This study aimed to measure the preload in different implant platform geometries based on micro-CT images. External hexagon (EH) implants and Morse Tapered (MT) implants (n=5) were used for the preload measurement. The abutment screws were scanned in micro-CT to obtain their virtual models, which were used to record their initial length. The abutments were screwed on the implant with a 20 Ncm torque and the set composed by implant, abutment screw and abutment were taken to the micro-CT scanner to obtain virtual slices of the specimens. These slices allowed the measurement of screw lengths after torque application and based on the screw elongation. Preload values were calculated using the Hooke's Law. The preloads of both groups were compared by independent t-test. Removal torque of each specimen was recorded. To evaluate the accuracy of the micro-CT technique, three rods with known lengths were scanned and the length of their virtual model was measured and compared with the original length. One rod was scanned four times to evaluate the measuring method variation. There was no difference between groups for preload (EH = 461.6 N and MT = 477.4 N), but the EH group showed higher removal torque values (13.8 ± 4.7 against 8.2 ± 3.6 N cm for MT group). The micro-CT technique showed a variability of 0.053% and repeatability showed an error of 0.23 to 0.28%. Within the limitations of this study, there was no difference between external hexagon and Morse taper for preload. The method using micro-CT may be considered for preload calculation.

Patients with severe parafunctional habits can have a reduction of their occlusal vertical dimension (OVD) and may create complex cases of oral rehabilitation, in which the patient may develop occlusal, masticatory and psychological problems. Objective:To report a clinical case of restoration of masticatory function and aesthetics from the production of tooth/implant-supported prostheses with conservative preparations, reestablishing the OVD and occlusal stability. Case report: Patient MVN, 55 years old, wheelchair user, presenting bruxism with a history of gastric reflux due to hiatal hernia, attended the clinic at the University complaining of dental sensitivity, difficulty in chewing and aesthetic smile commitment.At clinical examination it was found widespread wear of teeth. Radiographic examination showed good periodontal health and dental implants in good condition of osseointegration. The OVD was established from the VDR and confirmed by the metric method. The initial casts were positioned on the articulator for diagnostic waxing. From the waxing it was possible to make provisional fixed tooth/implant-supported prostheses. In the lower arch, the prosthesis was screwed on the implants #35, #37, #46, and #47, with the remaining teeth working as an auxiliary support, while in the upper arch two interim prosthesis were made, one for the elements #16 and #17 (tooth-supported) and one for the elements #13, #12, #11, #21, #22, #23, #24 (tooth/implant-supported). Thus, the OVD and the aesthetics lost by bruxism abrasion were restored. Conclusion:This case demonstrates the importance of the provisional prostheses for aesthetic and functional rehabilitation of patients with severe worn dentition.

Background: Temporomandibular joint disorder (TMD) can significantly affect the quality of life of individuals. However, evidence of TMD involvement and the extent of the impacts caused by it, in groups exposed to a stressful routine, are still scarce. Therefore, the aim of the present study was to evaluate the prevalence of TMD signs and symptoms and their impact on quality of life related to oral health in construction workers. Material and methods: This cross-sectional study included only male individuals. Illiterate workers and functional illiterate were excluded. The diagnosis of TMD was established according to the Research Diagnostic Criteria for TMD (RDC/TMD). The Oral Health Impact Profile questionnaire validated for Portuguese (OHIP-14) was used to assess the impact of TMD on oral health and quality of life. Descriptive analysis of TMD signs and symptoms was performed. Data related to the OHIP-14 questionnaire were compared using the Mann-Whitney U test. Pearson's correlation was also performed. The established alpha of this study was 5%. Results: 230 individuals were included. The mean age was 37.8 (SD=11) years. The most frequent TMD sign and the symptom was disc displacement, 86 (37.39%) of the individuals. OHIP-14 demonstrated a statistically significant difference when

Since its introduction in 2014, the PowerScope device has undergone some modifications to improve and facilitate its clinical use. This article describes the latest innovation in the device, which consists of an alternative attachment nut. With this new nut, the concept changes a little because we are going to install the nut outside the patient’s mouth and not directly in his mouth as we did with the first two generations of the nut. The alternative attachment nut is another option for using the PowerScope. It is up to the orthodontist to decide which option best fits his way of working: continue with nut 2 (from 2015); use the alternative nut on the upper and lower arches; Use alternate nut on the upper arch and nut 2 on the lower arch.

Purpose: The aim of this study was to evaluate the physical-mechanical properties of experimental orthodontic resins, containing different photoinitiators systems and photoactivated through a ceramic bracket, using a high irradiance and wide spectrum light emitting diode curing unit. Methods: Experimental resin composites (50:50 BisGMA/TEGDMA: 60% feldspar silanized particles) were formulated with different photoinitiators according to the following groups: phenylpropaneamine + amine DMAEMA (PPD), camphorquinone + amine DMAEMA (CQ) or bisacylphosphinic oxide (BAPO). A commercial orthodontic resin composite (Transbond XT) was used as control. The materials were then distributed into two groups, according to the photoactivation condition: directly or through a ceramic bracket, for 20s at 1200 mW/cm2. In the sequence, fifteen composite disks, 5mm of diameter and 1mm of thickness, were made for each of the eight groups. The degree of conversion (DC) was determined by means of Raman spectroscopy. Knoop hardness (KHN) was measured immediately after confection and after 24 hours of storage in 100% ethanol for indirect crosslink density (CLD) evaluation. Data were analyzed using two-way ANOVA followed by Tukey's test (α = 0.05). Results: The DC of the BAPO composite was significantly higher in comparison to the other materials, regardless of the photoactivation condition. The KHN was significantly different between the composite groups in the following sequence: BAPO> Transbond XT> CQ> PPD. The direct photoactivation presented higher KHN values, regardless the type of material. Regarding the CLD, there was statistical difference only for the material factor, as follow: PPD> BAPO = CQ = Transbond XT. Conclusion: The photoinitiator type and the photoactivation condition had a significant influence on the physical-mechanical properties of the evaluated materials.