Effectiveness of subgingival scaling and root planing: single versus multiple episodes of instrumentation.

This study evaluates the effectiveness of subgingival scaling and root planing comparing the effect of a single instrumentation to the effect of three instrumentations. A total of 35 teeth in 15 patients were selected; 15 were scaled once (Group A), 15 were scaled three times (Group B), and 5 were used as controls (Group C), representing teeth that were not instrumented. The Group A and B teeth were chosen in the same patient based on random selection. All the teeth were scored by the calculus index of the periodontal disease index. Six surface locations were probed to determine probing depth. The level of the gingival margin was marked on the teeth to locate supra- and subgingival calculus after extraction. The Group A and B teeth received the initial episode of scaling and root planing for not more than 10 minutes, then only the Group B teeth received two additional instrumentations of not more than 5 minutes each. The additional instrumentations were performed 24 hours after the initial scaling. The scaled and control teeth were extracted immediately after the third instrumentation period. The teeth were washed with water and stained with methylene blue. They were viewed under a stereomicroscope which had a tenth grid on its eyepiece. Assessments were made involving the total counts and percents of the surfaces covered with calculus on the scaled and unscaled teeth. The results demonstrated no significant difference in the effectiveness of calculus removal between single and multiple episodes of scaling and root planing. Similar results were found for the total amount of calculus removed, the calculus removed from individual surfaces, and the calculus removed from various probing depth levels.

Concentrations of fibronectin in the sera and crevicular fluid in various stages of periodontal disease.

While fibronectin (FN) has previously been demonstrated to be present in gingival crevicular fluid (GCF), its quality and quantity has not been reported. Since this information is relevant for ongoing studies on the use of FN for gingival reattachment, we performed these measurements and compared plasma levels in healthy subjects, patients with gingivitis and periodontitis, and in patients undergoing maintenance therapy. Plasma and GCF samples were obtained from 4 sites in each subject using a Periotron to permit quantification of samples. FN concentrations were determined in a microELISA using hyperimmune anti-FN antibody. Purified FN served as a reference for quantification. The functional activity of each sample was assessed by examining the natural affinity of FN for gelatin. Subjects with gingivitis and those in maintenance had significantly depressed levels of plasma fibronectin. While little fibronectin could be detected in the GCF of healthy sites regardless of patient category, examination of the most diseased sites in each group revealed that the concentration of FN in the GCF was highest in health and reduced when there was gingival inflammation. In no case was GCF FN found to be biologically active.

The effect of a Microsil-containing dentifrice in the prevention and treatment of gingivitis.

The purpose of this study was to determine if a Microsil-containing dentifrice (Minnetonka, Inc., Minnetonka, Minnesota) could enhance the therapeutic effectiveness of toothbrushing relative to plaque control as well as the prevention and treatment of gingivitis. Volunteer 12 through 14 year-old elementary school students were divided into two experimental groups and one control group. Following baseline examination, scorings were made after consecutive forty-five day experimental periods which were separated by an interim prophylaxis. One of the Microsil-containing dentifrices was found to significantly reduce existing plaque and gingivitis levels at specific locations. The same experimental dentifrice was also shown in specific areas to permit better maintenance of the reduced gingivitis levels achieved following prophylaxis. It was concluded that the results obtained with a Microsil-containing dentifrice were encouraging in that any additional effect in reducing plaque and controlling gingivitis would be especially beneficial for young individuals in whom gingivitis is such a common finding.

Histologic evaluation of periodontal implants in a biologically "closed" model.

To study the biologic response, three commercial calcium phosphate implant materials (Calcitite, Periograf, Synthograft) were implanted in cuspid root "windows" in four beagle dogs. No implant material was placed in the fourth cuspid window which served as a control. Following mucoperiosteal flap elevation, windows were chiseled in bone to the root surface which allowed implant particles to contact bone, fibrous connective tissue, cementum and dentin without exposure to the oral environment. Animals were sacrificed after 1, 3, 5 and 6 months. Histologically, all implant materials were well tolerated. At 1 month, implant particles were surrounded by fibrous tissue. Fibrous tissues filled the control defect. At 3 months, implant sites exhibited partial bony repair with connective tissue surrounding implant particles. A ring of osteoid surrounded Synthograft particles. Control defect repair was complete. At 5 and 6 months, implant sites exhibited advanced, though incomplete, bony repair. New bone encompassed the Synthograft particles. It was concluded: Control sites healed most rapidly. Calcitite and Periograft were well tolerated space occupiers. Synthograft was a nidus for bone deposition.

The effect of different plaque control modalities on the keratinizing potential of the sulcular epithelium in monkeys.

The purpose of this study was to determine if various plaque control regimes would be effective in permitting the gingival sulcular epithelium to keratinize. Three adult Rhesus monkeys had their teeth scaled and were placed on specific plaque control regimes including various combinations of prophylaxes, topical chlorhexidine and systemic tetracycline. Over the 2-month experimental period, weekly Plaque and Gingival Indices were determined. Subgingival plaque samples were obtained during the first 2 treatment weeks and at the end of the 1st month. Block sections of individual teeth from the different experimental regimes were serially sectioned to be evaluated histologically for inflammation and keratinization. Plaque and Gingival Indices were significantly reduced by the end of the 8th week compared to the pretreatment levels for all experimental regimes, except that the regime consisting only of three prophylaxes per week failed to reduce the Gingival Index significantly. Rubber cup prophylaxes were less effective in reducing plaque and inflammation than when the prophylaxes were combined with topical chlorhexidine application or systemic tetracycline administration. However, all experimental regimes were capable of reducing the subgingival bacterial flora to a level permitting sufficient reduction in gingival inflammation so that sulcular keratinization would occur. Some degree of sulcular keratinization was observed for every tooth of all experimental regimes. All regimes caused a significant decrease in the Inflammatory Indices relative to the control values. A negative correlation was found between the Crestal Inflammatory Index and the Keratin Width and Keratin Length, while a positive correlation was apparent between the Keratin Width and Keratin Length.