Simultaneous placement of an interpositional free gingival graft with nonsubmerged implant placement

PURPOSE: Various surgical techniques target achieving adequate keratinized tissue around dental implants; however, these techniques are usually performed before implant placement or upon the exposure of submerged implants. The aim of this case report is to describe a simultaneous placement of an interpositional free gingival graft (iFGG) with that of nonsubmerged implants in a patient lacking keratinized tissue and to assess the long-term outcome of this grafted gingiva. METHODS: A wedge-shaped free gingnival graft (FGG), including an epithelium-connective tissue (E-C) portion and a connective-tissue-only (CT) portion, was harvested from the palate. The CT portion was inserted under the buccal flap, and the E-C portion was secured tightly around the implants and to the lingual flap. RESULTS: At the 8-year follow-up, the gingival graft remained firmly attached and was well maintained, with no conspicuous shrinkage or reported discomfort during oral hygiene procedures. The use of an iFGG at a nonsubmerged implant placement minimizes the required number of surgical steps and patient discomfort while providing adequate buccal keratinized tissue. CONCLUSIONS: Therefore, the technique could be considered an alternative method in increasing the keratinized tissue for cases that have a minimal amount of keratinized tissue.

Cumulative survival rate of Astra Tech implants: a retrospective analysis

PURPOSE: The aim of this study was to analyze the short-term predictability and reliability of Astra Tech implants according to the demographical distribution of patients and condition of implant sites and location of implants. METHODS: Among patients treated with Astra Tech implant (Astra Tech AB) in the Department of Periodontology at the Dental Hospital of Yonsei University of College of Dentisry and K Dental Clinic from May 2004 to March 2009, 195 implants in 98 patients which had been restored more than 6 months ago were reviewed in this study. Following data were reviewed from patient charts and implants success rate was examined: 1) patient type and implant location, 2) bone status at the implant site, 3) diameter and length of the placed implants, 4) presence or absence of bone augmentation and types of the augmentation. RESULTS: The results from this study are as follows: 1) most implants were placed in the molar area, especially 1st molar area of maxilla, 2) most implants were placed at D2 and D3 bone type, 3) most implants were placed in areas of B and C bone quantity, 4) autogenous and alloplastic bone graft and artificial membrane were used for placement of 74 implants. CONCLUSIONS: Short-term survival rate of Astra Tech implants was 100%.

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.

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.

Bone regeneration capacity of two different macroporous biphasic calcium materials in rabbit calvarial defect / 대한치주과학회지

ABSTRACT PURPOSE: Synthetic bone products such as biphasic calcium phosphate (BCP) are mixtures of hydroxyapatite (HA) and a- tricalcium phosphate (a- TCP). In periodontal therapies and implant treatments, BCP provides to be a good bone reconstructive material since it has a similar chemical composition to biological bone apatites. The purpose of this study was to compare bone regeneration capacity of two commercially available BCP. METHODS: Calvarial defects were prepared in sixteen 9-20 months old New Zealand White male rabbits. BCP with HA and a- TCP (70:30) and BCP with Silicon-substituted hydroxyapatite (Si-HA) and a-TCP (60:40) particles were filled in each defect. Control defects were filled with only blood clots. Animals were sacrificed at 4 and 8 week postoperatively. Histomorphometric analysis was performed. RESULTS: BCP with HAand a- TCP 8 weeks group and BCP with Si-HA and a- TCP 4 and 8 weeks groups showed statistically significant in crease (P<0.05) in augmented area than control group. Newly formed bone area after 4 and 8 weeks was similar among all the groups. Residual materials were slightly more evident in BCP with HA and a- TCP 8 weeks group. CONCLUSIONS: Based on histological results, BCP with HA and a- TCP and BCP with Si-HA and a- TCP appears to demonstrate acceptable space maintaining capacity and elicit significant new bone formation when compared to natural bone healing in 4 and 8 week periods.

Bone formation following dental implant placement with augmentation materials at dehiscence defects in dogs : pilot study / 대한치주과학회지

PURPOSE: Guided bone regeneration(GBR) has emerged as a treatment in the management of osseous defects associated with dental implants. But several studies have reported different degrees of success of guided bone regeneration, depending upon the type of barrier selected, presence or absence of an underlying graft material, types of graft material, feasibility of technique, and clinician's preference. The aim of the present study was to evaluate bone formation following dental implant placement with augmentation materials at dehiscence defects in dogs. MATERIAL AND METHODS: Standardized buccal dehiscence defects(3x5 mm) were surgically 2 Mongrel dog's mandibles, each 8 SLA surface, 8 anodizing surface implants. Each buccal dehiscence defect received flap surgery only(no treatment, control), Cytoflex(R) membrane only, Resolut XT(R) membrane only, Resolut XT(R)+Osteon(TM). Animals were sacrificed at 8 weeks postsurgery and block sections were harvested for histologic analysis. RESULTS: All experimental group resulted in higher bone formation than control. Resolut XT(R)+Osteon(TM) group resulted appeared highest defect resolution. There was no difference between SLA and anodizing surface, nonresorbable and resorbable membrane. CONCLUSION: GBR results in rapid and clinically relevant bone closure on dehiscence defects of the dental implants.