Semaan Abi Najm

Bisphosphonate-associated osteonecrosis of the jaw: A key role of inflammation?

Osteonecrosis of the jaw (ONJ) can be associated with nitrogen-containing bisphosphonates (NBPs) therapy. Various mechanisms of NBP-associated ONJ have been proposed and there is currently no consensus of the underlying pathogenesis. The detailed medical and dental histories of 30 ONJ patients treated with NBPs for malignant diseases (24) or osteoporosis (6) were analyzed. The necrotic bone was resected and analyzed histologically after demineralization. In 10 patients the perinecrotic bone was also resected and processed without demineralization. Alveolar bone samples from 5 healthy patients were used as controls. In 14 ONJ patients, serial technetium-99m-methylene diphosphonate scintigraphic scans were also available and confronted to the other data. Strong radionuclide uptake was detected in some patients several months before clinical diagnosis of ONJ. The medullary spaces of the necrotic bone were filled with bacterial aggregates. In the perinecrotic bone, the bacteria-free bone marrow characteristically showed an inflammatory reaction. The number of medullary inflammatory cells taken as an index of inflammation allowed us to discriminate two inflammation grades in the ONJ samples. Low-grade inflammation, characterized by marrow fibrosis and low inflammatory cells infiltration, increased numbers of TRAP(+) mono- and multineacleated cells was seen in patients with bone exposure<2 cm(2). High-grade inflammation, associated with larger lesions, showed amounts of tartrate-resistant acid phosphatase(+)/calcitonin receptor(-) mono- and multinucleated cells, osteocyte apoptosis, hypervascularization and high inflammatory cell infiltration. The clinical extent of ONJ was statistically linked to the numbers of inflammatory cell. Taken together these data suggest that bone necrosis precedes clinical onset and is an inflammation-associated process. We hypothesize that from an initial focus, bone damage spreads centrifugally, both deeper into the jaw and towards the mucosa before the oral bone exposure and the clinical diagnosis of ONJ.

Osteotome Sinus Floor Elevation without Grafting: A 10-Year Prospective Study

BACKGROUND Little is known about the long-term outcome of implants placed in the atrophic maxilla using osteotome sinus floor elevation (OSFE) without grafting. PURPOSE The study aims to evaluate the long-term efficiency of the procedure and stability of the peri-implant bone formed following implant placement without grafting into resorbed posterior maxilla. MATERIALS AND METHODS Twenty-five implants (≤10 mm in length) were placed in 17 patients using OSFE without grafting. The mean residual bone height was 5.4 ± 2.3 mm. Bone levels were evaluated at 1, 3, 5, and 10 years using periapical radiographs. RESULTS Fifteen patients (23 implants) participated in the 10-year examination. All implants fulfilled the survival criteria. Following surgery, the implant sites gained endo-sinus bone (mean: 3.0 ± 1.4 mm). The mean crestal bone loss (CBL) was limited to 1.0 ± 0.9 mm. The difference in mean endo-sinus bone gain and CBL was statistically significant between 1 and 10 years, but not between 3 and 5, 3 and 10, and 5 and 10 years. CONCLUSIONS At 10 years, the implant survival rate was 100%. Endo-sinus bone was mainly gained during the first year. This study demonstrates the long-term predictability of OSFE without grafting and simultaneous implant placement.

Potential adverse events of endosseous dental implants penetrating the maxillary sinus: long-term clinical evaluation.

The aim of this study was to evaluate the nature and incidence of long‐term maxillary sinus adverse events related to endosseous implant placement with protrusion into the maxillary sinus.

A 5‐ to 6‐year radiological evaluation of titanium plasma sprayed/sandblasted and acid‐etched implants: results from private practice

OBJECTIVES This study aimed to determine bone level changes after 5-6 years of follow-up for a large group of one-stage dental implants consecutively placed in private practice. Potential confounding factors influencing crestal bone loss (CBL) were also assessed. MATERIALS AND METHODS A total of 378 transmucosal Straumann implants in 174 patients were examined radiographically. Half of the study population (189 implants) had a titanium plasma sprayed (TPS) surface, and the other half (189 implants) were sandblasted and acid-etched (SLA). Mean CBL was measured from 5 to 6 years post-operative radiographs on the basis of known implant landmarks. Correlations of increased CBL with various independent variables were also investigated. Statistical analyses were performed using generalized estimating equations. RESULTS Radiographic measurements showed a CBL ≤ 1.5 mm for 65% of studied implants. A CBL > 1.5 mm was found for 28% of implants, while 7% of implants had a CBL ≥ 3 mm. Three factors significantly influenced CBL (P < 0.05): implant surface texture (TPS > SLA), smoking status (smokers > non-smokers), and implant location (anterior > posterior). CONCLUSIONS CBL was ≤1.5 mm after 5-6 years for the majority of followed implants. For implants with a CBL > 1.5 mm, statistically significant correlations were found for TPS surface type, anterior jaw locations, and smoking. Implant length did not influence CBL.

Graft shrinkage and survival rate of implants after sinus floor elevation using a nanocrystalline hydroxyapatite embedded in silica gel matrix: a 1-year prospective study.

Objectives:The aims of this study were (1) to evaluate the vertical shrinkage percentage of nanocrystalline hydroxyapatite embedded in silica gel used for maxillary sinus floor elevation (SFE) and (2) to determine the survival rate of the implants 1 year after placement in the healed grafted sinuses. Materials and Methods:Eleven maxillary sinuses were augmented in eight patients with NanoBone. After a healing period averaging 14.42 months, 19 implants were placed and followed up with clinical and radiographic evaluation. Panoramic radiographs were taken immediately after SFE and at 12 months after grafting. Measurements of changes in height were made by a computerized measuring technique using an image editing software. Results:The mean graft height shrinkage percentage at 12 months after surgery was 8.84% (±5.32). One implant was lost before loading. All the 18 remaining osseointegrated implants received the prosthetic rehabilitation and were controlled after 3 months of functional loading. The implant survival rate at the 1-year interval was 94.74%. Conclusions:A 100% NanoBone alloplastic graft used in lateral SFE procedures presented limited height shrinkage. Implants placed in these grafted sinuses showed survival rates similar to those found in published data. These results should be interpreted cautiously considering the studys reduced sample size.

Paradigm Shift in the Management of the Atrophic Posterior Maxilla

When the posterior maxilla is atrophic, the reference standard of care would be to perform sinus augmentation with an autologous bone graft through the lateral approach and delayed implant placement. However, placement of short implants with the osteotome sinus floor elevation technique and without graft can be proposed for an efficient treatment of clinical cases with a maxillary residual bone height of 4 to 8 mm. The use of grafting material is recommended only when the residual bone height is ≤4 mm. Indications of the lateral sinus floor elevation are limited to cases with a residual bone height ≤ 2 mm and fused corticals, uncompleted healing of the edentulous site, and absence of flat cortical bone crest or when the patient wishes to wear a removable prosthesis during the healing period. The presented case report illustrates osteotome sinus floor elevation with and without grafting and simultaneous implant placement in extreme conditions: atrophic maxilla, short implant placement, reduced healing time, and single crown rehabilitation. After 6 years, all placed implants were functional with an endosinus bone gain.

Unusual Etiology and Diagnosis of Oroantral Communication due to Late Implant Failure

Oroantral communication (OAC) rarely occurs long after implant placement. The present report describes the rare etiology and the difficulty of the diagnosis of an uncommon OAC occurring 10 years after the implant placement in the posterior maxilla. The difficulty of the diagnosis lies in the absence of clinical symptoms of sinusitis and presence of multiunit prosthesis hiding implant failure. This case report supports the need for sinus check-up during a routine implant examination.