Rodolfo Bruniera Anchieta

This study aims to show a surgery-prosthetic resolution of complex atrophic maxillae with bone grafts, implants, and fixed implant prostheses in an elderly patient with radiographic follow-up. This article describes the clinical case of an elderly woman, 65 years old, who lost all superior teeth when she was 25 years old and had severe atrophic maxillae. Due to the maxillae, bone situation was planned an osteotome for sinus floor elevation and an allogeneic bone graft followed. After 16 months of bone integration, seven osseointegrated implants were placed. After 6 months of implant osseointegration, a complete fixed implant denture. Is it possible to conclude that using advanced surgical and prosthetic planning is possible to recover the esthetic and function of a severe and complex clinical case.

Purpose: The structural integrity of the resin cement layer, the bond strength, and the biomechanical behavior of different fiberglass post cementation techniques were evaluated.Methods: Thirty-three bovine incisors were divided into three groups (n = 11): conventional fiberglass post (CFP), conventional fiberglass post in flared root canals (CFL), and relined fiberglass post (RFP). Six specimens from each group were submitted for high-resolution microcomputed tomography (μCT) to evaluate the integrity and presence/volume of voids at the resin cement layer. Finite element analysis (FEA) of two three-dimensional (3D) models of each group were conducted, one considered ideal (without interface defects) and another containing the conditions identified in the μCT analysis. Push-out bond strength tests were conducted for all specimens.Results: The CFL group had the greatest mean values of void (Thirds cervical: 73.67; middle: 95.67; apical: 47.33) and gap concentration (Thirds cervical: 14.67; middle: 15.83; apical: 8.33) compared with CFP and RFP. A significant difference in bond strength was observed between the cervical (1.33 MPa) and middle thirds (1.85 MPa) compared with the apical third (4.85 MPa) of the CFL. A significant difference was observed in the bond strength in the CFL (1.33 MPa) and RFP (3.29 MPa) in the cervical third, which were statistically similar to the bond strength of the CFP. The tensile stress distributions were similar in most structures, localized in the cervical region on the lingual surface.Conclusion: Structural defects in the interface layer might influence the bond strength and biomechanical behavior under the different fiberglass post cementations.

Introduction: Implant-supported prostheses are an excellent treatment option for totally edentulous patients, however, some conditions, such as extremely atrophic jaws, may limit their application. Aims: to demonstrate and discuss, through a series of clinical cases, the functional aesthetic resolution of totally edentulous patients with atrophic maxillae, using three different implant-prosthesis approach. Methods and Material: This article describes a clinical case series of patients has between 65 and 75 years old, who lost all upper teeth and had severely atrophic jaws. Due to the bone situation of the maxilla, an osteotome was planned for sinus floor elevation and followed by an allogeneic bone graft. After 18 months of bone integration, osseointegrated implants were installed and different prostheses were made for each case. Conclusions: It is possible to conclude that with the use of advanced surgical and prosthetic planning it is possible to recover the aesthetics and function of a serious and complex clinical case.

The aim of this study was to evaluate the Knoop microhardness and the microtensile bond strength of a second-generation of bulk-fill (BF) and a nanohybrid composite resins (NH) in different thicknesses of increments. For this, ninety disks of composite resin were made for Knoop microhardness, being divided into six groups (n = 15). The Knoop microhardness obtained in each millimeter of the internal face. For microtensile bond strength, ninety restored in third molars were used, divided into six groups (n = 15). For Knoop microhardness, the Wilcoxon and Friedman test was used. For the microtensile bond strength were used the Two-way Anova test and Tukey's post-test (p <0.05). The NH resin showed higher Knoop micro hardness than BF and it was observed that hardness value decreases as increases the thickness of the resin. There was no significant difference in microtensile bond strength comparing NH and BF. However, there was a significant difference between G2 and G4 for the NH groups, with the highest and lowest bond strength values, respectively. Thus, the new generation of the bulk-fill composite resin provided lower microhardness values as the thickness of the increments increases in comparison with the nanohybrid composite resin. The microtensile bond strength does not appear to have been influenced by the type of resin, or the thickness of the increment.

The aim of this study was to evaluate the influence of the polishing period on surface roughness (Ra) before and after thermal aging in four composite resins - CR (Durafill VS, Vittra APS, Filtek Z350XT and Spectra Smart). This in vitro study evaluated: (1) CR in 4 levels; (2) polishing period (PP) in three levels (immediate, 7 and 14 days) and (3) artificial aging in two levels: without aging and after 10,000 cycles. For this, 240 CR specimens were allocated into 12 groups (n=20) according to PP with SofLex Pop On disks. For Ra, 3 measurements on the top surface of each specimen were performed with a diamond tip and constant load of 4mN and 0.25mm/s. Next, the specimens were aged in thermocycling, with temperatures of 5° and 55°C, during 30 seconds in each temperature, and repeated testing afterwards. The data were submitted to statistical tests with 5% significance. The alteration in Ra was observed only in the late polishing in the period of 7 days, where the Durafill VS CR showed higher Ra in comparison to the other CRs. After thermocycling, the groups showed significant difference only with late polishing in the 21-day period; the nanoparticulated RCs (Z350XT˂Vittra APS) recorded the highest Ra values, followed by the microhybrid (DurafillVS) and nanohybrid (Spectra Smart) RCs, respectively. Thus, late polishing in the 7-day and immediate period provided higher Ra values, especially for the nanohybrid and microhybrid composite resins.

To evaluate the stress behavior of ceramic fragment restoration, varying the thickness of the cement layer and intraoral temperature variation. A solid model of a upper lateral incisor was obtained and a defect at enamel distal/incisal edge was restored with a ceramic fragment. Based on this initial model, 4 different models (M) were built: M1 – absence of cement layer (CL) (0 μm of thickness); M2 – CL with an uniform thickness of 50 μm; M3 – CL with 50 μm at the margin of ceramics and 100 μm in the inner area far from margins; M4 – CL with 50 μm at the margin of ceramics and 200 μm in the inner area far from margins. The environment temperature changed from 5 °C to 50 °C in 4 increments. The finite element analysis was performed. Increase the cement layer thickness generated higher stress levels on ceramic surface in all temperatures, as well as on cement interface. In general hot temperature was the worst scenario for ceramic fragments integrity, since tensile and compressive stress were more intense. The maximum principal stress on ceramic fragment was found 90 MPa for M4 at 50 °C, followed for M3 (87 Mpa). For CL, the peak of stress was found for M3 at 5 °C (47 MPa). Is it possible to conclude that thick resin cement layer contribute to higher stress concentration on ceramic fragment, and extremely hot temperatures increase the risk of structural failure, since both ceramic and \cl are exposed to higher compressive and tensile stresses.

The aim of this article is to describe the procedure for sealing the screw access channel using plastic tape, polytetrafluoroethylene, in screw- or cement-retained implant-supported prostheses. This technique is viable and easily performed, and the functional and esthetic results are satisfactory.