The influence of diabetes mellitus on periodontal tissues: a pilot study

PURPOSE: The purpose of this study was to preliminarily evaluate the influence of diabetes mellitus (DM) on periodontal tissue without establishment of periodontitis. METHODS: Seven-week-old db/db mice were used for the diabetic experimental group and systematically healthy mice of the same age were used as controls. After 1 week of acclimatization, the animals were sacrificed for hard and soft tissue evaluation. The pattern of bone destruction was evaluated by stereomicroscope evaluation with alizarin red staining and radiographic evaluation by microscopic computerized tomography images. Histological evaluation was performed with hematoxylin and eosin stain for evaluation of soft tissue changes. RESULTS: In both stereomicroscope evaluation and radiograph image analysis, aggressive form of bone destruction was observed in diabetic animals when compared to the systematically healthy controls. In histological evaluation, apical migration of junctional epithelium with slight inflammatory cell infiltration was observed with disarrangement of connective tissue fibers. CONCLUSIONS: Within the limits of this study, diabetic animals presented distortion in periodontal attachment and an aggressive bone loss pattern when compared to the healthy controls, suggesting that DM has an independent effect on periodontal tissue destruction irrespective of the presence or absence of periodontal disease.

Spontaneous healing capacity of rabbit cranial defects of various sizes

PURPOSE: This study evaluated the spontaneous healing capacity of surgically produced cranial defects in rabbits with different healing periods in order to determine the critical size defect (CSD) of the rabbit cranium. METHODS: Thirty-two New Zealand white rabbits were used in this study. Defects of three sizes (6, 8, and 11 mm) were created in each of 16 randomly selected rabbits, and 15-mm defects were created individually in another 16 rabbits. The defects were analyzed using radiography, histologic analysis, and histometric analysis after the animal was sacrificed at 2, 4, 8, or 12 weeks postoperatively. Four samples were analyzed for each size of defect and each healing period. RESULTS: The radiographic findings indicated that defect filling gradually increased over time and that smaller defects were covered with a greater amount of radiopaque substance. Bony islands were observed at 8 weeks at the center of the defect in both histologic sections and radiographs. Histometrical values show that it was impossible to determine the precise CSD of the rabbit cranium. However, the innate healing capacity that originates from the defect margin was found to be constant regardless of the defect size. CONCLUSIONS: The results obtained for the spontaneous healing capacity of rabbit cranial defects over time and the underlying factors may provide useful guidelines for the development of a rabbit cranial model for in vivo investigations of new bone materials.

Histological characteristics of newly formed cementum in surgically created one-wall intrabony defects in a canine model

PURPOSE: Periodontal regenerative therapies for defects created by severe periodontitis are mainly focused on bone regeneration. Although cementum regeneration needs to be better understood, it is believed to play an important role in periodontal regeneration. The first step toward a full understanding of cementum regeneration is to compare repaired cementum to pristine cementum. This study, which used histological techniques, was designed to focus on cementum regeneration and to compare pristine cementum to repaired cementum after surgical procedures with 8 and 24 week healing periods in a canine model. METHODS: Buccal and lingual mucoperiosteal flaps of 10 beagle dogs were surgically reflected to create critical-sized defects. Intrabony one-wall defects, of which dimension is 4 mm width and 5 mm depth, were made at the distal aspect of mandibular second premolars and the mesial aspect of mandibular fourth premolars in the right and left jaw quadrants. Animals were sacrificed after 8 and 24 weeks post-surgery for histological specimen preparation and histometric analysis. RESULTS: The repaired cementum was composed mostly of acellular cementum and cellular mixed fiber cementum and was thicker in the apical area than in the coronal area. The acellular cementum of the supracrestal area appeared to be amorphous. The newly formed cellular cementum was partially detached from the underlying circumpulpal dentin, which implied a weak attachment between new cementum and dentin, and this split was observed to a lesser extent in the 24 week group than in the 8 week group. The vertical height of the repaired cementum was greater in the 24 week group than in the 8 week group. CONCLUSIONS: Within the limitations of this study, we can conclude that repaired cementum after root planing was mainly acellular cementum and cementum tissue that matured to a shape similar to pristine cementum as the healing progressed from 8 to 24 weeks.

A retrospective study of the dental implants placed in the controlled diabetes mellitus patients / 대한치주과학회지

PURPOSE: The aim of the present study was to analyze 7-year cumulative survival rate (CSR, %) of dental implants in the controlled diabetic patients and to evaluate the influence of the position, diameter and length of fixture, bone quality, age, gender and the method of maxillary sinus elevation on the survival rate. METHODS: The data of 342 placed implants in the 104 diabetic patients collected between 1995 and 2007 at the Department of Periodontology in Yonsei University Hospital were analyzed. RESULTS: Seven-year CSR of the 342 dental implants in the 104 controlled diabetic patients was 96.5%. The survival rates of the placed implants according the position have no statistically significant difference. The survival rates according to the length or diameter of the fixtures have no statistically significant difference. The survival rates according to the bone quality were 100% (Type I), 97.1% (Type II), 97.7% (Type III) and 85.7%(Type IV). The difference between the survival rate of Type I, II and III and that of Type IV was statistically significant. The survival rates according to patient gender were 96.8% (male), 95.5% (female). The survival rates according to patient age were 100% ( or = 60). The survival rates according to the method of sinus elevation in the maxillary posterior area were 96.8% (without sinus elevation), 92.9% (lateral approach) and 89.8% (crestal approach). CONCLUSIONS: Dental implants can be used successfully in the controlled diabetic patients. In case of upper posterior region which has poor bone density and older patients, the implant treatment should be more properly planed, executed, and followed-up.

The effects of bone regeneration in rabbit calvarial defect with particulated and block type of hydroxyapatite / 대한치주과학회지

PURPOSE: The purpose of this study was to evaluate the bone regeneration of particulated hydroxyapatite(HA) and block type of hydroxyapatite graft in rabbit calvarial defects. METHODS: An 8 mm calvarial circular defects were created in sixteen young adult New Zealand white male rabbits (weight 3.0~3.5 kg). Each defects were filled with Bio-Oss, particulated HA and block type HA. Sham surgery control defects were filled with blood clots. The pecimens were harvested at 4 weeks and 8 weeks for histologic and histomorphometric evaluation. RESULTS: Histomorphometric analysis demonstrated statistical differences in defect closure, new bone formation, and bone density of the four groups. Block type of HA group showed increased bone formation and bone density at 4 weeks and 8 weeks compared with Bio-Oss group or sham surgery control group(p<0.05). CONCLUSIONS: Block type of HA is an effective material for osteoconduction in rabbit calvarial defects, which may acts as a guide in use of these products in human application.

A retrospective study of survival rate of dental implants placed in osteoporosis patients / 대한치주과학회지

PURPOSE: The presented study aims to evaluate the effects of osteoporosis on dental implants by analyzing a 12-year cumulative survival rate of implants placed in patients with osteoporosis. METHODS: 37 patients with history of osteoporosis were selected from a pool of dental implant patients treated at the Department of Periodontology in Yonsei University Hospital between 1993 and 2007. The cumulative survival rate is quantified using data collected from 164 placed implants in the selected 37 patients. RESULTS: 3 out of the 164 implants failed and the cumulative survival rate was observed at 95.1%. The survival rates of the implants according to patients' age were 97.41% (<60) and 100% (60< or =. The lower survival rate was directly proportional to younger age, and this relationship is statistically significant (P<0.05). The survival rates of implants according to diagnostic criteria were 95.45% (osteopenia) and 98.59% (osteoporosis; 2 out of 142 implants placed in osteoporosis patients failed). The difference in the two survival rates is statistically significant (P<0.05). The survival rates according to the region of implants do not have statistically significant difference. The survival rates according to the different length and diameter of the implants do not have statistically significant difference. The survival rates of implants accompanied and not accompanied by bone augmentation were 92.11% and 100%, respectively. The difference in the two survival rates is statistically significant (P<0.05). The survival rates of implants placed in patients with and without history of medication for osteoporosis treatment are 96.67% and 99.04%, respectively. The difference in the two survival rates is statistically significant (P<0.05). CONCLUSIONS: A high cumulative survival rate of dental implants, similar to one found in non-osteoporosis patients, is observed in osteoporosis patients, indicating the possibility that placing dental implants on patients with osteoporosis can be considered with high treatment predictability.

Effect of protein transduction domain fused-bone morphogenetic protein-2 on bone regeneration in rat calvarial defects / 대한치주과학회지

PURPOSE: Recombining bone morphogenetic protein (BMP) is usually acquiredfrom high level animals. Though this method is effective, its high cost limits its use. The purpose of this study was to evaluate the effect of bone morphogenetic protein-2 with protein transduction domain (BMP-2/PTD;TATBMP-2) on bone regeneration. Rat calvarial defect model and osteoblastic differentiation model using MC3T3 cell were used for the purpose of the study. MATERIALS AND METHODS: MC3T3 cells were cultured until they reached a confluence stage. The cells were treated with 0, 0.1, 1, 10, 100, 500 ng/ml of BMP-2/PTD for 21 days and at the end of the treatment, osteoblastic differentiation was evaluated usingvon Kossa staining. An 8mm, calvarial, critical-size osteotomy defect was created in each of 48 male Spraque-Dawley rats (weight 250~300 g). Three groups of 16 animals each received either BMP-2/PTD (0.05mg/ml) in a collagen carrier, collagen only, or negative surgical control. And each group was divided into 2 and 8 weeks healing intervals. The groups were evaluated by histologic analysis(8 animals/group/healing intervals) RESULT: In osteoblastic differentiation evaluation test, a stimulatory effect of BMP-2/PTD was observed in 10ng/ml of BMP-2/PTD with no observation of dose-dependent manner. The BMP-2/PTD group showed enhanced local bone formation in the rat calvarial defect at 2 weeks. New bone was observed at the defect margin and central area ofthe defect. However, new bone formation was observed only in 50% of animals used for 2weeks. In addition, there was no new bone formation observed at 8 weeks. CONCLUSION: The results of the present study indicated that BMP-2/PTD(TATBMP-2) have an positive effect on the bone formation in vitro and in vivo. However, further study should be conducted for the reproducibility of the outcomes.

Bone formation of newly developed biphasic calcium phosphate in rabbit calvarial defect model: A pilot study / 대한치주과학회지

PURPOSE: Biphasic calcium phosphates have been of great interest recently. Mixing adequate ratios of hydroxyapatite(HA) and beta-tricalcium phosphate(beta-TCP) allowed to control the resorption rate without distorting its osteoconductive property. This study evaluated the bone formation effect of newly developed biphasic calcium phosphate(BCP) in calvarial defect of rabbits. MATERIALS AND METHODS: 6 male New Zealand rabbits were used. Four defects with 8mm in diameter were created on each animal. BCP with HA/beta-TCP ratio of 7:3 and particle size of 0.5~1.0 mm was used as the test group and bovine bone with 0.25~1.0 mm particle size, as the control group. Both test and control group materials were randomly implanted in the calvarial defects and were covered witha polymer membrane. The animals were sacrificed after 12, 24, and 48 weeks of implantation under general euthanasia. Resin blocks were obtained and were stained by masson's trichrome for histological observation. RESULTS: Overall results were uneventful without any defect exposure or inflammation. The amount of new bone formation and bone maturity increased with increase in healing period at both groups. New bone in test group was mostly formed along the material particle surrounded by osteoblasts, and observation of osteoblastic stream was also present. Bone maturity increased as it was closer to thedefect margins. Under the same healing period, the test group showed more bone formation than the control group with more stable bovine bone particles remaining even after 48 weeks, whereas considerable resorption took place in BCP. Almost total defect closure was observed in test group with new bone formation in the central part of the defect. However, limited new bone formation was observed in the control group. CONCLUSION: Within the limits of the study, the present study reveals the newly developed BCP to be a good osteoconductive material. However, further studies are needed to be conducted in a different study model with a larger sample size.

Influence of the Sonic Power Toothbrush on Reduction of Gingival inflammation and on the Amount of Interleukin-6, Prevotella intermedia and Actinobacillus actinomycetemcomitans in Periodontal Pocket / 대한치주과학회지

No abstract available.

Efficacy of the Sonicare Elite(R) in plaque removal and reduction of gingival inflammation from hard-to-reach sites of the moderate periodontitis / 대한치주과학회지

The purpose of this study was to evaluate the efficacy of the Sonicare Elite(R) power toothbrush in plaque removal and reduction of gingivitis from hard-to-reach sites of the moderate periodontitis compared to regular manual toothbrush in 12 week follow-up. 82 subjects with incipient to moderate periodontitis were randomly assigned to use either the manual or sonic brush, instructed in its use, and asked to brush 2 times a day for 2 minutes. Plaque scores were taken at baseline, 1, 4, 12 weeks using Silness & Loe plaque index and gingival inflammation was assessed by the Loe & Silness gingival index. The results were as follows. 1. The Sonicare Elite(R) power toothbrush showed a significant reduction(p<0.0001) of the plaque( Silness & Loe) and gingival inflammation(Loe & Silness). 2. The Sonicare Elite(R) power toothbrush showed a significant better reduction of plaque and gingivitis(p<0.05) than the manual toothbrush after 1, 4, and 12 weeks. 3. The Sonicare Elite(R) power toothbrush demonstrated a significant reduction(p<0.0001) of the plaque in interproximal sites(p<0.0001), buccal sites(p<0.0001) and the lingual sites(p=0.0018) of the teeth. 4. The Sonicare Elite(R) power toothbrush demonstrated a significant reduction(p<0.0001) of the gingival inflammation in the interproximal sites(p<0.0001), the buccal sites(p<0.0001) and the lingual sites(p<0.0001) of the teeth. The results of this study support the findings that Sonicare Elite(R) power toothbrush has a great potential to remove the plaque and resolve the gingival inflammation during the period of 12 week.

Suppressive effect of Curcuma xanthorrhiza oil on plaque and gingivitis / 대한치주과학회지

To find out the suppressive effect of natural extract Curcuma xanthorrhiza on IL-1beta and MMP-2 derived from periodontal ligament cells through in vitro study and to confirm its effect on plaque and gingivitis through clinical study, Curcuma xanthorrhiza containing toothpaste was used and following results were produced. 1. In vitro study, type IV collagenase MMP-2 production was inhibited dose-dependently in the group treated with Curcuma xanthorrhiza compared to the control group. 2. In vitro study, the production of IL-1beta which is one of the inflammatory mediators associated with periodontitis was inhibited dose-dependently in the group treated with Curcuma xanthorrhiza. 3. On the third week, the plaque index of the groups treated with or without Curcuma xanthorrhiza containing toothpastes were both increased significantly compared to the baseline(p<0.05). 4. On the third week, the gingival index of the group treated with Curcuma xanthorrhiza containing toothpaste was not significantly different from baseline. However, the group treated without Curcuma xanthorrhiza containing toothpaste showed a significant increase of gingival index at shielded area(p<0.05). 5. The gingival index of the group without Curcuma xanthorrhiza containing toothpaste showed a significant increase in the sites without tooth brushing when compared to sites with tooth brushing(p<0.05). However, there was no significant difference for the group with Curcuma xanthorrhiza containing toothpaste in sites either with or without tooth brushing. 6. The Bleeding on probing for the group without Curcuma xanthorrhiza containing toothpaste showed no significant difference even when tooth brushing was done. However, for the group with Curcuma xanthorrhiza containing toothpaste, bleeding on probing was significantly reduced compared to baseline when tooth brushing was done(p<0.05).