Implant crest module: A review of biomechanical considerations.

The success of dental implants has long been established through various studies with a particular emphasis laid on an implant design. Crest module is that portion of a two-piece metal dental implant, designed to hold the prosthetic components in place and to create a transition zone to the load bearing implant body. Its design, position in relation to the alveolar crest, and an abutment implant interface makes us believe that, it has a major role in integration to both hard and soft tissues. Unfortunately, in most clinical conditions, early tissue breakdown leading to soft tissue and hard tissue loss begins at this region. Early crestal bone loss is usually highest during the first year after placement ranging from 0.9 to 1.6mm and averaged 0.05-0.13mm in the subsequent years . Various hypotheses have been stated to reason it however, none has been proved convincingly. In light of this, various attempts have been made to overcome this undesirable bone loss, by varying an implant design, the position, surgical protocol, and the prosthetic options. Irrespective of an implant system and designs that are used, crestal bone loss of up to the first thread is often observed. The purpose of this review is to look into the various designs and treatment modalities, which have been introduced into the crest module of an implant body to achieve the best biomechanical and esthetic result.

Clinical, histologic, and histometric evaluation of implants with microthreaded crest module and SLA surface / 대한치주과학회지

BACKGROUND: Crestal bone loss known as saucerization is a frequently observed phenomenon. Recent studies have shown that implants with micothreaded crest module reduced the force concentration in the crestal region thus resulting in no or reduced crestal bone loss. This study presents a clinical, histologic, and histometric evaluation of implants with microthreaded crest module and SLA surface. METHODS: The implants were placed in the mandible of 5 beagle dogs weighing 10-15kg. Four premolars were bilaterally extracted 8 weeks prior to implant placement. Mucoperiosteal flap was elevated and drilling with increasing diameter was performed under saline irrigation. After countersinking 2 implants were placed in each side resulting in 4 implants per dog. Healing period of 8 weeks was allowed before sacrificing the animals. Histologic preparation was performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. T-test was used for statistical analysis with pvalue p<0.05. RESULTS: 1. Healing was uneventful without any cover screw exposure. New bone formation around the implants was observed without any inflammatory infiltration. 2. Bone to implant contact in the microthread and thread were 43.90 +/- 20.30 %, and 53.19 +/- 20.97 % respectively. The overall bone to implant contact was 48.54 +/- 20.95 %. 3. Percentage of bone area inside threads were 54.43 +/- 10.39 %, and 38.44 +/- 16.44 % for the microthread and thread respectively. There was statistically significant difference(p<0.05). The overall percentage of bone area inside threads was 46.67 +/- 15.68 %.