WITHDRAWN: Interventions for replacing missing teeth: 1- versus 2-stage implant placement.

BACKGROUND: Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention. OBJECTIVES: To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure. SEARCH METHODS: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching included several dental journals. Authors of all identified trials, an Internet discussion group and 55 dental implant manufacturers were contacted to find unpublished randomised controlled trials (RCTs). The last electronic search was conducted on 21 January 2009. SELECTION CRITERIA: All RCTs of osseointegrated dental implants comparing the same dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. MAIN RESULTS: Five RCTs were identified and included reporting data on 239 patients in total. On a patient, rather than per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured 2-stage (submerged) implants. AUTHORS' CONCLUSIONS: The number of patients included in the trials was too small to draw definitive conclusions. The 1-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a 2-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability or when barriers are used for guided tissue regeneration, or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments especially in fully edentulous patients.

Interventions for replacing missing teeth: 1- versus 2-stage implant placement.

BACKGROUND: Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention. OBJECTIVES: To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching included several dental journals. Authors of all identified trials, an Internet discussion group and 55 dental implant manufacturers were contacted to find unpublished randomised controlled trials (RCTs). The last electronic search was conducted on 21 January 2009. SELECTION CRITERIA: All RCTs of osseointegrated dental implants comparing the same dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. MAIN RESULTS: Five RCTs were identified and included reporting data on 239 patients in total. On a patient, rather than per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured 2-stage (submerged) implants. AUTHORS' CONCLUSIONS: The number of patients included in the trials was too small to draw definitive conclusions. The 1-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a 2-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability or when barriers are used for guided tissue regeneration, or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments especially in fully edentulous patients.

One-stage versus two-stage implant placement. A Cochrane systematic review of randomised controlled clinical trials.

OBJECTIVES: To evaluate if a one-stage implant placement procedure is as effective as a two-stage procedure. DATA SOURCES: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE, were searched and several journals were hand-searched with no language restriction up to January 2009. REVIEW METHODS: All randomised controlled trials (RCTs) of osseointegrated dental implants comparing the same dental implants placed according to one- versus two-stage procedures with a minimum follow up of 6 months after loading were eligible. Screening of studies, quality assessment and data extraction were conducted in duplicate. Outcome measures were: prosthesis failure, implant failures, radiographic marginal bone level changes, patient preference including aesthetics, aesthetics evaluated by clinicians and complications. RESULTS: Five RCTs were identified and included reporting data on 239 patients in total. On a patient basis, rather than a per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured two-stage (submerged) implants. CONCLUSIONS: The number of patients included in the trials was too small to draw definitive conclusions. The one-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a two-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability, when barriers are used for guided tissue regeneration or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments, especially in fully edentulous patients.

Spontaneous regression of bilateral dentigerous cysts: a case report.

UNLABELLED: A dentigerous cyst is the most common developmental odontogenic cyst and believed to be slowly progressive in nature. This case report describes an incidental finding of spontaneous regression of bilateral dentigerous cysts associated with lower impacted third molars in a 30-year-old, fully dentate female. Together with three other similar reports, a few possible explanations are postulated and the understanding of natural history of dentigerous cysts is questioned. CLINICAL RELEVANCE: The discovery of a dentigerous cyst in a patient always warrants special attention. This article highlights the fact that surgical treatment is not the only solution for a dentigerous cyst and, in rare cases, conservative management can save the patient from having unnecessary surgery.