Seung Mi Jeong

A 1-year prospective clinical study of soft tissue conditions and marginal bone changes around dental implants after flapless implant surgery.

BACKGROUNDnDespite several reports on the clinical outcomes of flapless implant surgery, limited information exists regarding the clinical conditions after flapless implant surgery.nnnOBJECTIVEnThe objective of this study was to evaluate the soft tissue conditions and marginal bone changes around dental implants 1 year after flapless implant surgery.nnnSTUDY DESIGNnFor the study, 432 implants were placed in 241 patients by using a flapless 1-stage procedure. In these patients, peri-implant soft tissue conditions and radiographic marginal bone changes were evaluated 1 year after surgery.nnnRESULTSnNone of the implants were lost during follow-up, giving a success rate of 100%. The mean probing depth was 2.1 mm (SD 0.7), and the average bleeding on probing index was 0.1 (SD 0.3). The average gingival index score was 0.1 (SD 0.3), and the mean marginal bone loss was 0.3 mm (SD 0.4 mm; range 0.0-1.1 mm). Ten implants exhibited bone loss of >1.0 mm, whereas 125 implants experienced no bone loss at all.nnnCONCLUSIONnThe results of this study demonstrate that flapless implant surgery is a predictable procedure. In addition, it is advantageous for preserving crestal bone and mucosal health surrounding dental implants.

Ridge Alterations following Immediate Implant Placement and the Treatment of Bone Defects with Bio-Oss in an Animal Model

BACKGROUNDnConflicting data exist on the outcome of placing Bio-Oss® (Geitslich Pharm AG, Wolhausen, Switzerland) into extraction sockets. It is therefore relevant to study whether the incorporation of Bio-Oss into extraction sockets would influence bone healing outcome at the extraction sites.nnnPURPOSEnThe aim of this study was to assess peri-implant bone changes when implants were placed in fresh extraction sockets and the remaining defects were filled with Bio-Oss particles in a canine mandible model.nnnMATERIALS AND METHODSnSix mongrel dogs were used in the study. In one jaw quadrant of each animal, the fourth mandibular premolars were extracted with an elevation of the mucoperiosteal flap; implants were then placed in the fresh extraction sockets and the remaining defects were filled with Bio-Oss particles. After 4 months of healing, micro-computed tomography at the implant sites was performed. Osseointegration was calculated as the percent of implant surface in contact with bone. Additionally, bone height was measured in the peri-implant bone.nnnRESULTSnAverage osseointegration was 28.5% (ranged between 14.8 and 34.2%). The mean crestal bone loss was 4.7 ± 2.1 mm on the buccal aspect, 0.4 ± 0.5 mm on the mesial aspect, 0.4 ± 0.3 mm on the distal aspect, and 0.3 ± 0.4 mm on the lingual aspect.nnnCONCLUSIONnThe findings from this study demonstrated that the placement of implants and Bio-Oss® particles into fresh extraction sockets resulted in significant buccal bone loss with low osseointegration.

Comparison of submerged and nonsubmerged implants placed without flap reflection in the canine mandible.

OBJECTIVEnThe purpose of this study was to compare the bone healing around submerged and nonsubmerged implants installed in a canine mandible model using a flapless technique.nnnSTUDY DESIGNnBilateral, edentulated, flat alveolar ridges were created in the mandibles of 6 mongrel dogs. After 3 months of healing, 2 implants were placed in 1 side by either miniflap submerged or flapless nonsubmerged procedures. After healing for an additional 8 weeks, microcomputerized tomography at the implantation site was performed. Osseointegration was calculated as the percent of the implant surface in contact with bone. Bone height was measured in the peri-implant bone.nnnRESULTSnThe mean osseointegration was greater (64.7%) in miniflap submerged sites than in the flapless nonsubmerged sites (56.8%; P < .05). The mean peri-implant bone height was greater (11.0 mm) in the miniflap submerged sites than in the flapless nonsubmerged sites (10.1 mm; P < .05).nnnCONCLUSIONnThis study demonstrated that the submerged procedure was more effective than the nonsubmerged procedure in improving implant anchorage in the early phase after implant placement.

Bone healing around implants following flap and mini-flap surgeries: a radiographic evaluation between stage I and stage II surgery

OBJECTIVEnThe aim of this study was to compare the effects of flap and mini-flap implant surgeries on crestal bone changes around dental implants.nnnSTUDY DESIGNnA total of 286 implants were placed in 129 patients: 142 implants were placed in 58 patients by using a conventional flap procedure, and 144 implants were placed in 71 patients by using a mini-flap procedure. The 2 groups were evaluated radiographically for postoperative changes in the crestal bone level from the time of placement to the time of exposure (3 to 4 months later).nnnRESULTSnThe mean crestal bone loss was 0.26 mm in the flap group and 0.20 mm in the mini-flap group (P > .05). The success rate was 96.5% in the flap group and 100% in the mini-flap group (P < .05).nnnCONCLUSIONnThe results indicate that when implants are placed using a mini-flap procedure, the mini-flap procedure may increase the success rate.

Influence of premature exposure of implants on early crestal bone loss: an experimental study in dogs

OBJECTIVEnSeveral studies have reported on spontaneous early exposure of submerged implants, suggesting that exposed implants have greater bone loss than nonexposed implants. The purpose of this study was to compare the effects of implant-abutment connections and partial implant exposure on crestal bone loss around submerged implants.nnnSTUDY DESIGNnBilateral, edentulated, flat alveolar ridges were created in the mandible of 6 mongrel dogs. After 3 months of healing, 2 fixtures were placed on each side of the mandible following a commonly accepted 2-stage surgical protocol. The fixtures on each side were randomly assigned to 1 of 2 procedures. In the first, a cover screw was connected to the fixture, and the incised gingiva was partially removed to expose the cover screw (partially exposed group). In the second, a healing abutment was connected to the fixture so that the coronal portion of the abutment remained exposed to the oral cavity (abutment-connected group). After 8 weeks, micro-computed tomography (micro-CT) at the implantation site was performed to measure the bone height in the peri-implant bone. Data were analyzed by Wilcoxons signed rank test.nnnRESULTSnThe average bone height was greater for the abutment-connected fixture (9.8 +/- 0.5 mm) than for the partially exposed fixture (9.3 +/- 0.5 mm; P < .05).nnnCONCLUSIONnThese results suggest that when implant exposure is detected, the placement of healing abutments may help limit bone loss around the submerged implants.

Minimally invasive ridge augmentation using xenogenous bone blocks in an atrophied posterior mandible: a clinical and histological study.

Purpose:Although various techniques for the treatment of an atrophic alveolar ridge have been described in the literature, these procedures have increased the morbidity and discomfort for the patient. The purpose of this study was to evaluate histological and clinical results in 9 patients who underwent a subperiosteal tunneling procedure with a Bio-Oss block onlay graft in an atrophic area of the mandible. Patients and Methods:Nine months after grafting, at the time of dental implantation, biopsy samples were taken from the grafted areas of 9 patients and were analyzed histologically. Results:New bone formation through the bovine bone block was observed consistently in the 9 cases. There was direct deposition of bone on the surface of the graft material. Conclusion:The results of this study indicated that ridge augmentation using a subperiosteal tunneling procedure with Bio-Oss bone blocks might be useful for implant placement in the atrophic alveolar ridges.

Vertical ridge augmentation using xenogenous bone blocks: a comparison between the flap and tunneling procedures.

PURPOSEnPrevious studies have shown that the subperiosteal tunneling procedure in vertical ridge augmentation accelerates healing after grafting and prevents graft exposure, with minor postoperative complications. It is conceivable that new bone formation would be greater with the tunneling procedure than with the flap procedure, because the former is minimally invasive. This hypothesis was tested in this study by comparing new bone formation between the flap and tunneling procedures after vertical ridge augmentation using xenogenous bone blocks in a canine mandible model.nnnMATERIALS AND METHODSnTwo Bio-Oss blocks were placed on the edentulous ridge in each side of the mandibles of 6 mongrel dogs. The blocks in each side were randomly assigned to grafting with a flap procedure (flap group) or grafting with a tunneling procedure (tunneling group).nnnRESULTSnThe mean percentage of newly formed bone within the block was 15.3 ± 6.6% in the flap group and 46.6 ± 23.4% in the tunneling group.nnnCONCLUSIONnBased on data presented in this study, when a tunneling procedure is used to place xenogenous bone blocks for vertical ridge augmentation, bone formation in the graft sites is significantly greater than when a flap procedure is used.

Digital intraoral impression technique for edentulous jaws

Few studies have evaluated direct digital scans of edentulous jaws using intraoral scanners because it is difficult to scan edentulous sites that are smooth and devoid of features. A scanning technique is introduced for making direct digital scans of edentulous jaws with intraoral scanners in patients with a broad palate.

Comparison of flap and flapless procedures for the stability of chemically modified SLA titanium implants: an experimental study in a canine model

BACKGROUNDnFlapless implant surgery has been shown to accelerate recovery and increase the vascularity of the peri-implant mucosa after implant placement.nnnOBJECTIVEnThe aim of this study was to compare dental implant stabilization patterns between flap and flapless implant surgeries over the first 8 weeks after implant placement.nnnSTUDY DESIGNnIn 6 mongrel dogs, bilateral, edentulated, and flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants (Straumann SLA-active) were placed in each side of the mandible using either a flap or flapless procedure. The implant stability quotient (ISQ) that was obtained from Osstell Mentor was measured at the time of implantation and weekly over the first 8 weeks after implant placement.nnnRESULTSnImplants stabilized more quickly without flap elevation than with flap elevation. For flapless implants, an increase in stability occurred after 2 weeks without a period of decreasing stability. However, for flap implants, a shift in implant stability from decreasing stability to increasing stability occurred after 2 weeks.nnnCONCLUSIONnIn the canine model, flapless surgical placement of implants may increase the initial stability of implants compared with implants placed after the reflection of the mucoperiosteal flap.

Development of complete dentures based on digital intraoral impressions—Case report

PATIENTnA 60-year-old man presented for refabrication of his maxillary complete denture. In this case, a digital process was chosen to replace the ill-fitted complete maxillary denture. A specialized scan retractor was used to retract the mobile tissues of the lips, cheeks and vestibule while taking a digital impression. The interocclusal record obtained in the patients mouth was scanned in order to digitally register the occlusal vertical dimension. The denture base and teeth were designed on virtual models that were mounted at the occlusal vertical dimension, and were made using CAD/CAM technology.nnnDISCUSSIONnUnlike conventional impression techniques, intraoral scanning is not able to be performed while the tissue is moving. This case report used a scan retractor that facilitated stretching and fixation of the vestibular area. It also helped to retract the lips and cheeks. This report also demonstrates that virtual models at OVD can be obtained without the use of conventional stone models, flasking or processing techniques. One of the main shortcomings in the existing CAD/CAM denture fabrication technology is that it is not able to produce customized denture teeth. The present article demonstrates that the digital denture fabrication workflow can provide customized denture teeth to optimize occlusion.nnnCONCLUSIONnThis case demonstrated how digital complete dentures can be made without requiring conventional stone models or mounting the models in an articulator.