Surface Deterioration of Indirect Restorative Materials

Abstract

The objective of this work was to evaluate the effects of in vitro and in situ biodegradation on the surface characteristics of two resin cements and a hybrid ceramic system. One hundred and eighty specimens (4X1.5mm) of each material (Maxcem Elite, NX3 Nexus and Vita Enamic) were made and randomly distributed in twelve groups (n=15) according to the material and biodegradation method. The specimens were then submitted to the following challenges: storage in distilled water 37 ºC for 24 h or 7 days, storage for 7 days, at 37 ºC, in stimulated saliva or in situ. The in situ stage corresponded to the preparation of 15 intraoral palatal devices, used for 7 days. Each device presented 3 niches, where a sample of each materials was accommodated. Specimens from both saliva and in situ groups suffered a cariogenic challenge, corresponding to the application of a solution of 20% of sucrose, 10 times throughout each day. After each biodegradation method, the surface roughness (Ra), Vickers hardness (VHN) and scanning electron microscopy (SEM) analyzes were performed. The data collected were evaluated by Levene test, two-way ANOVA and Tukey`s test (α=5%). The in situ challenge promoted the greater biodegradation, regardless of the material. Regarding the materials, the Vita Enamic VHN was negatively affected by all biodegradation methods and the Nexus NX3 presented better performance than the self-adhesive cement tested. Therefore, within the conditions of this work, it was concluded that in situ biodegradation can affect negatively the surface characteristics of indirect restorative materials.

The impact of different cleaning protocols on resin bond strength to polymer-infiltrated ceramic material

“…For this in-vitro study, forty plates of Vita Enamic ceramic were prepared from polymer infiltrated ceramics (VITA ENAMIC blocks 3M2-HT-EM-14,VITA-Zahnfabrik, Bad Säckingen, Germany) into the dimensions (10mmX7mm and 2mm in thickness) by aid of a low speed, water-cooled diamond saw (Isomet 4000, buchler ltd, Lake Bluff, IL, USA). (33) All plates were inspected under microscope for presence of any cracks, then treated with air-borne particle abrasion using 50µm Al 2 O 3 (Basic Eco SandBlaster, Renfert, Hilzingen, Germany ), under 2.5 bars pressure for (3654) 15sec. and a distance of 10mm, and cleaned ultrasonically.…”

Interaction between microorganisms and dental material surfaces: general concepts and research progress

“…In addition, Mushashe et al [ 95 ] showed that its impact on the restorative materials was related to the material parameters, and all the changes in the properties of the materials were caused by biodegradation. Therefore, it is certain that although each material mounts different responses to microorganisms, the oral environment can impact the surface characteristics of restorative materials.…”

Influence of curing modes on thermal stability, hardness development and network integrity of dual-cure resin cements

“…Highly cross-linked polymer chains are more resistant to solvent degradation and water uptake because free volume is reduced and limited pathways are available for solvent molecules to diffuse in and out of the highly cross-linked structure [13,14]. By contrast, solvents can penetrate and soften both low cross-linked polymers or linear chains [13][14][15].…”