Prognosis of Deantigenated Equine Bone Used for Bone Augmentation: A Multicenter Retrospective Study on Early and Late Postsurgical Complications in 81 Consecutive Patients.

PURPOSE: To evaluate the clinical outcome of deantigenated equine bone (DEB) grafts in a series of patients treated with DEB at six months postaugmentation. MATERIALS AND METHODS: One hundred DEB grafts were inserted in 81 patients between January 2004 and December 2006. Thirty-two DEBs were blocks and 68 were granules (52 sinus lift and 16 guided bone regeneration [GBR] procedures performed). A total of 147 implants were inserted. A Pearson chi-square test was used to detect any statistically significant correlation between the studied variables and early and/or late failures. RESULTS: There were 6 early and 26 late graft failures and another 16 failures after prosthesis placement. The overall failure rate was 25% in the GBR procedures, 31.9% in sinus lift, and 54.3% with blocks, for a total complication rate of 39.5%. A statistically significant relation was detected with respect to graft type and early complications (p = .005), with a worse outcome for DEB blocks compared to granules. After provisional prosthesis restoration, 23 implants were lost, and another 41 failed after definitive prosthesis delivery, for an overall failure rate of 43.5%. The follow-up period was 3 years after surgery. CONCLUSIONS: DEB grafting material had a very high rate of complications. Blocks had more than 50% failures, mainly in the immediate postoperative period. Other procedures such as GBR and sinus lift also showed more than 25% infections and resorption, and late failures (i.e., after-implant placement) were also common. Our results show that DEB is less than ideal for crestal bone reconstruction.

Immediate loading of post-extractive versus delayed placed single implants in the anterior maxilla: outcome of a pragmatic multicenter randomised controlled trial 1-year after loading.

PURPOSE: To compare the effectiveness of immediate post-extractive single implants with delayed implants, placed in preserved sockets after 4 months of healing. Implants that achieved an insertion torque of at least 35 Ncm were immediately non-occlusally loaded. MATERIALS AND METHODS: Just after tooth extraction, and in the presence of less than 4 mm of vertical loss of the buccal bone in relation to the palatal wall, 106 patients requiring a single immediate post-extractive implant in the maxilla from second to second premolar were randomly allocated to immediate implant placement (immediate group; 54 patients) or to socket preservation using anorganic bovine bone covered by a resorbable collagen barrier (delayed group; 52 patients), according to a parallel group design at three different centres. Bone-to-implant gaps were to be filled with anorganic bovine bone, however this was not carried out in 17 patients (corresponding to 40% of those who should have been grafted). Four months after socket preservation, delayed implants were placed. Implants inserted with an insertion torque of at least 35 Ncm were immediately loaded with non-occluding provisional single crowns, then replaced after 4 months by definitive crowns. Patients were followed up to 1 year after loading. Outcome measures were implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes and patient satisfaction recorded by blinded assessors. RESULTS: Nineteen (35%) implants were not immediately loaded in the immediate group versus 39 (75%) implants in the delayed placement group because an insertion torque superior to 35 Ncm could not be obtained. Six patients dropped out 4 months after loading from the delayed group versus none in the immediate group. Two implants failed in the immediate group (6%) versus none in the delayed group, with the difference showing no statistical significance (difference in proportions = 0.04; 95% CI: -0.03 to 0.11; P = 0.187). Eight minor complications occurred in the immediate group and one in the delayed group, and this was statistically significant (difference in proportions = 0.13; 95% CI: 0.03 to 0.23; P = 0.028). At delivery of definitive crowns, 4 months after loading, the mean aesthetic score was 12.8 and 12.6 in the immediate and delayed groups, respectively. At 1 year after loading, the mean aesthetic score was 13.0 and 12.8 in the immediate and delayed groups, respectively. There was no statistically significant difference at 4 months (P = 0.500) and at 1 year (P = 0.615). Marginal bone levels at implant insertion (after bone grafting) were 0.10 mm for immediate implants and 0.02 mm for delayed implants, which did not have a statistically significantly difference (mean difference = 0.08; 95% CI: 0.04 to 0.12; P < 0.001). One year after loading, patients of the immediate group lost on average 0.23 mm and those in the delayed group lost 0.29 mm, the difference being statistically significant (mean difference = -0.06; 95% CI: -0.11 to -0.01; P = 0.036). Patients of both groups were equally satisfied at 4 months as well as at 1 year after loading. CONCLUSIONS: There are more complications with immediate post-extractive implants in comparison to delayed implants. It seems more difficult to obtain an implant insertion torque superior to 35 Ncm in sockets preserved with anorganic bovine bone after a 4-month healing period than with postextractive sites. The aesthetic outcome appears to be similar for both groups.

Posterior atrophic mandible rehabilitation with onlay allograft created with CAD-CAM procedure: a case report.

AIM: Implant rehabilitation of the atrophic right posterior mandible in a 48-year-old woman using dehydrated homologous bone block, shaped with a computer aided design-computer aided manufacturing (CAD-CAM) system, to avoid harvesting of autologous bone block and to assure a perfect fitting of the block above the alveolar crest. RESULTS: After 7 months, 6.09, 7.36, and 8.08 mm (mean, 7.18 mm) of total horizontal bone gain was observed at sites 6, 12, and 18 mm posterior to the right mental foramen, respectively. CONCLUSIONS: The use of a bone block with CAD-CAM system for alveolar ridge augmentation is a valuable alternative to autograft because it reduces time, cost, and complications for the patients. Data from a computerized tomographic scan can be used to shape a precise 3-dimensional homologous bone block using a CAD-CAM system.

Ridge augmentation with mineralized block allografts: clinical and histological evaluation of 8 cases treated with the 3-dimensional block technique.

PURPOSE: Bone augmentation is frequently used to create sufficient bone volume for ideal implant placement. Severely resorbed ridges require extensive bone augmentation in the form of block allografts. A 3-dimensional graft technique has been developed to augment atrophic areas. This technique involves modifying the graft on a sterile prototype of the recipient site before the surgery. This article investigates the clinical and histological outcomes of ridge augmentation using this technique. MATERIALS AND METHODS: Eight partially edentulous patients were recruited. Ridge augmentations were performed using block allografts, preadjusted, based on sterile prototypes of the recipient bed before the surgeries. After 8 months, 20 implants were inserted into the grafted sites. Eight bone cores were harvested for histological analysis. RESULT: Highly vital and mineralized bone with lamellar organization was observed at the grafted sites. CONCLUSION: Having the ability to modify the allogeneic block grafts to fit the recipient sites before the surgery minimized the surgical time and risk of postoperative complications such as infection. In addition, the clinician could concentrate fully on achieving tension-free primary wound closure.

Immediate non-occlusal loading of immediate post-extractive versus delayed placement of single implants in preserved sockets of the anterior maxilla: 4-month post-loading results from a pragmatic multicentre randomised controlled trial.

PURPOSE: To compare the effectiveness of immediate post-extractive single implants with delayed implants placed in preserved sockets after 4 months of healing. Implants that achieved an insertion torque of at least 35 Ncm were immediately non-occlusally loaded. MATERIALS AND METHODS: Just after tooth extraction and in the presence of a loss of the buccal plate bone less than 4 mm, compared to the palatal wall, 106 patients requiring a single immediate postextractive implant in the maxilla from second premolar to second premolar were randomly allocated to immediate implant placement (immediate group; 54 patients) or to socket preservation using anorganic bovine bone covered by a resorbable collagen barrier (delayed group; 52 patients) according to a parallel group design at three different centres. Bone-to-implant gaps were to be filled with anorganic bovine bone, however this was not done in 17 patients (corresponding to 40% of those who should have been grafted). Four months after socket preservation, delayed implants were placed. Implants placed with an insertion torque >35 Ncm were immediately loaded with non-occluding provisional single crowns, replaced, after 4 months, by definitive crowns. Outcome measures were implant failures, complications, aesthetics assessed using the pink esthetic score (PES), and patient satisfaction, recorded by blinded assessors. All patients were followed up to 4 months after loading. RESULTS: Nineteen (35%) implants were not immediately loaded in the immediate group versus 39 (75%) implants in the delayed placement group because an insertion torque >35 Ncm could not be obtained. No patient dropped out. Two implants failed in the immediate group (4%) versus none in the delayed group. More minor complications occurred in the immediate group (8) than the in the delayed group (1) and this was statistically significant (P = 0.032). At delivery of definitive crowns, 4 months after loading, aesthetics were scored as 12.8 and 12.6 in the immediate and delayed groups, respectively. There was no statistically significant difference (P = 0.5). Patients of both groups were equally satisfied. CONCLUSIONS: There were more complications at immediate post-extractive implants when compared to delayed implants. The aesthetic outcome appears to be similar for both groups and it seems more difficult to obtain a high insertion torque in sockets preserved with anorganic bovine bone.

Simplified onlay grafting with a 3-dimensional block technique: a technical note.

Block allografts can serve as effective alternatives to block autografts but are more brittle and can easily break if not properly contoured to fit the defect site. The need to make such preparations during surgery can prolong the invasive procedure and may result in a less-than-optimum graft preparation that can compromise success. The sterile 3D block technique allows block allografts to be prepared and attached to a stereolithography model of the patient's jaw prior to surgery and then stored in a sterile environment until surgical delivery.