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.

Development of the implant surgical technique and assessment rating system

PURPOSE: There has been no attempt to establish an objective implant surgical evaluation protocol to assess residents' surgical competence and improve their surgical outcomes. The present study presents a newly developed assessment and rating system and simulation model that can assist the teaching staffs to evaluate the surgical events and surgical skills of residents objectively. METHODS: Articles published in peer-reviewed English journals were selected using several scientific databases and subsequently reviewed regarding surgical competence and assessment tools. Particularly, medical journals reporting rating and evaluation protocols for various types of medical surgeries were thoroughly analyzed. Based on these studies, an implant surgical technique assessment and rating system (iSTAR) has been developed. Also, a specialized dental typodont was developed for the valid and reliable assessment of surgery. RESULTS: The iSTAR consists of two parts including surgical information and task-specific checklists. Specialized simulation model was subsequently produced and can be used in combination with iSTAR. CONCLUSIONS: The assessment and rating system provided may serve as a reference guide for teaching staffs to evaluate the residents' implant surgical techniques.

The biological effect of cyanoacrylate-combined calcium phosphate in rabbit calvarial defects

PURPOSE: The purpose of this study was to determine the biological effects of cyanoacrylate-combined calcium phosphate (CCP), in particular its potential to act as a physical barrier - functioning like a membrane - in rabbit calvarial defects. METHODS: In each animal, four circular calvarial defects with a diameter of 8 mm were prepared and then filled with either nothing (control group) or one of three different experimental materials. In the experimental conditions, they were filled with CCP alone (CCP group), filled with biphasic calcium phosphate (BCP) and then covered with an absorbable collagen sponge (ACS; BCP/ACS group), or filled with BCP and then covered by CCP (BCP/CCP group). RESULTS: After 4 and 8 weeks of healing, new bone formation appeared to be lower in the CCP group than in the control group, but the difference was not statistically significant. In both the CCP and BCP/CCP groups, inflammatory cells could be seen after 4 and 8 weeks of healing. CONCLUSIONS: Within the limits of this study, CCP exhibited limited osteoconductivity in rabbit calvarial defects and was histologically associated with the presence of inflammatory cells. However, CCP demonstrated its ability to stabilize graft particles and its potential as an effective defect filler in bone augmentation, if the biocompatibility and osteoconductivity of CCP were improved.

Periodontal regenerative effect of a bovine hydroxyapatite/collagen block in one-wall intrabony defects in dogs: a histometric analysis

PURPOSE: The aim of this study was to elucidate the effect of a bovine hydroxyapatite/collagen (BHC) block in one-wall intrabony periodontal defects in dogs. METHODS: A one-wall intrabony periodontal defect (4 mm wide and 5 mm deep) was prepared bilaterally at the mesial side of the mandibular fourth premolar in five beagle dogs. After thorough root planing, block-type BHC (4x5x5 mm) was placed on one side. The contralateral defect area did not receive any material as a sham-surgery control. Histological analysis of the sites was performed after an 8-week healing period. RESULTS: Two of five samples in the experimental group healed well without dissipation of the graft materials, and histological analysis revealed excellent regeneration of the periodontal tissues. However, most of the grafted materials had been displaced in the other three samples, leaving only a small portion of the graft. The measured parameters exhibited large standard deviations, and the mean values did not differ significantly between the experimental and sham-surgery control sides. CONCLUSIONS: The application of BHC alone-without a barrier membrane-to wide, one-wall intrabony periodontal defects yielded inconsistent results regarding both periodontal regeneration and substantivity of the graft materials. Thus, the use of a barrier membrane for noncontained-type defects is recommended to improve the stability of the grafted material, and to condense it.

Investigation of bone formation using calcium phosphate glass cement in beagle dogs

PURPOSE: Among available biomaterials, bioceramics have drawn special interest due to their bioactivity and the possibility of tailoring their composition. The degradation rate and formulation of bioceramics can be altered to mimic the compositions of the mineral phase of bone. The aim of this study was to investigate the bone formation effect of amorphous calcium phosphate glass cement (CPGC) synthesized by a melting and quenching process. METHODS: In five male beagle dogs, 4 x 4 mm 1-wall intrabony defects were created bilaterally at the mesial or distal aspect of the mandibular second and fourth premolars. Each of the four defects was divided according to graft materials: CPGC with collagen membrane (CM), biphasic calcium phosphate (BCP) with CM, CM alone, or a surgical flap operation only. The dogs were sacrificed 8 weeks post-surgery, and block sections of the defects were collected for histologic and histometric analysis. RESULTS: There were significant differences in bone formation and cementum regeneration between the experimental and control groups. In particular, the CPGC and BCP groups showed greater bone formation than the CM and control groups. CONCLUSIONS: In conclusion, CPGC was replaced rapidly with an abundant volume of new bone; CPGC also contributed slightly to regeneration of the periodontal apparatus.

Evaluating intra- and inter-examiner reproducibility in histometric measurement: one-wall intrabony periodontal defects in beagle dogs

PURPOSE: Accurate and exact measurement is an important factor for generating meaningful results in any properly designed study. If all the participating examiners are able to yield similar results, it will be possible to evaluate the objective results of the study more easily and quickly. The purpose of this study was to evaluate the intra- and inter-examiner reproducibility of histometric measurements in the intrabony periodontal defect model. METHODS: One wall intrabony defects were surgically created at the distal aspect of the second and the medial aspect of the fourth mandibular premolars in the right and left jaw quadrants in twenty beagle dogs and the defect sites received the following beta-tri calcium phosphate, growth differentiation factor-0, growth differentiation factor-100 and sham surgery. Histometric analysis was performed after 8 weeks. Histometric parameters were recorded and repeated at three months interval by three examiners. Intra- and inter-examiner reproducibility was assessed. RESULTS: Most parameters of all the groups showed high intra- and inter-examiner reproducibility. Parameters including defect height, bone regeneration height, cementum regeneration height, and formation of junctional epithelium yielded inter-examiner correlation > or = 0.9. The intra-examiner reproducibility showed a high result, over 0.9. CONCLUSIONS: Histometric evaluation of the one-wall intra-alveolar periodontal defect model showed high reproducibility not only for a single given examiner but also among the three examiners.

A simple approach to preserve keratinized mucosa around implants using a pre-fabricated implant-retained stent: a report of two cases

PURPOSE: There is no consensus regarding the relationship between the width of keratinized mucosa and the health of peri-implant tissues, but clinicians prefer to provide enough keratinized mucosa around dental implants for long-term implant maintenance. An apically positioned flap during second stage implant surgery is the chosen method of widening the keratinized zone in simple procedures. However, the routine suture techniques used with this method tend to apply tension over the provisional abutments and decrease pre-existing keratinized mucosa. To overcome this shortcoming, a pre-fabricated implant-retained stent was designed to apply vertical pressure on the labial flap and stabilize it in a bucco-apical direction to create a wide keratinized mucous zone. METHODS: During second stage implant surgery, an apically displaced, partial thickness flap with a lingualized incision was retracted. A pre-fabricated stent was clipped over the abutments after connecting to the provisional abutment. Vertical pressure was applied to displace the labial flap. No suture was required and the stent was removed after 10 days. RESULTS: A clinically relevant amount of keratinized mucosa was achieved around the dental implants. Buccally displaced keratinized mucosa was firmly attached to the underlying periosteum. A slight shrinkage of the keratinized zone was noted after the healing period in one patient, but no discomfort during oral hygiene was reported. Clinically healthy gingiva with enough keratinized mucosa was achieved in both patients. CONCLUSIONS: The proposed technique is a simple and time-effective technique for preserving and providing keratinized tissue around dental implants

The Effects of Hydroxyapatite-Chitosan Membrane on Bone Regeneration in Rat Calvarial Defects / 대한치주과학회지

PURPOSE: Recently, interest in chitosan has increased due to its excellent biological properties such as biocompatibility, antibacterial effect, and rapid healing capacity. On the other hand, hydroxyapatite is used as a bone substitute in the fields of orthopedics and dentistry. The hydroxyapatite-chitosan (HA-CS) complex containing hydroxyapatite nanoparticles was developed for synergy of both biomaterials. The objective of this study was to evaluate the effect of hydroxyapatite (HA)-chitosan (CS) membrane on bone regeneration in the rat calvarial defect. METHODS: Eight-millimeter critical-sized calvarial defects were created in 70 male Sprague-Dawley rats. The animals were divided into 7 groups of 10 animals and received either 1) chitosan (CS) 100% membrane, 2) hydroxyapatite (HA) 30%/ CS 70% membrane, 3) HA 30% / CS 70%, pressed membrane, 4) HA 40%/ CS 60% membrane, 5) HA 50%/ CS 50% membrane, 6) HA 50%/ CS 50%, pressed membrane, or 7) a sham - surgery control. The amount of newly formed bone from the surface of the rat calvarial defects was measured using histomorphometry, following 2- or 8- week healing intervals. RESULTS: Surgical implantation of the HA - CS membrane resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. The HA - CS membrane would be significantly more effective than the chitosan membrane in early bone formation. CONCLUSIONS: Concerning the advantages of biomaterials, the HA-CS membrane would be an effective biomaterial for regeneration of periodontal bone. Further studies will be required to improve the mechanical properties to develop a more rigid scaffold for the HA-CS membrane.

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.

Mechanism, prevention, risk assessment and treatment in bisphosphonates induced osteonecrosis of the jaw / 대한치주과학회지

PURPOSE: Bisphophonates are drugs used to suppress osteoclastic activity and to treat osteoporosis, Paget's disease of bone and bone metastasis. The purpose of this report is to review the literatures on bisphopsphonates use that could affect bone healing and cause osteonecrosis of the jaws. MATERIALS AND METHODS: Medline research was carried out to find relevant articles on bisphophonates and osteonecrosis of the jaw. RESULTS: Oral administration of bisphopsphonates is reported to decrease the risk of adverse bone outcomes. On the contrary, IV bisphopsphonates is known to significantly increase the risk. Prevention of the osteonecrosis of the jaw is primary concern before usage. If the adverse bone reaction takes place, proper management and treatments are required to alleviate pain of patients and prevent further progression of necrosis. CONCLUSION: Case reports of bisphosphonates induced osteonecrosis of the jaw are increasing. Dentists and physicians should be aware of the higher frequency of osteonecrosis of the jaw in patients receiving IV bisphopsphonates and be prepared to prevent and cope with adverse bone reaction.

Clinical case reports of cemental tear / 대한치주과학회지

PURPOSE: Cemental tear is an uncommon form of root fracture that can lead to rapid localized attachment loss. When it is exposed in the periodontal pocket, it should be removed to prevent accumulation of dental plaque and calculus. MATERIAL AND METHODS: 2 patients were diagnosed as a cemental tear and they were treated with conventional flap operation and subgingival curettage. Additional treatments such as bone graft or guided tissue regeneration were not performed. RESULT: Symptoms subsided after the treatment. Periodontal pocket has been reduced but no gain of clinical attachment was observed. Remnant of cemental fragment remained after curettage. However, periodontal pocket was stably maintained and there was no recurrence. CONCLUSION: Periodontal attachment loss associated with cemental tear can be successfully treated with conventional periodontal surgical and nonsurgical procedures.

Clinical crown lengthening procedure using surgical extrusion in esthetic region / 대한치주과학회지

PURPOSE: Various methods are used in clinical crown lengthening procedure. Esthetic is more important in anterior region than in posterior region. Therefore when performing clinical crown lengthening procedure in esthetic region, clinicians should choose method which doesn't impair esthetic. Surgical extrusion could be a good method to achieve esthetic results MATERIAL AND METHODS: Two patients were scheduled to clinical crown lengthening procedure in esthetic region. Teeth were extruded with periotome carefully to the intended level. Extruded teeth were anchored with sutures. Sutures are removed after 7day. Restorations were seated after extruded teeth were stabilized. RESULT: Five to six months later, both cases showed favorable esthetic outcome that were harmonious with adjacent teeth. CONCLUSION: When clinicians are to do clinical crown lengthening procedure in esthetic region, predictable esthetic outcome could be achieved with surgical extrusion.

Effect of Hydroxyapatite containing dentifrice on teeth hypersensitivity after periodontal therapy / 대한치주과학회지

PURPOSE: The purpose of this study was to evaluate the effects of hydroxyapatite containing toothpaste for patients who received periodontal therapy and felt hypersensiptivity. MATERIAL AND METHODS: After application of toothpaste, patients were evaluated for VAS(Visual Analog scale) scores to a cold stimulate on baseline, 1 week, and 4 weeks. VAS scores were analyzed by statistical methods. RESULTS: The results of this study were as follows. 1. VAS scores in control group on baseline, 1 week, 4 weeks were 5.39+/-2.05, 4.75+/-2.00, 4.21+/-1.75. 2. VAS scores in experimental group on baseline, 1 week, 4 weeks were 5.61+/-2.37, 4.81+/-2.46, 4.08+/-2.54. 3. Decrease of VAS scores on hypersensitivity after 1week was 0.64+/-0.49(p<.0001) in control group, 0.80+/-1.65 (p<.0001) in experimental group. 4. Decrease of VAS scores on hypersensitivity after 4weeks was 1.18+/-1.60(p<.0001) in control group, 1.53+/-1.88 (p<.0001) in experimental group. 5. When compared, decrease of VAS scores after 1 week between 2 groups were not statistically different(p=0.2622). 6. When compared, decrease of VAS scores after 4 weeks between 2 groups were not statistically different(p=0.1219). CONCLUSION: It was confirmed that hydroxyapatite containing toothpaste have the similar effect with pre-existing proven dentifrice for relieving teeth hypersensitivity.

Study of chitosan's effects on periodontal tissue regeneration: a meta-analysis of the histomorphometry / 대한치주과학회지

PURPOSE: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. MATERIALS AND METHODS: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. RESULTS: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. CONCLUSION: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

Effects of rhBMP-2 with various carriers on bone regeneration in rat calvarial defect / 대한치주과학회지

PURPOSE: Bone morphogenetic protein (BMP) is a potent differentiating agent for cells of the osteoblastic lineage. It has been used in the oral cavity under a variety of indications and with different carriers. However, the optimal carrier for each indication is not known. This study evaluated the bone regenerative effect of rhBMP-2 delivered with different carrier systems. MATERIALS AND METHODS: 8 mm critical-sized rat calvarial defects were used in 60 male Sprague-Dawley rats. The animals were divided into 6 groups containing 10 animals each. Two groups were controls that had no treatment and absorbable collagen membrane only. 4 groups were experimentals that contained rhBMP-2 only and applied with absorbable collagen sponge(Collatape(R)), MBCP(R), Bio-Oss(R) each. The histological and histometric parameters were used to evaluate the defects after 2- or 8-week healing period. The shape and total augmented area were stable in all groups over the healing time. RESULTS: New bone formation was significantly greater in the rhBMP-2 with carrier group than control group. rhBMP-2/ACS was the highest in bone density but gained less new bone area than rhBMP-2/MBCP(R) and rhBMP-2/Bio-Oss(R). The bone density after 8 weeks was greater than that after 2 weeks in all groups. However, rhBMP-2 alone failed to show the statistically significant difference in new bone area and bone density compared to control group. Also MBCP(R) and Bio-Oss(R) particles remained after 8 weeks healing period. CONCLUSION: These results suggest that rhBMP-2 with carrier system is an excellent inductive agent for bone formation and we can use it as the predictable bone tissue engieering technique. Future study will likely focus on the kinetics of BMP release and development of carriers that is ideal for it.

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.

Effects of various membranes on periodontal tissue regeneration: a meta-analysis of the histomorphometry / 대한치주과학회지

Various periodontal barrier membranes used in many clinical and experimental fields, and many recent studies of membranes have reported good results. To improve clinical results, selection of barrier membranes is an important factor. So, we need not only to evaluate various barrier membranes, but also to understand the property of barrier membranes appropriate to defect characteristics. For this purpose, this study reviewed available literature, evaluated comparable experimental models, and compared various barrier membranes. From above mentioned methods, the following conclusions are deduced. 1. In 1-wall periodontal defect models, new bone formation showed a consistent result, almost 30% of the defect size. New cementum formations measured mostly 40% of the defect size, but showed more variations than new bone formations. This seems to be resulted form difference in experimental methods, so standardization in experimental methods is needed for future studies. 2. Application PLGA barrier membrane to periodontal defect demonstrated improved healing in new bone and new cementum. 3. There was a minimal periodontal regeneration with calcium sulfate barrier membrane only. But, there was better healing pattern in combination of calcium sulfate membrane with bone graft material, such as DFDBA. 4. There was no significant difference between the experimental group that used chitosan membrane only and the control group. But, in combination with bone graft material for space maintanence, periodontal regeneration was improved. Overall, Space maintenance is a critical factor for Guided tissue regeneration using barrier membranes. Also, a barrier membrane itself that has difficulty in maintaining space, achieved better result when used with graft material.

Measurement of soft tissue thickness on posterior palatal area by using computerized tomography in Korean population / 대한치주과학회지

The purpose of this study was to measure the thickness of masticatory mucosa in the hard palate as a donor site for mucogingival surgery by using computerized tomography(CT). Thickness measurements were performed in 84 adult patients who took CT on maxilla for implant surgery and 24 standard measurement points were defined in the hard palate according to the gingival margin and mid palatal suture. Radiographic measurements were utilized after calibration for standardization. Data were analyzed to determine the differences in mucosal thickness by gender, age, tooth positions and depth of palatal vault. The results of this study were as follows: 1. Mean thickness of palatal masticatory mucosa was 3.93+/-0.6mm and females had significantly thinner mean masticatory mucosa(3.76+/-0.56mm) than males(4.04+/-0.6mm)(p0.05). The results suggest that canine and premolar area appears to be the most appropriate donor site for soft tissue grafting procedure. The measurement of the thickness of palatal masticatory mucosa by using computerized tomography can offer useful information clinically but further studies in assessing the validity and reliability of the method using computerized tomography is needed.

Histologic evaluation of macroporous biphasic calcium phosphate(MBCP(R)) and flouorohydrxyapatite(Algipore(R)) in surgically created 1-wall periodontal intrabony defects of minipigs / 대한치주과학회지

Periodontal regenerative therapy and tissue engineering on defects destructed by severe periodontitis need maintaining of space, which provides the environment for cell migration, proliferation and differentiation. Application of bone grafts may offer this environment in periodontal defects. This study evaluated bone graft materials, MBCP(R) and Algipore(R), in surgically created 1-wall periodontal intrabony defects of minipigs by histological analysis. Critical sized(4mmX4mm), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four minipigs. The control group was treated with debridement alone, and experimental group was treated with debridement and MBCP(R) and Algipore(R) application. The healing processes were histologically observed after 8 weeks and the results were as follows. 1. In the control group, limited new bone formation was observed. 2. In MBCP group, more new bone formation was observed compared to other groups. 3. Histologically, dispersed mixture of new bone, biomaterial particles and connective tissue were shown and osteoblasts, osteoclasts and new vessels were present in this area. 4. Defects with Algipore showed limited new bone formation and biomaterial particles capsulated by connective tissue. 5. Histologically, lots of osteoclasts were observed around the biomaterial but relatively small numbers of osteblasts were shown. Within the limitation to this study protocol, MBCP(R) application in 1-wall intrabony defect enhanced new bone formation rather than Algipore(R) application.