Immediate placement in extraction sites followed by immediate loading: a pilot study and case presentation

The purpose of the study was to compare the results of implants immediately loaded in edentulous sites with implants loaded immediately in extraction sites. Since December 1998, we selected a small group of patients for immediate or early loading. Seventy-five implants were placed in nine jaws of seven patients. Two of the patients received implants in both the maxilla and mandible. Of the 75 implants placed, 29 were placed in immediate extraction sites. Twenty-six of the 29 that were placed in immediate extraction sites were loaded in less than 3 weeks. Of the 75 implants placed, 62 were loaded early (less than 3 weeks). Two implants have been lost. The remaining 13 implants were buried and allowed to heal in the customary manner. None of the buried implants failed. One of the implants lost was in an extraction site and one was in a nonextraction site. Of the 33 implants that were placed in edentulous areas and immediately loaded, one was lost. This is compared with the 29 implants placed in extraction sites that were immediately loaded. We conclude that the success rates for implants immediately loaded in extraction sites and edentulous sites are comparable.     

Evaluation of a new polytetrafluoroethylene guided tissue regeneration membrane in healing extraction sites

The biological principles underlying guided tissue regeneration (GTR) are apparently well understood, and many of the molecular events involved in bone regeneration are being investigated. Much controversy exists, however, as to which membrane biomaterial is ideal for use in these procedures. Adding to the confusion, new applications of GTR membranes continue to evolve, such as extraction site reconstruction, implant site development, ridge augmentation, and the use of membranes in conjunction with the placement of dental implants. These innovative techniques place demands on the membrane that were unforeseen when the first generation of devices was developed. The present study suggests that the ideal design characteristics of a barrier membrane, such as pore size and polymer type, may depend on the intended use of the membrane, and are not fixed criteria that should be applied to all membrane devices. This article describes the clinical results in a series of case studies using a high-density, microporous polytetrafluoroethylene membrane (Cytoplast Regentex GBR-200a). To evaluate the clinical efficacy of this membrane and technique, clinical and histological evaluation of the regenerated tissue are presented.     

Osseous choristoma of buccal mucosa: report of a case

A rare case of osseous choristoma is presented. The lesion, in a 12-year-old girl, involved cheek mucosa and was successfully treated by local excision.     

Osseous resective surgery: long-term case report

This case report evaluated the long-term effects of osseous resective therapy in the treatment of a patient with moderately advanced periodontal disease. In 1984, the patient underwent initial therapy followed by a periodontal surgical phase consisting of osseous recontouring with an apically positioned flap. After 20 years, in 2003, the patient presented with a traumatic complication. An exploratory surgery revealed a fracture on the roof of the pulp chamber on the maxillary left first molar. The buccal roots were resected, preserving the palatal root, and a reevaluation of the long-term outcome of osseous resective surgery was performed. It is suggested that the positive treatment result is the consequence of the reestablishment of tissue morphology favorable for oral hygiene and plaque control by the patient.     

Bone regeneration around titanium dental implants in dehisced defect sites: a clinical study.

Insufficient bone volume can be a significant problem when placing dental implants. This clinical study was designed to evaluate bone regeneration potential at dehisced dental implant sites. Nineteen titanium dental implants with exposed threads were studied. To create a secluded space for bone formation, an expanded polytetrafluoroethylene (e-PTFE) membrane was placed over the exposed implant sites secured with an implant cover screw and completely covered with the flap. Three membranes perforated the overlying soft tissue during the healing time and were removed prematurely. The remaining membranes were removed after an uneventful healing period of 4.5 to 6 months. Fourteen of 19 dehisced implant sites were completely covered with newly formed bonelike tissue; 4 implants demonstrated partial bone fill at reentry and 1 implant showed partial fill with soft tissue. In five implant sites a reentry was performed between 6 and 9 weeks; nonmineralized fibrous tissue was found to fill the space under the membrane. At 16 of the 19 implant sites there were similar dehiscence-type defects that were evaluated as a group. These dehiscences varied from 2.0 to 9.0 mm. The percentage of bone fill at reentry ranged from 28.4% to 100% (mean 89.6%; SD 22.51; SE 5.63) and was highly significant (P < .0001). Six to 12 months after prosthesis connection, 12 of the 19 implants were available for radiographic interpretation and an average bone loss of 1.73 mm (SD = 0.43) was measured. This surgical application of an e-PTFE membrane suggested a viable clinical method for enhancing bone formation around dental implants.     

Guided tissue regeneration for implants placed into extraction sockets: a study in dogs.

Twelve 10 mm implants were placed into immediate extraction sockets in dogs. Six implants were isolated with PTFE membranes and 6 sites served as controls. Standardized clinical measurements were taken at test and control sites. At 18 weeks the dogs were anesthetized and flaps were laid for the purpose of obtaining clinical measurements. The average gain of bone around augmented implants was 2.6 mm, while control sites had an average bone gain of 1.0 mm. Ridge width adjacent to augmented sites increased by 1.2 mm and control sites had an increased width of 0.6 mm. Histologic evaluation of test and control specimens showed greater bone formation around augmented implants. Implants augmented with PTFE membranes had clinically significant amounts of bone regeneration when compared with controls.     

Guided tissue regeneration around dental implants in immediate and recent extraction sites: initial observations.

Guided tissue regeneration, the principle of using membranes to exclude epithelial tissue during wound healing, thus enhancing periodontal regeneration, is an exciting addition to the implant armamentarium. However, additional clinical review of the results, advantages, and disadvantages of guided tissue regeneration is necessary before the procedure can be recommended for routine use. To this end, the author reports three representative cases in which membranes were used to encourage healing and discusses the results and problems.     

Immediate placement of multiple mini dental implants into fresh extraction sites: a case report

This case report discusses the immediate placement of 3 mini dental implants into 3 fresh extraction sockets. The implants were used to support a splinted fixed partial denture. Immediately placing implants of a very small diameter into fresh extraction sockets to support a fixed partial denture is possible. Some implant sites cannot accept standard-sized implants because of length or width deficiencies. Very small diameter implants may be able to support fixed prostheses in these sites.     

Aesthetic restoration of the compromised root: a case report.

The amount of tooth structure that remains after endodontic therapy and post preparation is of prime importance as the strength and resistance to root fracture of an endodontically treated tooth is directly related to the amount of residual dentine. The desired post diameter is determined by tooth morphology and the endodontic procedures (for root canal debridement) with the aim being to avoid removing too much tooth structure. Increasing the diameter of the post does not provide a significant increase in the retention of the post; it only increases the stiffness of the post at the expense of the remaining dentine and the fracture resistance of the root. There is little indication for increasing the post width beyond the endodontic cleaning and shaping procedures for all post systems. The post diameter needs to be controlled to preserve the radicular dentine, reduce the potential for perforations, and permit the tooth to resist fracture. However, endodontic treatment often involves wide flared canals where cast posts are the standard method of treatment. These thin-walled canals are then further compromised by the placement of a tapered cast post--thus increasing its risk for fracturing. The Luminex light, transmitting posts provide an alternative treatment option by strengthening weakened, endodontically treated teeth by the combined bonding action of dentine bonding agents and composite resin restorative material. The paper reports on a case where a wide flared root canal was rehabilitated with composite resin using a light-transmitting post.     

Connective tissue growth factor expressed in rat alveolar bone regeneration sites after tooth extraction

OBJECTIVE: To understand bone regeneration process after tooth extraction could be a clue to develop a new strategy for alveolar bone reconstruction. Recently, accumulated evidences support that connective tissue growth factor (CTGF) is implicated in tissue repair of many tissues. In this study, we investigated the spatial and temporal expression of CTGF in the rat tooth extraction sockets. DESIGN: Five weeks old wild type male rats (weighing 120 g) were used for this experiment. Expression of CTGF was determined by immunohistochemistry and in situ hybridization in the rat upper molar tooth extraction sockets at 2, 4, 7, 10 and 14 days after tooth extraction. RESULTS: CTGF was expressed strongly in the endothelial cells migrating into the granulation tissue at the bottom of the sockets during 4 days after tooth extraction. During the reparative process, no apparent chondrocyte-like cell appeared in the sockets, while osteoblast-like cells proliferated in the sockets with low CTGF expression at 7, 10, 14 days after extraction. As expected, no staining was observed with the preimmune rabbit IgG and CTGF sense probe. CTGF may play an important role in angiogenesis and granulation tissue formation specifically at early healing stage after tooth extraction to initiate alveolar bone repair. CONCLUSION: CTGF was expressed at early healing stage of the rat tooth extraction wound.     

A radiographic study of roots in extraction sites.

1) Roots that are overparalleled to the extent that the apices touch do not relapse to the desired upright positions. 2) Roots that are overparalleled, but the apices do not touch, tend to upright but, in so doing, leave space between the crowns. 3) Roots that are underparalleled at the completion of active treatment tend to maintain their positions or diverge even farther. 4) The best postretention results were cases in which roots and crowns were positioned in normal, upright parallel positions. Slight spaced remaining in these situations appeared to close evenly.     

Osseous regeneration in the presence of four common hemostatic agents.

The iliac crest is a common site for bone procurement in oral and maxillofacial surgery. The goal of this study was to evaluate the potential for bone regeneration in the presence of four common hemostatic agents in a manner that parallels iliac bone procurement in humans. The agents evaluated were 1) Avitene (microfibrillar collagen; Medchem Products, Inc, Woburn, MA); 2) bone wax (beeswax with isopropyl palmitate; Ethicon, Inc, Somerville, NJ); 3) Gelfoam (absorbable gelatin sponge; The Upjohn Company, Kalamazoo, MI); and 4) Surgicel (oxidized regenerated cellulose; Johnson & Johnson Products, Inc, Patient Care Division, New Brunswick, NJ). Five surgical defects in each of four dogs were created for placement of the four materials; one defect served as an empty control site. The dogs were then allowed to heal over a 2-month period. Radiographic and histologic examination showed new bone formation in the presence of Avitene, Surgicel, and Gelfoam. Residual material incorporated in bone, without foreign-body response, was noted in the Avitene and Gelfoam sites. Bone wax, however, showed an intense foreign-body reaction, characterized by giant cells, plasma cells, fibrous granulation tissue, and lack of bone reformation. On the basis of these initial findings, it was concluded that Surgicel, Avitene, and Gelfoam may be adequate hemostatic agents for use in iliac bone procurement, whereas the use of bone wax appears to be contraindicated.     

Immediate transmucosal implant placement in molar extraction sites: a 12-month prospective multicenter cohort study

Aim: To assess the clinical and radiographic outcomes of immediate transmucosal placement of implants into molar extraction sockets. Study design: Twelve‐month multicenter prospective cohort study. Material and methods: Following molar extraction, tapered implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were immediately placed into the sockets. Molars with evidence of acute periapical pathology were excluded. After implant placement and achievement of primary stability, flaps were repositioned and sutured allowing a non‐submerged, transmucosal healing. Peri‐implant marginal defects were treated according to the principles of guided bone regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresrobable collagen membrane. Standardized radiographs were obtained at baseline and 12 months thereafter. Changes in depth and width of the distance from the implant shoulder (IS) and from the alveolar crest (AC) to the bottom of the defect (BD) were assessed. Results: Eighty‐two patients (42 males and 40 females) were enrolled and followed for 12 months. They contributed with 82 tapered implants. Extraction sites displayed sufficient residual bone volume to allow primary stability of all implants. Sixty‐four percent of the implants were placed in the areas of 36 and 46. GBR was used in conjunction with the placement of all implants. No post‐surgical complications were observed. All implants healed uneventfully yielding a survival rate of 100% and healthy soft tissue conditions after 12 months. Radiographically, statistically significant changes (P<0.0001) in mesial and distal crestal bone levels were observed from baseline to the 12‐month follow‐up. Conclusions: The findings of this 12‐month prospective cohort study showed that immediate transmucosal implant placement represented a predictable treatment option for the replacement of mandibular and maxillary molars lost due to reasons other than periodontitis including vertical root fractures, endodontic failures and caries.     

Conditions for success in guided bone regeneration: retrospective study on 376 implant sites

BACKGROUND: Used alone or in association with bone, guided bone regeneration is a clinically accepted method to increase the volume of bone during implant placement. Concerns about appropriate surgical techniques and the predictability of the results questions still exist. The aim of this study was to assess the conditions for success. METHODS: Three-hundred-seventy-six implants were placed in association with 214 non-resorbable membranes. In 109 implants, the membrane was secured on a blood clot; for 213 implants, membrane was placed with autogenous bone; and for 54 implants it was placed with allogenic bone. The surgical procedure, the primary closure, the timing of re-entry, and the density of regenerated tissue were studied. RESULTS: In 19 membranes, barrier exposure occurred before 3 months in these instances, the regenerated tissue was removed; another 7 membranes were exposed between 3 and 6 months. The 188 non-exposed membranes were removed between 6 and 12 months. In cases of exposure before 3 months, the regenerated tissue was soft and then removed. After closure for 6 months or more, the regenerated tissue was dense and resistant to probe pressure. The best results were obtained when the membranes were placed with autogenous bone. CONCLUSIONS: If all the clinical steps are appropriately followed, guided bone regeneration using an autogenous bone graft and implant placement is a predictable technique for increasing bone volume.