The effect of toothbrush abrasion on wear and surface roughness of direct and indirect composite laminate veneer restorations

Abstract

Direct and indirect composite laminate veneers have been frequently used, however the wear of composite restorative materials is still a major problem. Objective: This study aimed to investigate the surface roughness and wear of composite laminate veneers made by two different methods after toothbrushing simulation. Material and Methods: Ninety-six upper incisors and canines were divided into two groups: 1-Componeer prefabricated composite veneer (CPV), 2-Uveneer direct composite veneer (UDV). At the UDV group, restorations were made by using Uveneer template system with the same nanofilled composite material (Synergy D6, Coltène, Altstatten, Switzerland) of the prefabricated Componeers'. The initial surface roughness was measured with a profilometer, then the weight was measured. Before the simulation, samples were screened with a 3D extra-oral scanner. Toothbrush simulation was performed at 10,000 rotational strokes with 2.5 N. The measurements were repeated after toothbrushing simulation. Data were analyzed using variance analyses and t-tests (p<0.05). Results: Before and after polishing, a significant difference was found between two groups' surface roughness in both lateral incisors (p=0.000, p=0.000) and canines (p=0.048, p=0.001), respectively. After toothbrushing simulation, significant increases were observed in central and lateral incisors' surface roughness with two methods. There was no significant difference between weight loss (p>0.05). In 3D scans, wear rate was quite similar except UDV group central incisors. Conclusions: Surface roughness of the CPV restorations were less affected after toothbrushing simulation. However, the Uveneer template system, a facilitated treatment procedure compared to the manual buildup of direct restoration, has shown comparable results with CPV's. RECEIVED

Surface Characterization and Tribological Performance Analysis of Electric Discharge Machined Duplex Stainless Steel

“…However, the machined specimen was found with black patches that symbolized the tribochemical reaction (specimen surface wear in the high oxide atmosphere) ( Figure 7 b). Moreover, the machined surface was noticed with light scratches and no delamination that reveal the high wear resistance of the substrate [ 42 , 43 , 44 ]. Evidently, electric discharge machining at elevated temperature results in the chemical reaction between the dielectric fluid and the workpiece material elements.…”

Photographic analysis of orofacial soft tissue alterations related to rapid maxillary expansion in pediatric patients

“…Numerous studies have utilized cone beam computed tomography (CBCT) images and 3D facial scans to assess changes in soft tissue following RME [29][30][31][32][33][34][35]. However, the use of 3D imaging systems in pediatric patients is limited, typically reserved for cases involving serious craniofacial anomalies or syndromes due to the high radiation dose associated with these scans [36][37][38].…”

The influence of orthopedic rapid maxillary expansion on the deviation of the nasal septum

“…Although many studies have investigated the impact of RME on the size of the nasal cavity and airway [24][25][26][27], the data on the effects of RME on the nasal septum are limited. Previous studies have used PA cephalometric radiographs [3,14,27,28], which provide two-dimensional evaluation, or 3D imaging systems (i.e., cone beam computed tomography (CBCT)) [7,18,24,29,30] to assess the dimensions of the nasal cavity or any nasal septal alterations caused by RME. While CBCT scans can provide accurate 3D diagnosis of NSD in imaging studies [18,22], their excessive radiation dose limits their routine use in orthodontic clinics for diagnosing maxillary skeletal transversal constriction in pediatric patients [31].…”