Biomechanical behavior of extra-narrow implants after fatigue and pull-out tests.

STATEMENT OF PROBLEM: Narrow implants have limited indications, and implant fracture may occur when these indications are not followed. PURPOSE: The purpose of this in vitro study was to investigate the mechanical behavior of a 2.9-mm-diameter implant using a fatigue limit test and to investigate the Morse effect of 2 different Morse taper systems, 2.9-mm-diameter (FAC group) and 3.75-mm-diameter (CM group) implants, using a pull-out test. The null hypothesis was that the tensile strengths of the components for both systems would be similar. MATERIAL AND METHODS: The fatigue properties of 13 specimens under 6 loads were determined. The test was performed at 15 Hz and for 5×106 cycles. In the pull-out test, the specimens were divided into 2 groups (n=8), the FAC group (2.9-mm-diameter) and the CM group (3.75-mm-diameter). Statistical analysis for the pull-out test was performed with the Student t test (α=.05). RESULTS: Thirteen specimens underwent the fatigue test. Only 5 did not fail when subjected to the frequency and number of cycles examined. Three of the specimens did not fail under a load of 130 N. The pull-out test showed a significant difference between the FAC and CM groups (P<.001). CONCLUSIONS: According to the fatigue test, the extra-narrow implant (Facility; Neodent) was compatible with the low masticatory effort regions, as indicated by the manufacturer. The better performance of the FAC group in the pull-out test may be due to its design, which promotes the pure Morse effect in the implant-abutment interface, and the angulation of its internal conical portion.

Avaliação da higiene oral em prótese fixa múltipla sobre implantes expostos após necrose óssea ­ relato de caso / Evaluation of oral hygiene in multiple fixed prostheses on implants exposed after bone necrosis ­ case report

Alguns pacientes podem apresentar dificuldades motoras que inviabilizam a adequada higienização de próteses implantossuportadas. No entanto, a utilização de escovas elétricas pode compensar essas dificuldades e melhorar a qualidade de higiene oral. O presente trabalho relata um caso clínico que utilizou escova dental elétrica Philips Sonicar e AirFloss Ultra® como meio de higienização da área de implante osseointegrado exposta pós necrose óssea. Paciente dirigiu-se a um serviço de reabilitação oral com desconforto em prótese implantada ferulizada de três elementos localizada no arco inferior direito. Após análise clínica e diagnóstico, o paciente foi orientado quanto as etapas do tratamento, assim como a necessidade da manutenção dos tecidos peri-implantares através de uma correta higienização. Após um ano é possível verificar uma condição satisfatória da região avaliada e maior satisfação do paciente quanto ao método de limpeza empregado. (AU).

Some patients may present motor difficulties that prevent the adequate hygiene of implanted prosthesis. However, the use of electric toothbrushes can compensate these difficulties and improve the quality of oral hygiene. The present study reported the case of a patient who used Philips Sonicar electric brush and AirFloss Ultra® to clean an osseointegrated implant area exposed after bone necrosis. Patient went to an oral rehabilitation service with discomfort in a three-element splinted implanted prosthesis area, located in the lower right arch. After clinical analysis and diagnosis, the patient was advised on the steps of treatment as well as the necessity of the maintenance of the peri-implant tissues with a correct oral hygiene. After one year, it is still possible to verify a satisfactory condition of the evaluated region and greater satisfaction of the patient regarding the cleaning method employed. (AU).

Comparative analysis of optical microscopy, scanning electron microscopy, and micro-computed tomography on measurements

Abstract: Microscopic measurements are widely used in scientific research and the correct equipment to perform these evaluations could be critical to determine study results. Regarding microscopic measurements, three of the most used methods are: Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Micro-computed Tomography (MCT). It is important to select the best method for assessing diverse parameters, considering operational characteristics of the method, the equipment efficiency, and the machinery cost. Aim: Therefore, the main objective of this study was to define which is the most useful measurement method for assessing magnitudes below 0.4 mm. Methods: Ten dental implants, with known dimensions as defined by the manufacturer were randomly distributed. Two blinded observers assessed the distance between the second and the third screw vortex of the implants using three suggested methods. The true distance was defined to be 0.5 mm. Results: The assessed distances were: 0.597±0.007mm for OM, 0.578±0.017mm for SEM, and 0.613±0.006mm for MCT. The assessed distances were significantly different when the methods were compared (P>0.01). All measurements were into the CAD tolerances. Conclusion: It was possible to conclude that linear easurements between 595 and 605 µm could be performed by any of the described technologies (AU)

Influence of dentistry procedures on masticatory function of dentate patients

Aim: Evaluate the masticatory performance in patients with different clinical situations: patients with natural dentition without restorative and/or orthodontic intervention (Group CG) and patients with restorations and/or orthodontic intervention (Group TG). Subjects received instruction before the experiment, related to masticatory movements. Methods: Three capsules containing the granules were delivered separately to chew for 20 seconds each, controlled by the examiner. One capsule was chewed for 20 seconds only on the left side; the second capsule was chewed for 20 seconds only on the right side; and the third capsule was chewed for 20 seconds to simulate each patient's mastication. The mean data and standard deviation of masticatory function of each patient was calculated. Results: The results obtained in this study showed that there were no statistically significant differences (P < 0.05) between both tested groups (0.0320 ± 0.00716, 0.0436 ± 0.00974). Conclusions: Patients who were submitted to orthodontic and/or restorative procedures, with balanced occlusion could be used as a control group, making easier the patient recruitment. Clinicians and researchers on masticatory performance evaluation could apply the colorimetric method. The colorimetric method was a standardize method, effective and easy to execute. (AU)