Today’s topic on :- Medical related + Implant + Regenerating bone + Dentists + Dental related + Information
To know about regenerating bone
||Medical + Dentist’s =Article By Amit Kumar [ mydatawords.com ] | Updated : August 12, 2020 ||
Implants placed in regenerating bone in a prerequisite for long-term successful implant outcomes is a sufficient amount of bone at the implant site in both vertical and horizontal dimensions. However, bone volume is frequently lacking as a result of trauma or infectious diseases such as advanced periodontists. After tooth extraction, the anterior maxilla exhibits significant alveolar bone remodeling with a mean alveolar bone loss of 1.5 to 2 mm (vertical) and 40% to 50% (horizontal) in 3 to 6 months.In the absence of restorative complications, continued bone loss of up to 40% to 60% of the ridge volume occurs during and the loss of horizontal and vertical bone height leads to great challenges in dental implant placement.
This lack of sufficient bone volume can jeopardize the implant success and survival rate and, in some cases, the final esthetic outcome.A number of different techniques have been developed to reconstruct deficient alveolar ridges to allow dental implant placement in either a simultaneous or staged approach. The first preclinical studies on guided bone regeneration (GBR) were published in 1988 and 1989 using rat and rabbit models [ i will explain later about that ]. Continue….
According to the principle, a secluded space was created around a bone defect to allow for proper blood clot formation, blood vessel budding, and the slow-migrating progenitor cell to colonize the defect without the competition of epithelial and connective tissue cells. Nonresorbable polytetrafluoroethylene (PTFE) and bio-absorbable barrier collagen membranes were used to create space maintenance around the bone defect.
The GBR biologic concepts were applied to partially edentulous atrophic mandibles in 1994 to achieve vertical bone regeneration with the aid of titanium-reinforced non resorbable membranes.By the late 1990s, small variations including autogenous and freeze dried bone to fill the defect under the membrane were developed to enhance vertical bone growth, allowing a vertical gain of 7 mm or more. Nevertheless, extra- or intra oral harvesting of autogenous bone was associated with a high degree of patient discomfort and morbidity.
Hence, efforts were applied to decrease the volume of autogenous bone harvested by applying different ratios of autogenous bone and osteogenic biomaterials under the expanded PTFE (e-PTFE) membranes for vertical bone regeneration. The e-PTFE membrane was the most investigated barrier used for vertical GBR and therefore was considered the gold standard for this procedure. Recently a less porous form of PTFE (dense PTFE, d-PTFE) has been compared to e-PTFE in a randomized controlled clinical trial, As reported that the two different membranes showed identical clinical results. Starting in 1996, the intent of clinicians and researchers was to verify the procedure in terms of efficacy and safety. The long-term implant stability and resorption patterns of bone regenerated with this technique were reported in a retrospective multicenter study of 1 to 5 years of prosthetic loading evaluating 123 implants inserted in atrophic alveolar ridges either at bone augmentation or after a healing period.
Another study demonstrated a high clinical success rate (94.7%) of 81 implants placed in vertically regenerated bone after a mean follow-up time of 40.3 months.A recent retrospective study reported the clinical and radio- graphic results obtained from 91 machined implants placed in vertically regenerated bone in 33 patients after a mean follow-up time of 15 years.The study population was derived from patients who received a vertical GBR procedure between 1993 and 2000 and cumulative implant survival rate (94%). The radiographic analysis showed marginal bone loss between the first year of function and (after 13 to 21 years) of 1.02 mm, which suggests high dimensional stability of the vertically augmented bone. Only 9.9% of the implants showed moderate and slow progressing bone resorption.
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