No abstract available.

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

No abstract available.
Chlorhexidine* ; Guided Tissue Regeneration*

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

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 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*

For histologic observation of the regenerated bone following guided tissue regeneration(GTR) using ePTFE membranes with calcium carbonate implant and autogenous bone graft, biopsies were collected from 2 patients during 5-year-postoperative surgical reentry. In both combined cases with guided tissue regeneration in conjunction with calcium carbonate implant and autogenous bone graft, significant bone fill and gain in probing attachment level was observed. In histologic examination, specimen in GTR case with calcium carbonate grafting was composed of a dense bone containing vascular channel with lamellar structure and viable bone cells in lacunae, however considerable calcium carbonate particles remained unresorbed and isolated from regenerated bone by the dense cellular and fibrous connective tissue. No formative cells could be seen in contact with remained calcium carbonate particles. In GTR case with autogenous bone grafting, specimen show was composed of a dense lamellar bone containing vascular channel, which showed normal alveolar bone architectures. The present observation indicate that guided tissue regeneration in conjunction with grafting, especially autogenous bone graft, has highly osteogenic potential, however resorbable calcium carbonate granules were not completely resorbed at 5 year postimplantation.
Biopsy ; Bone Regeneration ; Bone Transplantation ; Calcium Carbonate* ; Calcium* ; Connective Tissue ; Guided Tissue Regeneration* ; Humans* ; Membranes ; Transplants*

Maxillary palatal mucosa is the most frequently used donor site of the soft tissue for periodontal plastic surgery. In our study, thickness of the palatal mucosa between the mesial side of the maxillary first premolars and the distal side of the maxillary first molars was measured with a periodontal probe and an ultrasonic device in 30 young Korean adults. Using the data, the possibility of the clinical application of ultrasonic devices was evaluated. The results of this study were as follow; 1. The thickness of the palatal mucosa of the maxillary premolars is the thickest and that of the mid-palatal portion of the maxillary first molar is the thinnest. 2. The thickness of the palatal mucosal tissue increases from the gingival margin to the mid-palatal suture. 3. The measurements of the periodontal probe and the ultrasonic device revealed the strong positive correlations.
Adult ; Bicuspid ; Humans ; Molar ; Mucous Membrane* ; Surgery, Plastic ; Sutures ; Tissue Donors ; Ultrasonics

The early exposure of cover screws is a common complication of 2-stage implant technique. The exposure of cover screws between stage I and II surgery may cause inflammation in the soft tissues surrounding the implants, and lead to peri-implantitis or marginal bone loss. The purpose of this study was to evaluate the effect of the early exposure of cover screws on implants placed using 2-stage technique. Two hundred and nineteen implants in 77 patients were examined for cumulative survival rate, radiographic marginal bone level change, cause and frequency of the early exposure. The results were as follows: 1. Twenty-five implants showed early exposure of cover screws with a frequency of 11.4%. 2. Cumulative survival rate of the implants with early cover screw exposure was 88.0%, and that of the implants without cover screw exposure was 96.9%. 3. At the time of stage II surgery and 1 year after loading, the marginal bone loss was greater around the implants with early exposure of cover screws than around the implants without cover screw exposure(p <0.05). 4. There was no statistically significant difference in the frequency of the early exposure according to the implant diameter, gender, and smoking(p >0.05).
Humans ; Inflammation ; Peri-Implantitis ; Survival Rate*