follow-up. All types of therapy were effective in reducing probing depths. FO was the most effective in reducing probing depth followed by MW, RP, and CS. Reduction in probing depth was primarily due to gingival recession. FO resulted in a loss of probing attachment in both a vertical and horizontal direction following therapy. Following two years of maintenance care, sites treated with FO continued to exhibit a mean net loss of vertical probing attachment. A mean net loss of horizontal probing attachment was present after two years of maintenance care, regardless of the treatment modality employed. Many more sites were initially removed during osseous resectional surgery to achieve treatment criteria than were initially removed from the other groups. FO treated teeth demonstrated a lesser percentage of furcation sites demonstrating clinically significant breakdown during the two years of maintenance care.

Clinical and microbiological effects of root debridement in periodontal furcation pockets

The aim of the present study was to investigate longitudinally over 52 weeks the clinical and microbiological effects of plaque control and root debridement at molar furcation sites. The results were compared with changes at non-molar sites. 24 non-molar sites and 31 grade II molar furcation sites with probing depth greater than or equal to 5.0 mm were monitored in 11 patients. Clinical measurements consisted of plaque scores, probing depths, and changes in probing attachment level. Microbiological monitoring was carried out with phase-contrast microscopy and anaerobic culturing. The debridement resulted in improvement in probing measurements and microbiological counts for both groups of sites. A slightly less favorable clinical response was noted for molar furcation sites. Higher post-operative microbiological counts were found throughout the 52-week observation period for molar furcation sites. Sites with probing attachment loss showed higher microbial counts and higher proportions of spirochetes, black pigmented colony forming units (CFU), and Bacteroides gingivalis CFU than sites with probing attachment gain. Individual site analysis, however, demonstrated marked variations of the microbiological counts at the different postoperative time points. In the few available sites undergoing probing attachment loss, no apparent association between target micro-organisms and periodontal deterioration was observed.

Treatment of periodontal furcation defects. (I). Review of the literature and description of a regenerative surgical technique

This report provides an abbreviated review of the literature on treatment and prognosis of periodontal furcation lesions. In addition, it describes a surgical technique designed to accomplish bone regeneration in class II furcation defects, together with the rationale for the development of this procedure. Results of treatment of 30 defects with this technique are presented in a subsequent report.

Treatment of periodontal furcation defects. (II). Bone regeneration in mandibular class II defects

A total of 30 mandibular, buccal class II furcation defects were treated in 22 subjects using a regenerative surgical therapy that included citric acid root conditioning and coronally positioned flaps secured by crown-attached sutures. In addition, grafts of freeze-dried, decalcified allogenic bone were placed in 16 of the 30 defects. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. These measurements demonstrated notable improvement 12 months following therapy. On the average, 67% of the defect volume became filled with bone. 43% of treated defects were completely closed by bone fill. No difference was observed between defects treated with and without bone grafts.