1,721,092 research outputs found
What future in the treatment of severe crestal atrophies: from autologous bone to heterologous bone blocks
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Surgical reconstruction of a maxilla after tumour resection with a heterologous equine bone block created with CAD/CAM procedure: a case report
No full textThis case report describes a successful post-tumour surgical reconstruction of a complete maxilla resection in a 62-year-old man, using an equine bone block [pre-shaped using computer aided design/computer aided manufacturing (CAD/CAM) procedure] as grafting material. Computerised tomographic scans taken 5 months after the reconstructive surgery showed good reconstruction and dimensional augmentation of the lost bone. One year after surgery, the patient showed a great improvement in the emergence profile of the middle part of the face. The use of an equine bone block, pre-shaped using CAD/CAM system, for alveolar ridge reconstruction, seems to be a valuable alternative to autograft. This technique could significantly shorten the actual surgical procedure for the patient and may result in a better fit of the graft than chair-side preparation may allow
Rehabilitation of an atrophic posterior mandible with 4-mm short implants: a 3-year post-loading case report.
No full textAIM: We describe a successful implant-prosthetic rehabilitation of an atrophic posterior mandible with 4 mm long implants.
MATERIAL AND METHODS: The patient refused to undergo any reconstructive surgery and, because the available bone up to the inferior alveolar nerve was only 4.5 and 5 mm, the patient received 4 implants of 4 mm length.
RESULTS: Four months after implant positioning, a temporary prosthesis was put in place which was then replaced by a permanent prosthesis after another four months. The follow-up time is at three years after implants loading.
CONCLUSION: With the limits of this case report the use of such short implants can allow a fixed prosthetic solution without the need for vertically augmenting of the mandibular bone. This procedure considerably reduces intra and postoperative patient discomfort compared to reconstructive surgery for the placing of longer implants
The inlay technique in the treatment of posterior mandibular atrophy.
No full textHorizontal osteotomy with the interposition of bone in the form of a “sandwich”, first described by Schettler (1976), is also known as the “inlay technique” or “interpositional bone grafting”. This technique is indicated for the treatment of vertical atrophy in the posterior mandible. The inlay technique involves raising a coronal osteotomised segment of the mandible that is still attached to the lingual periosteum, and interpositioning a bone block graft between the basal bone and the raised osteotomized segment.
Frequently, however, the interpositional technique is associated with autologous bone harvesting which entails discomfort and postsurgical morbidity. Recently, Felice et al. demonstrated that the use of deproteinised bovine bone mineral (DBBM) blocks in the inlay technique yields clinical and histological results similar to the procedure with autologous bone harvesting from the iliac crest. The DBBM inlay technique is technically more straightforward and much less invasive. Unfortunately, the use of a DBBM block is challenged by the extreme fragility of the block. A high risk of breakage has been reported during DBBM block shaping and placement.
Due to the presence of collagen, a cancellous equine bone block is more rigid and less fragile than the DBBM block; it can be shaped more easily without breaking and so allows a good vertical increase. As a consequence a collagenated bone block could be considered the best solution for the interpositional technique in the posterior mandible
Minimally invasive fixed rehabilitation of a totally edentulous severely atrophic mandible with 4-mm ultrashort immediately loaded implants: A case report
No full textThis case report describes the minimally invasive full fixed rehabilitation of a totally edentulous severely atrophic mandible. The patient refused to undergo any other treatment, from the reconstructive surgery to the removable prosthesis, and asked for a fixed minimally invasive solution in the shortest possible time. Considering that the posterior mandibular bone was inadequate in height and that the interforaminal bone was only 4.3 to 5 mm in height, the patient received four 4-mm-ultrashort implants in the interforaminal area that were immediately loaded. Within all the limitations of this case report this procedure in this specific case appears successful through 2 years of loading
Clinical Classification of Bone Augmentation Procedure Failures in the Atrophic Anterior Maxillae: Esthetic Consequences and Treatment Options
Full text linkAlthough the number of complications and failures in bone augmentation procedures is still relatively high, these problems remain poorly documented. Moreover, the literature concerning reconstructive techniques and the treatment of their complications in the anterior areas rarely considers the final esthetic result. The aim of this paper is to propose a new classification of bone augmentation complications in the esthetic area, providing treatment guidelines useful for the management of these cases. Failures of bony regeneration procedures can be mainly divided into partial failures and complete failures. A partial failure can be solved with a corrective surgical intervention: this second surgery can have success or may not be able to provide the desired esthetic result. When the bone reconstructive procedure fails totally, a complete failure occurs and the whole procedure has to be repeated. This new intervention can have success but also this new reconstructive surgery can fail in the same way as the first, causing important damage and a compromise solution that will hardly be acceptable from an esthetic point of view. Bone augmentation techniques are not completely predictable and are not always able to guarantee the expected result, especially in the atrophic anterior maxilla. Complications and failures can often occur and this possibility must always be clearly explained to those patients with high esthetic demands and expectations
Short implants versus longer implants in vertically augmented posterior mandibles: A randomised controlled trial with 5-year after loading follow-up.
No full textOBJECTIVES: To evaluate whether 6.6-mm long implants could be a suitable alternative to longer implants placed in vertically augmented atrophic posterior mandibles.
MATERIALS AND METHODS: Sixty partially edentulous patients having 7 to 8 mm of residual crestal height and at least 5.5 mm thickness measured on CT scans above the mandibular canal were randomised according to a parallel group design. They were either to receive 1 to 3 submerged 6.6-mm long implants or 9.6 mm or longer implants (30 patients per group) placed in vertically augmented bone. Bone was augmented with interpositional anorganic bovine bone blocks covered by resorbable barriers. Grafts were left to heal for 5 months before implant placement. Four months after provisional acrylic prostheses were delivered, they were replaced, after 4 months, by definitive metal-ceramic prostheses. Outcome measures were: prosthesis and implant failures; complications; and radiographic peri-implant marginal bone level changes. All patients were followed up to 5 years after loading.
RESULTS: Five years after loading, 8 patients dropped out: 3 from the short implant group and 5 from the augmented group. The augmentation procedure failed in 2 patients and only 6.6-mm long implants could be inserted. There were no statistically significant differences for prosthesis and implant failures. Five prostheses failed in 4 patients of the short implant group versus 5 prostheses in 5 patients in the augmented group (Fishers exact test P = 1.0; difference in proportions = 0.07; 95% CI -0.29 to 0.43). Five short implants failed in 3 patients versus 3 long implants in 3 patients (Fishers exact test P = 1.00 difference in proportions = 0.00; 95% CI -0.43 to 0.43). There were statistically more complications in augmented patients (25 complications in 21 augmented patients versus 6 complications in 6 patients of the short implant group) (Fishers exact test P < 0.0001; difference in proportions = 0.60; 95% CI 0.38, 0.82). Both groups gradually lost peri-implant bone in a statistically significant way. Five years after loading, short implant group patients lost an average of 1.49 mm peri-implant bone compared with 2.34 mm in the augmented group. Short implants experienced statistically significantly less bone loss (0.82 mm, 95% CI 0.48; 1.16, P < 0.0001) than long implants.
CONCLUSIONS: When residual bone height over the mandibular canal is between 7 to 8 mm, 6.6 mm short implants could be an interesting alternative to vertical augmentation in posterior atrophic mandibles since the treatment is faster, cheaper and associated with less morbidity. Longer follow-ups may still be needed to confirm these results, however the medium-term prognosis (5 years after loading) of short implants is at least as good as those of longer implants placed vertically in augmented mandibles. Conflict of interest statement: Biomet 3i, manufacturer of the implants used in this investigation, partially supported this trial. However data properties belonged to the authors and by no means did Biomet 3i interfere with the conduct of the trial or the publication of the results
FOUR-MM-LONG VERSUS LONGER IMPLANTS IN AUGMENTED BONE IN ATROPHIC POSTERIOR JAWS: THREE-YEAR POST-LOADING RESULTS FROM A MULTICENTRE RANDOMISED CONTROLLED TRIAL
No full textPURPOSE. To evaluate whether 4-mm-long dental implants could be an alternative to bone augmentation with xenografts and placement of implants of length at least 10 in posterior atrophic jaws. MATERIALS AND METHODS. Forty patients with atrophic posterior (premolar and molar areas) mandibles having 5 to 6 mm bone height above the mandibular canal and 40 patients with atrophic maxillae having 4 to 5 mm bone height below the maxillary sinus were randomised according to a parallel-group design to receive one to three 4.0-mm-long implants or one to three implants of length at least 10 mm in augmented bone at two centres. All implants had a diameter of 4.0 or 4.5 mm. Mandibles were vertically augmented with interpositional equine bone blocks and resorbable barriers. Implants were placed 4 months after grafting. Maxillary sinuses were augmented with particulated porcine bone via a lateral window covered with resorbable barriers, and implants were placed simulta-neously. Implants were not submerged. Four months later, screw-retained reinforced acrylic restorations were fitted, and replaced after 4 months by definitive screw-retained metal-composite prostheses. Patients were followed up to 3 years post-loading. Outcome measures were: prosthesis and implant failures, any complications, and peri-implant marginal bone level changes. RESULTS. Nine patients dropped out, six from the augmentation group and three from the short implant group. In six augmented mandibles (30%) it was not possible to place implants of length at least 10.0 mm, so shorter implants had to be placed instead. In man-dibles, two implants from the augmentation group failed in two patients, versus two 4.0-mm-long implants in two patients from the short implant group. In maxillae, four short implants failed in three patients versus seven long implants in four patients (two long implants and one short implant dropped into the maxillary sinus). Three prostheses on short implants (one mandibular and two maxillary) failed or were placed at a later stage due to implant failure, versus eight prostheses (three mandibular and five maxil-lary) at augmented sites. There were no statistically significant differences in implant failures (P [Fisher’s exact test] = 0.159; difference in proportion = 0.05; CI 95%-0.11 to 0.21) or prostheses failures (P [Fisher’s exact test] = 0.919; difference in proportion = 0.02; CI 95%-0.14 to 0.18). There were more patients affected by complications in the augmentation group (18 patients affected by 30 complications versus 8 patients affected by 10 complications), but the difference was not statistically significant (P [Fisher’s exact test] = 0.587; difference in proportion =-0.72; CI 95%-0.29 to 0.14). At 3 years post-loading, average peri-implant bone loss was 0.62 mm at 4-mm-long mandibular implants, 0.71 mm at 10-mm or longer mandibular implants, 1.14 mm at short maxillary implants and 0.73 mm at long maxillary implants. The difference was not statistically significant in mandibles (mean difference-0.08 mm, 95% CI-0.37 to 0.20, P [ANCOVA] = 0.568), but was significant in maxillae, with greater bone loss at short implants (mean difference 0.41 mm, 95% CI-0.04 to 0.87, P [ANCOVA] = 0.037). CONCLUSIONS. Three years after loading, 4.0-mm-long implants yielded similar, if not bet-ter, results than longer implants in augmented jaws, but were affected by fewer compli-cations. Hence, short implants may be preferable to bone augmentation, especially in mandibles, since the treatment is less invasive, faster, cheaper, and associated with less morbidity. However, 5-to 10-year post-loading data will be necessary to make reliable recommendations
Case of severe bone atrophy of the posterior maxilla rehabilitated with blocks of equine origin bone: Histological Results.
No full textPURPOSE: To report the histological outcomes of a case of bilateral severely resorbed posterior maxilla augmented with the use of blocks of enzymatically deantigenated equine bone.
MATERIALS AND METHODS: In conjunction with bilateral sinus lifts, blocks of enzymatically deantigenated equine bone were used bilaterally to augment the severely atrophic maxilla of a patient seeking a fixed implant-supported prosthesis. After 8 months, bone core samples were obtained from the augmentation sites and implants were placed.
RESULTS: Six months after implant placement, the peri-implant bone levels were maintained. A prosthesis delivered 3 months after implant placement provided excellent rehabilitation. Histological analysis of the bone cores revealed that the graft material was still undergoing remodeling, with newly formed vital bone in all fields and osteoclasts included in the mineralized component.
CONCLUSIONS: The deantigenated equine bone was biocompatible and resorbed only minimally. This material seems to offer excellent potential for being incorporated in a procedure that increases the width of edentulous alveolar crests
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