The Accuracy of New and Aged Mechanical Torque Devices Employed in Five Dental Implant Systems.

PURPOSE: Friction-style and spring-style torque wrenches are used to tighten implant abutments and prosthetic screws. The mechanical stability of these torque wrenches is crucial for the implant-abutment connection. The purposes of this study were to assess the performance of five brands (Straumann, Zimmer, Implant KA, Bredent, and Biohorizons) of wrench and to evaluate possible changes in applied torque values of aged wrenches. MATERIALS AND METHODS: Five new and aged wrenches that had been used approximately 250 times in a 1-year period were tested. The torque applied by friction- and spring-style wrenches was measured with a specially designed strain gauge indicator. Descriptive statistics, the one-sample t-test, and the independent-samples t-test were used to analyze values obtained from all torque wrenches. RESULTS: The accuracy of new and aged torque devices of all brands except Bredent differed significantly from the target values, but the mean values for aged and new wrenches did not differ significantly from each other (p > 0.05). Values for the spring- and friction-type torque wrenches deviated from the target values by 11.6% and 10.2%, respectively. CONCLUSION: The accuracy of aged torque wrenches is adequate for prosthetic screw tightening, but that of new torque wrenches is unsatisfactory and must be examined carefully before delivery.

In Vitro Evaluation of Manual Torque Values Applied to Implant-Abutment Complex by Different Clinicians and Abutment Screw Loosening.

Preload is applied to screws manually or using a torque wrench in dental implant systems, and the preload applied must be appropriate for the purpose. The aim of this study was to assess screw loosening and bending/torsional moments applied by clinicians of various specialties following application of manual tightening torque to combinations of implants and abutments. Ten-millimeter implants of 3.7 and 4.1 mm diameters and standard or solid abutments were used. Each group contained five implant-abutment combinations. The control and experimental groups comprised 20 and 160 specimens, respectively. Implants in the experimental group were tightened by dentists of different specialties. Torsional and bending moments during tightening were measured using a strain gauge. Control group and implants with preload values close to the ideal preload were subjected to a dynamic loading test at 150 N, 15 Hz, and 85,000 cycles. The implants that deformed in this test were examined using an optical microscope to assess deformities. Manual tightening did not yield the manufacturer-recommended preload values. Dynamic loading testing suggested early screw loosening/fracture in samples with insufficient preload.

Tooth extraction from a patient with cavernous hemangioma in maxillofacial region: case report.

Hemangiomas are benign vascular tumors which represent a rapid growth pattern followed by the involution phase. Generally, they are located in the soft tissues and are usually diagnosed in the first decade of life. Hemangiomas are mostly asymptomatic and rarely affect jaw bones. Mandible is affected more often than maxilla. If there is no complication present, treatment may not be necessary. Treatment planning of hemangiomas should be done by considering the location and the size of the lesion as well as the proximity to vital anatomical structures. The aim of this case report is to describe the procedures of tooth extraction in a patient who had been diagnosed as having maxillary cavernous hemangioma.

Monostotic fibrous dysplasia presenting in maxilla: a case report.

Fibrous dysplasia (FD) is a bone disorder in which fibrous tissue replaces normal bone. FD can be monostotic (10%-25%) or polyostotic (50-90%) and is typically diagnosed accidentally on radiographs. Craniofacial lesions are typically unilateral and are diagnosed by clinical assessment and radiographic evaluation. This report describes the case of a 50-yearold female patient who had presented with painless swelling of the right maxilla and was diagnosed with FD. Subsequent bone scintigraphy identified the lesion as monostotic. Based on the patient's age and the radiographic data, contour correction was performed. However, 1 year after surgery, the lesion regrew and the treatment was repeated.