Role of collagen membrane in lateral onlay grafting with bovine hydroxyapatite incorporated with collagen matrix in dogs

PURPOSE: The objective of this study was to elucidate the role of collagen membranes (CMs) when used in conjunction with bovine hydroxyapatite particles incorporated with collagen matrix (BHC) for lateral onlay grafts in dogs. METHODS: The first, second, and third premolars in the right maxilla of mongrel dogs (n=5) were extracted. After 2 months of healing, two BHC blocks (4 mmx4 mmx5 mm) were placed on the buccal ridge, one with and one without the coverage by a CM. The animals were sacrificed after 8 weeks for histometric analysis. RESULTS: The collagen network of the membranes remained and served as a barrier. The quantity and quality of bone regeneration were all significantly greater in the membrane group than in the no-membrane group (P<0.05). CONCLUSIONS: The use of barrier membranes in lateral onlay grafts leads to superior new bone formation and bone quality compared with bone graft alone.

Darkfield microscopic study of the bacterial morphotypes in the periodontal pockets of Korean adult periodontitis patients / 대한치주과학회지

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.

Melanin Pigmentation In Gingiva / 대한치주과학회지

Oral melanin pigmentation is common in some races and ethnic groups. The gingivae are the most frequently pigmented intra-oral tissues. Melanin pigmentation is the result of melanin granules, produced by melanoblasts intertwined between epithelial cells at the basal layer of the epithelium. We present one case of melanin pigmentation of the gingiva of 26-year old female. Melanin depigmentation method is applying a 90% phenol solution to deepithelize pigmented areas, gingivectomy, epithelial abrasion, bone denudation, and split thickess flap. We chose epithelial abrasion using round diamond bur. The patient satisfies the result and have almost no pain and discomfort. But repigmentation potential must be noticed to patient.

Effects of enamel matrix derivative and titanium on the proliferation and differentiation of osteoblasts / 대한치주과학회지

Among objectives of periodontal therapy, the principal one is the morphological and functional reconstruction of lost periodontal supporting tissues. This includes de novo formation of connective tissue attachment and the regrowth of alveolar bone. The use of enamel matrix derivative(EMD) may be a suitable means of regeneration new periodontal attachment in the infrabony defects. Implant used to replace lost tooth but, implantitis occurred after installation. The purpose of this study was to investigate the effects of EMD on differentiation and growth of osteoblast in titanium disc. Twentyfive millimeter diameter and 1mm thick Ti disc which was coated 25, 50, 100, 200microgram/ml of EMD(Emdogain(R)) used as experimental group, 25, 50, 100, 200ng/ml of rhBMP-2 as positive control group, and no coat as negative control group. A human osteosarcoma cell line Saos-2 was cultured in Ti disc and cell proliferation and Alkaline phosphatase (ALP) activity were measured at 1 and 6 days. PCR was performed at 2 and 8 hours. Semi-quantitative RT-PCR for mRNA expressions of various osteoblastic differentiation markers - type I collagen, ALP, osteopontin, and bone sialoprotein - were performed at appropriate concentrations based upon the results of MTT and ALP assay. Cultured cell-disc complexes were prepared for scanning electron microscopy (SEM) at 2 hour. Data were analyzed using Mann-Whitney and repeated- measures 1-way analysis of variance(SPSS software version 10,SPSS, Chicago, IL). After culture, there was more osteoblast in EMD100microgram/ml than in EMD50, 200microgram/ml on day 6. There was significant difference in experimental and positive control group compared control group, as times go by(1 and 6 days). Alkaline phosphatase activity was different significantly in EMD100, 200microgram/ml and BMP100, 200ng/ml on day 6. The results of reverse transcriptase-polymerase chain reaction (RT-PCR) showed that expression of mRNA for ALPase, collagen type I, osteopontin, bone sialoprotein and BMP-2 was detected at 2 hour and 8 hour in EMD200microgram/ml subgroup and BMP100ng/ml subgroup. The results of this study suggest that application of enamel matrix derivative on osteoblast attached to titanium surface facilitate the expression of bone specific protein and the differentiation and growth of osteoblast.