Carlo Maiorana

Recombinant human bone morphogenetic protein-2 promote and stabilize hard and soft tissue healing for large mandibular new bone reconstruction defects

AbstractNumerous autogenous bone-grafting procedures are available for the recovering of large continuity defects of the mandible. However, these surgical techniques present several limitations involving postoperative morbidity and pain. The development of new bone technique reconstruction not involving autogenous bone graft would offer new opportunities for facial bone reconstruction.This report highlights the possibility of recombinant human bone morphogenetic protein type 2 (rhBMP-2) application without concomitant bone grafting material in the restoration of continuity critical-sized defects after tumor resection in the mandible. The presented case shows a large mandibular reconstruction after tumor removal in a 31-year-old white man affected by ameloblastoma.In this case, the rhBMP-2 application with a carrier consisted on absorbable collagen sponge gives excellent newly formed bone at 18 months of control clinical and radiologic follow-up.The results indicated that the use of rhBMP-2 without concomitant autogenous bone grafting materials in large critical-sized mandibular defects secondary to large mandibular tumor produced excellent regeneration of the treated area.

Randomized controlled trial comparing a variable-thread novel tapered and a standard tapered implant: Interim one-year results

STATEMENT OF PROBLEM A tapered implant with continuously changing threads purported to provide stable tissue support and allow immediate function has been developed. Treatment success and stabilization of supporting tissues over time require documentation. PURPOSE The purpose of this prospective, randomized, controlled, multicenter study was to evaluate changes in bone level and soft tissue behavior between the novel implant (NobelActive/NA) and a standard tapered implant (NobelReplace Tapered Groovy/NR) with regard to immediate function. MATERIAL AND METHODS A total of 177 patients randomly allocated to 3 treatment groups (2 different test implant groups: NA Internal (n=117; internal connection) and External (n=82), and 1 standard treatment group, NR (n=126)) received 325 implants. Implants were placed into healed sites, and all but 6 implants were immediately nonocclusally loaded. Clinical and radiographic evaluations of treatment success, crestal bone levels, and soft tissue changes were performed at the time of placement and after 3, 6, and 12 months. Log-Rank test was used to analyze the differences in survival rate. Marginal bone level was compared using the Kruskal-Wallis test and Mann-Whitney U-test (alpha=.05). RESULTS One-year cumulative survival rates were comparable (96.6% for NA Internal; 96.3% for NA External; 97.6% for NR; P=.852; Log-Rank). Mean (SD) change in bone level was -0.95 mm (1.37) for NA Internal, -0.64 mm (0.97) for NA External, and -0.63 mm (1.18) for NR (P=.589; Kruskal-Wallis). Stable soft tissues and significantly increased papilla scores (P<.001; Wilcoxon signed-rank) were observed for all implant types. CONCLUSIONS The novel implants showed high survival rates as well as stable bone and soft tissue levels after 1 year, and may be recommended for clinical use, even under immediate function.

Use of a Porcine Collagen Matrix as an Alternative to Autogenous Tissue for Grafting Oral Soft Tissue Defects

PURPOSE Soft tissue grafting is often required to correct intraoral mucosal deficiencies. Autogenous grafts have disadvantages including an additional harvest site with its associated pain and morbidity and, sometimes, poor quality and limited amount of the graft. Porcine collagen matrices have the potential to be helpful for grafting of soft tissue defects. PATIENTS AND METHODS Thirty consecutive patients underwent intraoral grafting to re-create missing soft tissue. Defects ranged in size from 50 to 900 mm(2). Porcine collagen matrices were used to reconstruct missing tissue. Indications included preprosthetic (22), followed by tumor removal (5), trauma (2), and release of cheek ankylosis (1). RESULTS The primary efficacy parameters evaluated were the degree of lateral and/or alveolar extension and the evaluation of re-epithelialization and shrinkage of the grafted area. Overall, the percentage of shrinkage of the graft was 14% (range, 5%-20%). The amount of soft tissue extension averaged 3.4 mm (range, 2-10 mm). The secondary efficacy parameters included hemostatic effect, pain evaluation, pain and discomfort, and clinical evaluation of the grafted site. All patients reported minimal pain and swelling associated with the grafted area. No infections were noted. CONCLUSION This porcine collagen matrix provides a biocompatible surgical material as an alternative to an autogenous transplant, thus obviating the need to harvest soft tissue autogenous grafts from other areas of the oral cavity.

Evaluation of the success criteria for zirconia dental implants: a four-year clinical and radiological study.

Objectives. The aim was to evaluate survival and success rates, soft tissue health, and radiographic marginal bone loss (MBL) of zirconia implants placed in the esthetic and posterior areas of the jaws and in association with multiple or single implant restorations after at least 6 months of definitive restoration. Material and Methods. 35 one-piece zirconium implants were utilized for single or partially edentulous ridges rehabilitation. All implants received immediate temporary restorations and six months after surgery were definitively restored. Every 6 months after implant placement, a clinical-radiographic evaluation was performed. For each radiograph, the measurements of MBL were calculated. Results. The results showed that the mean MBL at 48-month followup was 1.631 mm. The mean MBL during the first year of loading was not more significant for implants placed in the first molar regions than for those positioned in other areas. Moreover, no differences in marginal bone level changes were revealed for multiple and single implants, whereas MBL in the first year was observed to be slightly greater for implants placed in the maxilla than for those placed in the mandible. Conclusion. Zirconia showed a good marginal bone preservation that could be correlated with one-piece morphology and characteristics of zirconia implants.

Determinants for success rates of temporary anchorage devices in orthodontics: a meta-analysis (n > 50)

INTRODUCTION The aim of this study was to review the literature and evaluate the failure rates and factors that affect the stability and success of temporary anchorage devices (TADs) used as orthodontic anchorage. METHODS Data were collected from electronic databases: MEDLINE database, Scopus, and Web of Knowledge. Four combinations of term were used as keywords: screw orthodontic failure, screw orthodontic success, implant orthodontic failure, and implant orthodontic success. The following selection criteria were used to select appropriate articles: articles on implants and screws used as orthodontic anchorage, data only from human subjects, studies published in English, studies with more than 50 implants/screws, and both prospective and retrospective clinical studies. RESULTS The search provided 209 abstracts about TADs used as anchorage. After reading and applying the selection criteria, 26 articles were included in the study. The data obtained were divided into two topics: which factors affected TAD success and to what degree and in how many articles they were quoted. Clinical factors were divided into three main groups: patient-related, implant-related, and management-related factors. CONCLUSIONS Although all articles included in this meta-analysis reported success rates of greater than 80 per cent, the factors determining success rates were inconsistent between the studies analysed and this made conclusions difficult.

Histomorphometric Evaluation of Anorganic Bovine Bone Coverage to Reduce Autogenous Grafts Resorption: Preliminary Results

Physiologic resorption due to remodeling processes affects autogenous corticocancellous grafts in the treatment of atrophic jawbone alveolar ridges. Such a situation in the past made overgrafting of the recipient site mandatory to get enough bone support to dental implants in order to perform a prosthetic rehabilitation. Anorganic bovine bone, conventionally used to treat alveolar bone deficiencies in implant surgery, showed a high osteoconductive property thanks to its micro and macrostructure very similar to that of human hydroxyapatite. An original technique provides for the application of a thin layer of anorganic bovine bone granules and a collagen membrane on the top of the corticocancellous onlay bone grafts to reduce in a remarkable way the graft resorption due to remodeling. The results of a clinical prospective study and a histomorphometric analysis done on autogenous grafts harvested from the iliac crest showed that the proposed technique is able to maintain the original bone volume of the corticocancellous blocks.

Maxillary Sinus Elevation With an Alloplastic Material and Implants: 11 Years of Clinical and Radiologic Follow-Up

PURPOSE The aim of this retrospective study was to determine the clinical and radiologic results, over an 11-year period, of resorbable hydroxyapatite used as a bone substitute in maxillary sinus elevation. MATERIALS AND METHODS Between 1996 and 2007, we treated 26 patients with maxillary sinus elevation (27 sinuses) using resorbable hydroxyapatite and simultaneous insertion of 47 titanium implants. Patients were recruited, screened, and accepted or rejected sequentially based on specific inclusion/exclusion criteria. Ten months later, 2-stage surgery and prosthetic rehabilitation were performed. RESULTS During the 11-year follow-up period (mean, 6 years), all the implants appeared clinically and radiologically integrated. The cumulative survival rate was 100%. During the observation period, the resorption of the graft apically to the implant was 1.8 mm on average. CONCLUSION The posterior area of the maxilla often represents a challenging clinical situation because of either the lack of alveolar bone or the structural characteristics of the trabeculae in that specific area. The high survival rate of the implants and the stability of the mineralization of the graft confirmed that resorbable hydroxyapatite was a suitable material for sinus grafting.

Prevention and treatment of postoperative infections after sinus elevation surgery: clinical consensus and recommendations.

Introduction. Maxillary sinus surgery is a reliable and predictable treatment option for the prosthetic rehabilitation of the atrophic maxilla. Nevertheless, these interventions are not riskless of postoperative complications with respect to implant positioning in pristine bone. Aim. The aim of this paper is to report the results of a clinical consensus of experts (periodontists, implantologists, maxillofacial surgeons, ENT, and microbiology specialists) on several clinical questions and to give clinical recommendations on how to prevent, diagnose, and treat postoperative infections. Materials and Methods. A panel of experts in different fields of dentistry and medicine, after having reviewed the available literature on the topic and taking into account their long-standing clinical experience, gave their response to a series of clinical questions and reached a consensus. Results and Conclusion. The incidence of postop infections is relatively low (2%–5.6%). A multidisciplinary approach is advisable. A list of clinical recommendation are given.

Multiple teeth replacement with endosseous one-piece yttrium-stabilized zirconia dental implants.

Objectives: The purpose of this study is to clinically and radiographically evaluate survival and success rate of multiple zirconia dental implants positioned in each patient during a follow-up period of at least 12 months up to 48 months. Study Design: Eight patients were treated for multiple edentulism with 29 zirconia dental implants. All implants received immediate temporary restorations and 6 months after surgery were definitively restored. 6 months to 4 years after implant insertion, a clinical-radiographic evaluation was performed in order to estimate peri-implant tissues health and peri-implant marginal bone loss. Results: Survival rate within follow-up period was therefore 100%. The average marginal bone loss (MBL) from baseline to 6 months was +1.375±0.388 mm; from 6 months to 1 year was +0.22±0.598 mm; from 1 year to 2 years was -0.368±0.387 mm; from 2 years to 3 years was -0.0669±0.425 mm; from 3 years to 4 years +0.048±0.262 mm. The mean marginal bone loss at 4 years from the implants insertion was +1.208 mm. Conclusions: According to several studies, when using a radiographic criterion for implant success, marginal bone loss below 0.9-1.6 mm during the first year in function can be considered acceptable. In our work, radiographic measurements of MBL showed values not exceeding 1.6 mm during the first year of loading and also 1 year up to 4 years after surgery further marginal bone loss was minimal and not significant. This peri-implant bone preservation may be associated to the absence of micro-gap between fixture and abutment since zirconia dental implants are one-piece implant. Moreover, zirconia is characterized by high biocompatibility and it accumulates significantly fewer bacteria than titanium. Key words:Zirconia dental implants, multiple implants, radiographic evaluation, marginal bone loss (MBL).

Clinical and radiographic evaluation of early loaded narrow‐diameter implants: 3 years follow‐up

OBJECTIVE To evaluate the clinical reliability of narrow implants placed in a one-stage procedure and early loaded in the upper and lower incisor region. MATERIAL AND METHODS This is a prospective, single-arm, multicenter study in which patients with missing natural dentition in upper lateral and lower incisor positions were enrolled. Eligible implants (OsseoSpeed™ TX 3.0S, DENTSPLY Implants) were of three different lengths and of 3.0 mm in diameter. One-stage surgery was performed and healing abutment connection took place. Placement of the permanent single crown took place after a 6-10 weeks healing period. Clinical and radiographic checks were performed at implant placement, loading, and at the 6, 12, 24, and 36 months follow-up visits. RESULTS A total of 69 subjects with 97 implants have been included in this study. From surgery to 36 months follow-up, 5.6% of the implants showed bone loss of more than 1 mm, while no bone loss at all were observed for 57.3% of the implants. The mean marginal bone level change from surgery to the 6, 12, and 36 months follow-up visits was -0.27, -0.11, and -0.09 mm, respectively. The total survival rate after 3 years is 95.5%. CONCLUSIONS The data presented show stable marginal bone levels as well as healthy soft tissue around OsseoSpeed™ TX 3.0S implants, after 3 years of function. An interesting finding from this investigation was that a longer healing period before crown placement and loading contributed to statistically significant less marginal bone loss between loading and the 1-year follow-up visit (Galindo-Moreno et al. 2012). This finding, associated with a stable probing pocket depth and a stable crown-gingiva distance, using a one-stage surgical procedure helps to maintain the integrity of the peri-implant soft tissues. Narrow implants can be considered as a valid solution in the treatment of the localized narrow bony defects in the anterior area with reduced spaces between the natural teeth.