Edevaldo Tadeu Camarini

Osseointegrated Implant Fracture: Causes and Treatment

Despite its high success rate, therapy with osseointegrated dental implants is not free of complications. Among the problems that may occur is fracture of implants, which, albeit a rare phenomenon, may lead to unpleasant clinical outcomes for the patient, as well as for the clinician. Thus, it is paramount to know the factors related to the biological processes involved in maintenance of osseointegration and biomechanics applied to dental implants to prevent such complications, as well as treatment options available to deal with the problem. Therefore, the objectives of this work were to investigate the literature to identify causative factors that may lead to fracture of dental implants and to discuss available procedures.

Treatment of oral myiasis caused by Cochliomyia hominivorax: two cases treated with ivermectin

The term myiasis is applied to the injurious action that larvae of certain diptera cause to the organism of vertebrate animals in the living or dead tissue in which they grow. Because of its great destructive potential, appropriate and preventative treatment are necessary. Among the sites of infestation, the human mouth is a common site, mainly in tropical countries. We present two cases of oral myiasis caused by Cochliomyia hominivorax spp. Ivermectin is an extremely effective semi-synthetic macrolides, in the treatment of this condition.

Effect of mechanical loading on the removal torque of different types of tapered connection abutments for dental implants

STATEMENT OF PROBLEM The mechanical behavior of internal taper implant abutment designs needs to be evaluated. PURPOSE The purpose of this study was to evaluate the effect of simulated mechanical loading on the removal torque of 1-piece and 2-piece abutments connected to internal taper oral implants. MATERIAL AND METHODS Forty-eight internally notched taper implants were divided into 2 groups of 24. Group OP received solid (1-piece) abutments; group TP received esthetic (2-piece) abutments. Each group was further subdivided into subgroups C (control) without mechanical loading and T (test) with mechanical loading. In groups OPC and TPC, the abutments were placed and removed and the removal torque values (RTVs) registered. In groups OPT and TPT, abutments were placed, mechanically loaded (500 000 cycles), removed, and the RTVs registered. Groups TPC and TPT were further tested for the traction force necessary to dislodge the abutment from the implant. For data analysis, the Student t test (for RTVs) and the Mann-Whitney U test (for TFVs) (α=.05) were performed. RESULTS All abutments tested presented torque loss with RTVs lower than the placement torque. A statistically significant difference (P=.002) was found between groups OPC (81.6% of placement torque) and OPT mean RTVs results (85.0% of placement torque), while no statistical differences (P=.362) were found between groups TPC (63.7% of placement torque) and TPT (59.1% of placement torque). The traction force values necessary to dislodge the abutment from the implant, however, were significantly higher (P<.001) for group TPT than for group TPC. CONCLUSIONS Cold welding did not occur in any of the abutment specimens tested. Even after the mechanical loading, esthetic abutments presented similar RTVs. The traction force necessary to remove esthetic abutments from inside the implants presented a 2-fold increase after mechanical loading.

Comparative analysis of different joining techniques to improve the passive fit of cobalt-chromium superstructures

STATEMENT OF PROBLEM The influence of different joining techniques on passive fit at the interface structure/abutment of cobalt-chromium (Co-Cr) superstructures has not yet been clearly established. PURPOSE The purpose of this study was to compare 3 different techniques of joining Co-Cr superstructures by measuring the resulting marginal misfit in a simulated prosthetic assembly. MATERIAL AND METHODS A specially designed metal model was used for casting, sectioning, joining, and measuring marginal misfit. Forty-five cast bar-type superstructures were fabricated in a Co-Cr alloy and randomly assigned by drawing lots to 3 groups (n=15) according to the joining method used: conventional gas-torch brazing (G-TB), laser welding (LW), and tungsten inert gas welding (TIG). Joined specimens were assembled onto abutment analogs in the metal model with the 1-screw method. The resulting marginal misfit was measured with scanning electron microscopy (SEM) at 3 different points: distal (D), central (C), and mesial (M) along the buccal aspect of both abutments: A (tightened) and B (without screw). The Levene test was used to evaluate variance homogeneity and then the Welsch ANOVA for heteroscedastic data (α=.05). RESULTS Significant differences were found on abutment A between groups G-TB and LW (P=.013) measured mesially and between groups G-TB and TIG (P=.037) measured centrally. On abutment B, significant differences were found between groups G-TB and LW (P<.001) and groups LW and TIG (P<.001) measured mesially; groups G-TB and TIG (P=.007) measured distally; and groups G-TB and TIG (P=.001) and LW and TIG (P=.007) measured centrally. CONCLUSIONS The method used for joining Co-Cr prosthetic structures had an influence on the level of resulting passive fit. Structures joined by the tungsten inert gas method produced better mean results than did the brazing or laser method.

Surgical Management of Impacted Teeth Using Three-Dimensional Computed Tomography

The surgical removal of impacted, supernumerary, or ectopic teeth is a routine procedure to the dental surgeon. Because any and all surgical interventions involve anatomic considerations that predispose the patient to a high risk of incidents or complications, it is absolutely necessary to precisely determine the location of the enclosed teeth, to better plan the procedure. Even though the conventional radiographic techniques are commonly used to detect the presence of such teeth, they can present deficiencies. In those situations, additional examinations can be requested. In this article, we are reporting the case of a 12-year-old patient, whose third superior molars appeared in a very atypical position. We chose to request a computed tomography and three-dimensional manipulation of the obtained images. This article, as its main goal, highlighted the importance of computed tomography and of three-dimensional reconstructions as a tool to precisely determine the location of enclosed teeth, thus allowing for a better planning of the surgery and a safer surgical intervention.