Effect of initial placement level and wall thickness on maintenance of the marginal bone level in implants with a conical implant-abutment interface: a 5-year retrospective study

PURPOSE: Implant wall thickness and the height of the implant-abutment interface are known as factors that affect the distribution of stress on the marginal bone around the implant. The goal of this study was to evaluate the long-term effects of supracrestal implant placement and implant wall thickness on maintenance of the marginal bone level. METHODS: In this retrospective study, 101 patients with a single implant were divided into the following 4 groups according to the thickness of the implant wall and the initial implant placement level immediately after surgery: 0.75 mm wall thickness, epicrestal position; 0.95 mm wall thickness, epicrestal position; 0.75 mm wall thickness, supracrestal position; 0.95 mm wall thickness, supracrestal position. The marginal bone level change was assessed 1 day after implant placement, immediately after functional loading, and 1 to 5 years after prosthesis delivery. To compare the marginal bone level change, repeated-measures analysis of variance was used to evaluate the statistical significance of differences within groups and between groups over time. Pearson correlation coefficients were also calculated to analyze the correlation between implant placement level and bone loss. RESULTS: Statistically significant differences in bone loss among the 4 groups (P<0.01) and within each group over time (P<0.01) were observed. There was no significant difference between the groups with a wall thickness of 0.75 mm and 0.95 mm. In a multiple comparison, the groups with a supracrestal placement level showed greater bone loss than the epicrestal placement groups. In addition, a significant correlation between implant placement level and marginal bone loss was observed. CONCLUSIONS: The degree of bone resorption was significantly higher for implants with a supracrestal placement compared to those with an epicrestal placement.

Association between Oral Health and Gastric Neoplastic Lesions

BACKGROUND/AIMS: Although several studies have suggested that tooth loss is associated with the risk of gastric cancer, the association between oral health and gastric cancer remains a controversial issue. Thus, we investigated whether oral health is associated with the risk of gastric neoplastic lesions. MATERIALS AND METHODS: We retrospectively evaluated 391 patients who underwent upper gastrointestinal endoscopic examination between March 2010 and February 2013. The tooth number and the age-related periodontal bone loss score (ArB score) were investigated as parameters of oral health. Gastric neoplastic lesions included adenomas and cancer detected on biopsy examination. RESULTS: We identified 10 patients (2.6%) with neoplastic lesions. Older age, a higher body mass index, and the presence of Helicobacter pylori infection were significantly associated with neoplastic lesions. However, there was no significant correlation about Kimura-Takemoto classification, ArB score, and tooth number. Multivariate analyses showed that age was significantly associated with neoplastic lesions. CONCLUSIONS: Our findings demonstrate that oral health (assessed using parameters such as tooth number and ArB score) may not be significantly associated with gastric neoplastic lesions.

Changes in the fractal dimension of peri-implant trabecular bone after loading: a retrospective study

PURPOSE: To assess bony trabecular changes potentially caused by loading stress around dental implants using fractal dimension analysis. METHODS: Fractal dimensions were measured in 48 subjects by comparing radiographs taken immediately after prosthesis delivery with those taken 1 year after functional loading. Regions of interest were isolated, and fractal analysis was performed using the box-counting method with Image J 1.42 software. Wilcoxon signed-rank test was used to analyze the difference in fractal dimension before and after implant loading. RESULTS: The mean fractal dimension before loading (1.4213+/-0.0525) increased significantly to 1.4329+/-0.0479 at 12 months after loading (P<0.05). CONCLUSIONS: Fractal dimension analysis might be helpful in detecting changes in peri-implant alveolar trabecular bone patterns in clinical situations.

The plaque-removing efficacy of a single-tufted brush on the lingual and buccal surfaces of the molars

PURPOSE: To test the plaque-removal efficacy of a single-tufted toothbrush on the posterior molars compared with a flat-trimmed toothbrush. METHODS: Forty-nine subjects were selected. Professional instruction and written brushing instructions were given. After thorough supra-gingival scaling and polishing, all subjects were asked to abstain from oral hygiene procedures for 24 hours prior to the first experiment. The subjects were randomized to a treatment sequence. The modified Quigley and Hein plaque index was recorded pre- and post-tooth brushing, at 6 surfaces of the posterior molars. After a wash-out period, all the remaining plaque was removed professionally. Twenty-four hours of brushing abstinence was again performed. The plaque index was recorded pre- and post-tooth brushing after the subjects were given the second toothbrush in the cross-over sequence. RESULTS: The percentage reductions in plaque scores achieved with the single-tufted brushes were significantly higher than those of the flat-trimmed brush at the maxillary buccal interproximal, marginal and mandibular lingual interproximal site. The other locations showed no significant difference. CONCLUSIONS: The results of the present study implied that the single-tufted brush could be an effective tool for the removal of plaque at some, but not all, sites of the posterior molars.

Comparison of Black-pigmented Bacteroides using 16S rRNA analysis between Chronic periodontitis and Aggressive Periodontitis / 대한치주과학회지

The purpose of the research is to compare the distribution of Black-pigmented Bacteroides between Chronic Periodontitis and Aggressive Periodontitis. P. gingivalis, P. intermedia and P. nigrescens were examined in order to evaluate their distribution in patients with Chronic Periodontitis(CP) and Aggressive Periodontitis(AP). PCR and dot-blots hybridization of 16S rRNA gene were used to compare bacterial distribution of two groups - CP group and AP group, which were divided into two subgroups. Subgingival plaque taken from the diseased sites(pocket depth> or =6 mm) and healthy sites(pocket depth< or =3 mm) were grouped into the experimental group and the control group. The result are as follows ; 1. The distribution of P. gingivalis was 98.33% for chronic Periodotitis(CP), 94.17% for Aggressive Periodontitis(AP), the distribution of P. intermedia was 77.50% for CP, 64.17% for AP, and the distribution of P. nigrescens was 35.00%, 29.17%. In all 3 types of bacteria, CP group showed higher distribution compared to AP group, but only P. intermedia showed statistically significant difference. 2. In the case of CP, every type of bacteria showed higher distribution in the experimental group with statistically significant difference. 3. In the case of AP, every type of bacteria also showed higher distribution in the experimental group, but P. gingivalis and P. .intermedia showed the result with statistically significant difference, and the other did not 4. In 3 all bacteria type, N-AP showed higher distribution than N-CP without statistically significant difference These results suggest that the comparison of the distribution of Bacteroides between Chronic Periodontitis and Aggressive Periodontitis has no statistically significant difference, except P. intermedia.

THE BONE REGENERATIVE EFFECTS OF PARADIOXANONE ON THE CALVARIAL CRITICAL SIZE DEFECT IN SPRAGUE DAWLEY RATS / 대한치주과학회지

The major goals of periodontal therapy are the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. Bone graft & guided tissue are being used for the regeneration of destroyed periodontium these days. Non-resorbable membranes were used for Guided tissue regeneration in early days, however more researches are focused on resorbable membranes these days. The aim of this study is to evaluate the osteogenesis of paradioxanone membrane on the calvarial critical size defect in Sprague Dawley rats. An 8 mm diameter surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into three groups: Untreated control group, Biomesh(R) group and paradioxanone group. The animals were sacrificed at 4, 8 and 12 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric analyses. The results are as follows: 1. In histological view on Biomesh(R), no visible signs of resorption was observed at 4 weeks but progressive resorption was observed at 8 weeks through 12 weeks. Paradioxanone membrane expanded at 4 weeks, and rapid resorption was observed at 8 weeks. In both the membranes, inflammatory cells were observed around them. Inflammatory cells decreased with time but were still present at 12 weeks. More inflammatory cells were observed in paradioxanone membranes than in Biomesh(R) membrane. 2. The area of newly formed bone in the defects were 0.001+/-0.001, 0.006+/-0.005, 0.002+/-0.003 at the 4 weeks, 0.021+/-0.020, 0.133+/-0.073, 0.118+/-0.070 at the 8 weeks and 0.163+/-0.067, 0.500+/-0.197, 0.487+/-0.214 at the 12 weeks in the control group, Biomesh(R) group and experimental group respectively. Compared to the control group, Biomesh(R) group displayed significant differences at 4,8, and 12 weeks and the paradioxanone group at 8 and 12 weeks.(P<0.05) 3. The area of residual membranes were 1.143+/-0.499, 2.599+/-1.012, at the 4 weeks, 0.666+/-0.140, 0.314+/-0.131 at the 8 weeks and 0.365+/-0.110, 0.076+/-0.050 at the 12 weeks in the Biomesh(R) group and experimental group respectively. Between the two groups, significant differences were displayed at 4 weeks.(P<0.05) According to the results, when paradioxanone membrane was used in calvarial critical size defect in Sprague Dawley rat, initially the membrane expaned and regeneration of newly formed bone was small however after 8weeks new bone was formed with simultaneous resorption for the membrane. If a few problems could be solved, previously used membranes could be replaced in periodontal guided tissue regeneration.

An 1 year prospective comparative study evaluating the effect of microthread on the maintenance of marginal bone level / 대한치주과학회지

The success of dental implant therapy relies mainly upon the presence and maintenance of bone adjacent to implant. An 1-year prospective study was performed, upon the patients who were diagnosed as having chronic adult periodontitis, and had been treated with dental implant. The purpose of this study was to measure the radiographic bone level changes proximal to Astra Tech Single Tooth Implants (ATST, Astra Tech AB, MOlndal, Sweden) with microthread and Astra Tech TiOblast Implant (ATTB) without microthread supporting fixed partial prosthesis. Measurements were used to determine mean marginal bone loss during the first year of loading. 17 subjects with its partial prosthesis supported by 37 implants were followed up for an 1-year period. The marginal bone loss of implants was positively correlated with the retention factor, microthread (Microthread(TM)) in crestal area of ATST. The results were as follows. 1. The mean marginal bone loss of ATST was 0.226+/-0.395mm, while ATTB was 0.440+/-0.360mm. There was a statistically significant difference between ATST and ATTB (p0.05). 3. The mean bone loss of ATST was lower than that of ATTB at all sites according to bone quality. There was a statistically significant difference between ATST and ATTB at bone quality type III (p<0.05). In conclusion, the mean bone loss of ATST was smaller than that of ATTB. Therefore, the retention factor of crestal area, microthread (Microthread(TM)) was effective to maintenance of marginal bone level around fixture.

The retrospective study of the prognosis of implants in chronic periodontitis patients / 대한치주과학회지

The successful use of osseointegrated implants to replace missing teeth has been demonstrated for both the completely and the partially edentulous patients. Many studies have confirmed an excellent long- term prognosis. The successful outcome of any implant procedure is surely dependent on the interrelationship of the various components that includes the following: biocompatibility of the implant material, macroscopic and microscopic nature of the implant surface, the status of the implant bed in both a health(noninfected) and a morphologic(bone quality) context, the surgical technique, the undisturbed healing phase, the subsequent prosthetic design, and long-term loading phase. Periodontally compromised patients have poor status of the implant bed and periodontal pathogen. No longitudinal data are available whether these factors affect the prognosis of implants. In this study, 102 machined Branemark implants are inserted to analyze the success rate of 1-4 years and marginal bone loss in 49 chronic periodontitis patients. The following conclusions could be drawn from this study. 1. The cumulative success rate of implants at the 4-year of loading was 95.10%. 2. 5 failed implants have been removed. One implant have been removed due to infection, two implants were removed due to failure of osseointegration. and other two implants were removed due to mechanical failure caused by over-loading. 3. Mean marginal bone loss from the time of loading was 0.94mm at first year, 1.12mm at second year, 1.25mm at third year. These results suggest that implant therapy is good treatment modality in chronic periodontitis patients, and periodontal treatment including oral hygiene program is completed prior to insertion of implants.

A Retrospective study on upper single tooth implants / 대한치주과학회지

The aim of this retrospective study was to compare the amount of marginal bone loss between upper anterior area and upper posterior area with 71 upper single-tooth restorations on 2 stage machined Branemark implants since Jan 1995. The second aim was to compare the bone defect group which had dehiscence and fenetration and the others in the upper anterior region. The results were as follows. 1. The most frequent reason of missing tooth in the upper anterior region was trauma by 61%. While upper posterior region showed various reasons such as congenital missing, advanced periodontitis, trauma. 2. Peri-implantitis with fistula occurred 1 of 41 implants in the upper anterior group in 1 year after loading and 2 of 32 implants in the upper posterior group failed before loading. The 1 year success rate of upper anterior group was 97.56 %, and 93.75 % for upper posterior group. 3. The mean marginal bone loss in the upper anterior group was 0.44 +/- 0.25 mm, while 0.57+/- 0.32 mm in the upper posterior group. There was stastically significant difference in the amount of mean marginal bone loss (P<0.05). 4. The mean marginal bone loss of bone defect group was 0.40+/- 0.10 mm at one year, and 0.48+/- 0.26 mm for the control group. No statistically significant difference of mean marginal bone loss was showen between bone defect group and the others at implantation. According to the results, the upper anterior region showed less marginal bone loss than the upper posterior region. In case of missing single upper tooth, careful consideration on recipient residual ridge to determine proper implant diameter and length, sufficient healing time, proper loading would lead to implant success. Single tooth implants in the maxilla seemed to be an alternative to fixed partial dentures without damage to adjacent teeth.

The comparison between 2 wide implants and 3 regular implants in mandibular posterior area / 대한치주과학회지

Osseointegrated implants have been established as the standard treatment modality for full/partial edentulous patients since the 1960's, and the long term results for full edentulous patients have proven to be successful. Based on these results osseointegrated implants are now widely used for partial edentulous patients. There has been an increased interest towards the efficacy of wide implants, despite many reports mentioning the lower success rate of wide implants compared to regular implants. Recently, mandibular molar area defects are commonly restored using 2 wide implants, but it is not determined whether which treatment modality-3 regular implants or 2 wide implants-shows superior success rate. In this study, 2 wide implants and 3 regular implants used for the restoration of mandibular molar area are used to compare the survival rate of 1-4 years, and to analyze and compare the failure factors. The following conclusions could be drawn from this study. 1. Wide implants and regular implants showed 94.5% and 97,6% of survival rate respectively. After prosthodontic work, the survival rate was 100% and 98.1% for wide implants and regular implants respectively. 2. 5 failed implants have been removed. 2 wide implants and 1 regular implant have been removed due to failure of osseointegration, 1 wide implant was removed due to abscess formation caused by over-heating, and 1 regular implant was removed due to mechanical failure caused by over-loading within the first year of function. 3. No statistically significant difference was observed with respect to the amount of marginal bone loss of wide and regular implants.(P>0.05) In conclusion, restoration of the mandibular molar area using 3 regular implants was found to be a good treatment modality, and 2 wide implants could be considered a good treatment modality when success factors are taken into account.

The characteristics of Korean multi-rooted teeth root trunk extracted by periodontal disease / 대한치주과학회지

The purpose of this study was to investigate the characteristiss of korean multi-rooted teeth extracted by periodontal disease. A total of 182 extracted multi-rooted teeth were examined. The distance from the cementoenamel junction(CEJ) to the root groove and from the CEJ to the root division was measured. The frequency of the root grooves were calculated. The results are as follows : 1. Distances from CEJ to the root groove were 1.53, 1.60mm for maxillary first premolars mesial, distal sides, 1.26, 1.38, 1.75mm for maxillary first molars buccal, mesial, distal sides, 1.38, 1.71, 1.41mm for maxillary second molars buccal, mesial, distal sides, 0.98, 0.99mm for mandibular first molars buccal , lingual sides and 1.28, 1.35mm for mandibular second molars buccal, lingual sides. 2. The frequency of the root grooves were 17.4, 30.4% for maxillary first premolars mesial, distal sides, 44.4, 84.1, 67.5% for maxillary first molars buccal, mesial, distal sides, 100, 90.3, 90.3% for maxillary second molars buccal, mesial, distal sides, 42.9, 77.8% for mandibular first molars buccal, lingual sides and 90.6% for mandibular second molars buccal, lingual sides. 3. Distances from CEJ to the root division were 6.8, 7.2mm for maxillary first premolars mesial, distal sides, 3.3, 4.38, 4.34mm for maxillary first molars buccal, mesial, distal sides, 3.67, 4.8, 4.07mm for maxillary second molars buccal, mesial, distal sides, 3.1, 3.89mm for mandibular first molars buccal, lingual sides and 3.2, 4.06mm for mandibular second molars buccal, lingual sides.

The effect of flap operation and metronidazole gel combined therapy on the treatment of the juvenile periodontitis / 대한치주과학회지

The aim of the study was to investigate the effect of surgical therapy combined with the usage of metronidazole gel in the treatment of juvenile periodontitis by comparing clinical indices of flap operation along with application of metronidazole gel and flap operation only. Comparing clinical indices of the baseline, 3 months after surgery, 6 months after surgery statistically, the results are as follows; 1. Bleeding on probing (BOP) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p0.05). However, there was no statistically significant difference in these groups (p>0.05). 2. Pocket probing depth (PPD) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p0.05). However, there was no statistically significant difference in these groups (p>0.05). 3. Loss of attachment level(LOA) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p0.05). In conclusion, flap operation was effective on the treatment of juvenile periodontitis. However, combined therapy of metronidazole gel could not give rise to any significant adjunctive effect on the treatment outcome.

The Effect of Treponema Denticola and Treponema Lecithinolyticum on Periodontal Ligament Cells / 대한치주과학회지

This study was investigated to observe the effect of Treponema denticola(TDC) and Treponema lecithinolyticum(TLC) on cultured human periodontal ligament cells. Several experiments were performed including MTT test for the inhibition effect of cell proliferation, LDH test for the cytotoxicity , gelatin zymography for the gelatinase activation and observation of cell morphology change using the phase-contrast microscopy. The results were as follows. 1. The effect of concentration on cell proliferation with time showed an inhibitory effect at high concentration(150microgram/well) for TLC and at low concentration( 9.4microgram/well ) for TDC. 2. The effect of time on cell proliferation with concentration showed an inhibitory effect at 150microgram/well on 2-day incubation for TLC and at 9.4microgram/well on 2-day incubation for TDC. 3. The effect of heat-treated TDC and TLC on the inhibition of cell proliferation showed the difference in the heat-treated group compared to the non-heat treated group for TDC, whereas no difference was found for TLC. 4. The morphological changes which were observed from the phase-contrast microscopy showed the difference in the test group compared to the control group. The loss of spindle-like appearance, cell-to-cell detachment and inhibition of cell proliferation were observed. 5. There was no difference of the cytotoxicity effect between the test group and the control group in the LDH test. 6. The active form of progelatinase A with molecular weight 72kDa was activated in both TDC and TLC on the gelatin zymography. Regarding to the above results, TDC and TLC have an effect on periodontal ligament cells by playing an inhibitory role in cell proliferation and appears to activate progelatinase A which degrades type IV collagen.

Clinical study on the width of attached gingiva the subjects with healthy gingiva, or early stage of gingivitis / 대한치주과학회지

The purpose of this study was to investigate the width of attached gingiva of 414 subjects with healthy gingiva, or early stage of gingivitis. We compared the differences according to the tooth location, age (Yonger group : 14~30, Older group : 31~67) and gender. In addition, we compared the width of attached gingiva in the subjects with less than 2 sites of gingival recession(Re or =3) to study the relationship between the gingival recession and the width of attached gingiva. The results were as follows : 1. The width of keratinized gingiva was widest in maxillary incisors(5.3+/-1.4mm) and narrowest in mandibular right 1st bicuspid and mandibular right and left 2nd molars(3.5+/-1.1mm). 2. The width of attached gingiva was widest in maxillary right central incisor(3.8+/-1.5mm) and narrowest in mandibular right 2nd molar(1.2+/-1.0mm). 3. In the comparison between the age groups, the width of keratinized in older group was significantly(p<0.05) wider than that in younger group in maxillary right and left 1st bicuspids, mandibular right and left 1st and 2nd molars, maxillary right and left cuspids and mandibular right 1st bicuspid. There was no significant difference in the width of attached gingiva between the two groups except for maxillary right and left 1st molars and maxillary left 2nd molar. 4. In the comparison between male group and female group, in maxillary right and and left lateral incisors and cuspids, mandibular right and left cuspids and 1st bicuspids, the width of attached gingiva in female was significantly(p<0.05) wider than that in male group. 5. In the comparison between the Re 3 group and Re 2 group, there was no significant difference except for maxillary right and left 2nd molars and maxillary left 1st molar. 6. The frequency of gingival recession was in the order of mandibular right 1st bicuspid(16.6%), maxillary right 1st bicuspid(13.7%), maxillary and mandibular left 1st bicuspids(13.4%), mandibular left cuspid(10.5%), maxillary left and mandibular right cuspids(10.1%) and maxillary right cuspid(7.9%).

The Effects of Calcium sulfate Membrane on the Periodontal Wound Repair of Horizontal Dehiscence defects in Dogs / 대한치주과학회지

The present study investigates the effects of calcium sulfate graft on the periodontal healing in intrabony periodontal defects of dogs. Following the general anesthesia with 30mg/kg pentobarbital injected intravenously, the first premolar was extracted and full-thickness periodontal flap was elevated from the second premolar to the fourth premolar. The portion of premolars coronal to the alveolar crest was removed and mesial and distal roots were separated. Exposed root canals were sealed with Caviton and covered completely with flaps sutured. Following the healing period of 12 weeks, the surgical sited were uncovered and 4x4mm intrabony defects were surgically created. Those defects with calcium sulfate graft following the root planing was designated as the test sites and those with flap surgery-only were designated as control sites. The animals were sacrificed after 8 weeks and the healing was histologically analyzed. The results were as follows. 1. No foreign body reaction or inflammation were observed in either groups. Calcium sulfate was completely resorbed in the test sites. 2. New cementum was observed coronal to the notch in both groups. Connective tissue fibers were oriented parallel to the root surface in the controls. Connective tissues were formed in large amount in the sites. 3. Test sites showed marked amount of new bone formation while the control sites showed minimal bone gain. 4. Root resorption was observed in coronal portions of th control sites. The results suggest that calcium sulfate is a biocompatible graft material with a potential for new bone and cementum formation.

The Effects of Graft of DFDB combined with Calcium Sulfate membrane on the Periodontal Wound Healing of Horizontal Dehiscence Defects in Dogs / 대한치주과학회지

The present study investigates the effects of DFDB graft combined with Calcium sulfate membrane on the periodontal wound healing in dehiscence defects of dogs. Following the initiation of general anesthesia by I.V. administration of 30mg/kg of pentobarbital, first premolar was extracted and full-thickness flap was elevated from the second to the fourth premolar. The portion of premolars coronal to the alveolar crest was removed and mesial and distal roots separated to produce single rooted teeth. Exposed root canals were sealed with Caviton and covered completely with flaps sutured. Following the healing period of 12 weeks, the surgical sites were uncovered and 4x4mm dehiscence defects were surgically created. Those defects with DFDB graft combined with Calcium sulfate membrane following root planing, were designated as test sites and those with flap surgery-only were designated as controls. 1. No foreign-body reaction or inflammation were observed in either groups. Calcium sulfate was completely resorbed in the test sites. 2. Significantly greater amounts of new cementum was observed in test sites compared with the controls. Significant amounts of functionally orientated collagens were observed in the test sites. 3. New bone formation was observed in significantly greater amounts in test sites. The results suggest that combined graft of DFDB and calcium sulfate is extremely biocompatible with a potential for new bone and cementum formation, and functional alignment of periodontal ligaments.

The Effects of calcium sulfate on healing of 1-wall intrabony defects in dogs / 대한치주과학회지

The main goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal diseases. Although conventional forms of periodontal therapy show sound clinical results, the healing results in long junctional epithelium. There have been numerous materials and surgical techniques developed for new attachment and bone regeneration. Bone grafts can be catagorized into; autografts, allografts, xenografts and bone substitutes. Synthetic bone substitute materials include hydroxyapatite, tricalcium phosphate, calcium carbonate, and Plaster of Paris. Calcium sulfate has found its use in dental practice for the last 30 years. Recent animal studies suggest that periodontal regeneration in 3 wall intrabony defect may be enhanced by the presence of calcium sulfate. And it is well known that 2 wall & 1 wall defect have less osteogenic potential, So we need to study the effect of calcium sulfate in 1 wall intrabony defect in dogs. The present study evaluates the effects of calcium sulfate on the epithelial migration, alveolar bone regeneration and cementum formation in intrabony defects of dogs. Four millimeter-deep one-wall intrabony defects were surgically created in the mesial aspect of anterior teeth and mesial & distal aspects of premolars. The test group received calcium sulfate grafts with a flap procedure. The control underwent flap procedure only. Histologic analysis following 8 weeks of healing revealed the following results: 1. The lengths of junctional epithelium were; 2.52mm in the control, and 1.89mm in the test group. There was no statistical significance between the two groups. 2. Alveolar bone formation were; 0.61mm in the control, and 1.88mm in the test group. There was a statistically significant difference between the two groups (p<0.05). 3. Cementum formations were; 1.1mm in the control, and 2.46mm in the test group. There was a statistically significant difference between the two groups (p<0.05). 4. The length of CT adhesion were; 0.97mm in the control, and 0.17mm in the test group. There was no statistically significant differences between the two groups These results suggest that the use of calcium sulfate in intrabony defects has little effect on junctional epithelium migration, but has significant effects on new bone and new cementum formations.

The Effect of Calcium Sulfate on the Periodontal Healing of 2-Wall Intrabony Defects in Dogs / 대한치주과학회지

The purpose of this study is to evaluate the regenerative potential of calcium sulfate in the treatment of 2-wall intrabony defects as compared to the flap procedure alone. Periodontal healing of surgically created 2-wall intrabony defects grafted with calcium sulfate were evaluated in dogs. Experimental 2-wall intrabony defects of 4x4x4mm were surgically created in the upper anterior edentulous areas between the canines. The test sites include four 2-wall intrabony defects in 4 dogs treated with a calcium sulfate graft. Another four 2-wall intrabony defects in 4 dogs were treated with flap surgery alone as the control sites. Healing was evaluated after 8 weeks. Apical extention of junctional epithelium(JE) was 2.29mm in the control group and 0.50mm in the test group. The length of connective tissue adhesion(CTA) was 0.53mm in the control group and 1.16mm in the test group. The length of new cementum(NC) was 1.17mm for the control group and 2.55mm for the test group. The length of new bone(NB) was 1.02mm in the control group and 2.27mm for the test group. The test group showed statistically significant differences from the control group in junctional epithelium extension, new cementum and new bone formations (p<0.05). Within the limitations of the present study, the results suggest that calcium sulfate may be a safe and cost-effective bone graft material for the treatment of intrabony periodontal defects.