No abstract available.

Dental plaque, a biofilm consisting of more than 500 different bacterial species, is an etiological agent of human periodontal disease. It is therefore important to characterize interactions among periodontopathic microorganisms in order to understand the microbial pathogenesis of periodontal disease. Previous data have suggested a synergistic effect of tow major periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia in the periodontal lesion. In the present study, to better understand interaction between P. gingivalis and T. forsythia, the coaggregation activity between these bacteria was characterized. The coaggregation activity was observed by a direct visual assay by mixing equal amount (1 x 10(9)) of T. forsythia and P. gingivalis cells. It was found that the first aggregates began to appear after 5-10 min, and that the large aggregates completely settled within 1 h. Electron and epifluorescence microscopic studies confirmed cell-cell contact between two bacteria. The heat treatment of P. gingivalis completely blocked the activity, suggesting an involvement of a heat-labile component of P. gingivalis in the interaction. On the other hand, heat treatment of T. forsythia significantly increased the coaggregation activity; the aggregates began to appear immediately. The coaggregation activity was inhibited by addition of protease, however carbohydrates did not inhibit the activity, suggesting that coaggregation is a protein-protein interaction. The results of this study suggest that coaggregation between P. gingivalis and T. forsythia is a result of cell-cell physical contact, and that coaggregation is mediated by a heat-labile component of P. gingivalis and T. forsythia component that can be activated on heat treatment.
Bacteria ; Biofilms ; Carbohydrates ; Dental Plaque ; Forsythia* ; Hand ; Hot Temperature ; Humans ; Periodontal Diseases ; Porphyromonas gingivalis* ; Porphyromonas*

The purpose of this study was to evaluate the influence of accessibility to dental cervices of maxillary molars upon plaque control level of these areas. Fifthy-seven dental students with healthy gingiae participated in this study. Maxillary dental casts were fabricated for each participants. Using the casts, cervical accessibility was measured at the mid-palatal point of maxillary first and second molars. Cervical accessibility was defined as the perpendicular distance from the entrance of gingival sulcus to the imaginary line between the most protruded points of palatal gingiva and tooth surface, and classified into degree I(< or =0.5mm), II(>0.5mm, < or =1.0mm), III(>1.0mm, < or =1.5mm), and IV(>1.5mm). Plaque score was recorded as the distance from crest of gingival margin to the most coronal extent of plaque. Measurements of plaque score were repeated 3 times at 1-week intervals. After the baseline measurements, the participants began to use unitufted brushes on randomly assigned right or left side. Two weeks later, a session of plaque score records identical to the baseline measurements was started. The maxillary second molars showed higher cervical accessibility than the first molars(p<0.01), but the plaque scores of maxillary second molars were also higher than those of first molars(p<0.01). For the maxillary first molars, correlation between accessibility and plaque score was statistically significant, but such correlation was not found for the second molars. Use of unitufted brushes decreased the plaque score(p<0.01). Correlation between accessibility and the degree of plaque score improvement was not found. These findings suggest that cervical accessibility may influence the amount of plaque, and use of adjunctive oral hygiene devices may be helpful in maintaining optimal oral hygiene level at the areas of low cervical accessibility.
Gingiva ; Humans ; Molar* ; Oral Hygiene ; Students, Dental ; Tooth

No abstract available.
Chlorhexidine* ; Guided Tissue Regeneration*

Perforation of maxillary sinus is a common complication of implant placement in posterior maxilla. The purpose of this study was to evaluate the prognosis of sinus perforated implants placed in partially edentulous maxillae. Eighteen sinus perforated implants in 15 patients were examined for cumulative survival rate, radiographic preoperative bone level, and radiographic marginal bone level change. Twenty-two non-perforated implants in the same patients served as control. The results were as follows; 1. There was no statistically significant difference in cumulative survival rate between sinus perforated implants and non-perforated implants (P>0.05). 2. There was no statistically significant difference in the marginal bone level between sinus perforated implants and non-perforated implants (P>0.05). 3. There was no statistically significant difference in cumulative survival rate according to the preoperative bone level (P>0.05). These results suggests that perforation of maxillary sinus may not affect implant success in posterior maxillae.
Humans ; Maxilla ; Maxillary Sinus ; Prognosis ; Retrospective Studies* ; Survival Rate*

The purpose of this study was to evaluate the success rate of Korean implant systems. A total of 245 implants were placed in 112 patients using different implant systems from February 1988 until June 2002. Data on implant systems, implant positions, surface treatments, guided bone regeneration procedure, marginal bone levels, and states of surrounding gingiva were collected. A follow-up evaluations were done after 1 year and 2 year of loading. Clinical parameters such as probing depth was evaluated at the last follow-up. The marginal bone loss after 1 year of loading was measured on periapical radiographs. Clinical comparisons were performed to evaluate implants loss in relation to the implant systems, implant positions, surface treatments, and guided bone regeneration procedure. There was no clinical difference of success rate in implant systems, implant positions, and surface treatments. Mean marginal bone resorption from the time of loading to 1 year follow-up was 0.31mm in Korean implant systems and 0.41mm in other implant systems. The cumulative survival rate of Korean implant systems and other implant systems at the 2-year of loading was 95.6% and 97.3% respectively. From these results, it was concluded that Korean implant systems could be successfully used in clinical dentistry.
Bone Regeneration ; Bone Resorption ; Dentistry ; Follow-Up Studies ; Gingiva ; Humans ; Retrospective Studies* ; Survival Rate

The success of an implant is determined by its integration into the tissue surrounding the biomaterial. Surface roughness is considered to influence the behavior of adherent cells. The aim of this in vitro study was to determine the effect of surface roughness on Saos-2 osteoblast-like cells. Titanium disks blasted with 75 micrometer aluminum oxide particles and machined titanium disks were prepared. Saos-2 were plated on the disks at a density of 50,000 cells per well in 48-well dishes. After 1 hour, 1 day, 6 days cell numbers were counted. One day, 6 days after plating, alkaline phosphatase(ALPase) activity was determined. Compared to experimental group, the number of cells was significantly higher on control group. The stimulatory effect of surface roughness on ALPase was more pronounced on the experimental group than on control group. These results demonstrate that surface roughness alters proliferation and differentiation of osteoblasts. The results also suggest that implant surface roughness may play a role in determining phenotypic expression of cells.
Aluminum Oxide ; Cell Count ; Osteoblasts* ; Titanium*

The purpose of this study was to evaluate the difference of subgingival bacterial compositions between periodontally healthy and diseased sites. Subgingival plaque samples were obtained from 100 sites in 20 untreated adult periodontitis patients(experimental group), and 100 sites in healthy individuals(control group). Before sampling, probing pocket depth(PPD) and clinical level of attachment(CAL), Plaque Index(PI), and Sulcus Bleeding Index(SBI) were recorded for each sampled sites. Microbial samples were collected from the bases of gingival sulci or periodontal pockets with sterile curettes. The samples were examined under darkfield microscope(x400). At least 150 bacteria were evaluated and categorized on the basis of bacterial morphology and motility, i.e. cocci, non-motile rods, motile rods, and spirochetes. In control group, subgingival microbial flora consisted of 73.7% of cocci, 20.0% of non-motile rods, 4.3% of motile rods, and 2.0% of spirochetes. The microbial samples from experimental group consisted of 51.5% of cocci, 19.4% of non-motile rods, 17.6% of motile rods, and 11.6% of spirochetes. The proportion of cocci was higher in control group than in experimental group. Proportions of motile rods and spirochetes were higher in experimental group than in control group. The proportion of nonmotile rods in experimental group and control group was not significantly different. Sulcus Bleeding Index and Plaque Index showed high correlation with the bacterial composition. These findings suggests that examination of subgingival bacterial proportion may serve as more sensitive mirror of the local periodontal status than clinical parameters.
Adult* ; Bacteria ; Chronic Periodontitis* ; Hemorrhage ; Humans ; Periodontal Pocket* ; Spirochaetales

PURPOSE: The aim of this study was to obtain objective and standardized information on masticatory function and patient satisfaction following second molar single implant therapy. METHODS: Twenty adult patients, who had restored second molar single implants more than 1 month before the study, were enrolled in this study. All patients received a chewing test using peanuts before and after insertion of the implant prosthesis, with a questionnaire and visual analogue scale (VAS) to evaluate the effect of second molar single implant therapy. RESULTS: This study obtained standardized information on the masticatory function objectively (e.g., P, R, X50) before (Pre-insertion) and after insertion (Post-insertion) of the implant prosthesis. Masticatory performance (P) after insertion of the implant prosthesis significantly increased from 67.8+/-9.9 to 84.3+/-8.5% (P<0.0001). With the implant prosthesis, the P value increased by 24%. The masticatory efficiency index (R) of Post-insertion is higher than that of Pre-insertion (P<0.0001). With the implant prosthesis, the R value increased by 29%. The median particle size (X50) of Post-insertion is lower than that of Pre-insertion (P<0.0001). More than 90% of the patients were satisfied with the second molar single implant therapy from a functional point of view. CONCLUSIONS: These findings indicate that a second molar single implant can increase masticatory function.
Adult ; Arachis ; Dental Implants, Single-Tooth ; Humans ; Mastication ; Molar ; Particle Size ; Patient Satisfaction ; Prostheses and Implants ; Surveys and Questionnaires

Amlodipine, nifedipine, and felodipine are calcium channel blocking agents, which are cause of unwanted gingival overgrowth around natural teeth. Many studies has been performed about this unwanted effects. However, the exact etiology remains uncertain.Few reports and investigations can be found in the literature on drug-induced gingival overgrowth around dental implants. The present case reports that amlodipine-induced gingival overgrowth occurred in peri-implant sites, confirms clinical and histological features in hyperplastic peri-implant tissues. Clinical and histological features of amlodipine-induced gingival overgrowth around dental implants were similar to that of tissue around natural teeth.