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.
Alveolar Ridge Augmentation ; Animals ; Bicuspid ; Bone Regeneration ; Bone Substitutes ; Collagen ; Dogs ; Durapatite ; Guided Tissue Regeneration ; Inlays ; Maxilla ; Membranes ; Osteogenesis ; Transplants

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.
Checklist ; Dental Implantation ; Educational Measurement ; Mental Competency ; Oral Surgical Procedures

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.
Animals ; Bicuspid ; Collagen ; Dogs ; Guided Tissue Regeneration ; Membranes ; Regeneration ; Root Planing ; Transplants

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.
Animals ; Bone Regeneration ; Calcium ; Calcium Phosphates ; Collagen ; Cyanoacrylates ; Hydroxyapatites ; Membranes ; Osteogenesis ; Porifera ; Rabbits ; Transplants

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.
Animals ; Bicuspid ; Biocompatible Materials ; Bone Substitutes ; Calcium ; Calcium Phosphates ; Collagen ; Dental Cementum ; Dogs ; Freezing ; Glass ; Humans ; Hydrazines ; Hydroxyapatites ; Male ; Membranes ; Osteogenesis ; Regeneration ; Surgical Flaps ; Transplants

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
Consensus ; Dental Implants ; Esthetics, Dental ; Gingiva ; Humans ; Keratins ; Mucous Membrane ; Oral Hygiene ; Periosteum ; Stents ; Suture Techniques ; Sutures

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.
Alveolar Bone Loss ; Animals ; Bicuspid ; Bone Regeneration ; Calcium ; Calcium Phosphates ; Dental Cementum ; Dogs ; Epithelial Attachment ; Jaw ; Regeneration ; Salicylamides

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.
Administration, Oral ; Dentists ; Diphosphonates ; Humans ; Hypogonadism ; Jaw ; Mitochondrial Diseases ; Necrosis ; Neoplasm Metastasis ; Ophthalmoplegia ; Osteitis Deformans ; Osteoclasts ; Osteonecrosis ; Osteoporosis ; Phosphatidylethanolamines ; Risk Assessment

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.
Animals ; Biocompatible Materials ; Bone Regeneration ; Bone Substitutes ; Chitosan ; Dentistry ; Durapatite ; Hand ; Humans ; Hydroxyapatites ; Male ; Membranes ; Nanoparticles ; Orthopedics ; Osteogenesis ; Rats ; Rats, Sprague-Dawley ; Regeneration ; Salicylamides

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.
Dental Implants ; Humans ; Osteoporosis ; Retrospective Studies ; Survival Rate