Surface and mechanical properties of adhesives with calcium phosphates challenged to different storage media

Abstract

Aim: To evaluate the behavior of experimental dental adhesiveswith hydroxyapatite (HAp), alpha-tricalcium phosphate (α-TCP)or octacalcium phosphate (OCP) after storing them in threedifferent media: dry storage, distilled water, or lactic acid.Methods: An experimental adhesive resin was formulated withbisphenol A glycol dimethacrylate, 2-hydroxyethyl methacrylate,and photoiniciator/co-initiator system. HAp (GHAp), α-TCP(Gα-TCP), or OCP (GOCP) were added to the adhesive resin at 2wt.%, and one group remained without calcium phosphates tobe used as a control (GCtrl). The adhesives were evaluated forsurface roughness, scanning electron microscopy (SEM), andultimate tensile strength (UTS) after storing in distilled water(pH=5.8), lactic acid (pH=4) or dry medium. Results: The initialsurface roughness was not different among groups (p>0.05).GHAp showed increased values after immersion in water(p<0.05) or lactic acid (p<0.05). SEM analysis showed a surfacevariation of the filled adhesives, mainly for Gα-TCP and GHAp. GHApshowed the highest UTS in dry medium (p<0.05), and its valuedecreased after lactic acid storage (p<0.05). Conclusions:The findings of this study showed that HAp, OCP, and α-TCPaffected the physical behavior of the experimental adhesiveresins in different ways. HAp was the calcium phosphatethat most adversely affected the surface roughness and themechanical property of the material, mainly when exposed toan acid medium.

Wear Behavior and Surface Quality of Dental Bioactive Ions-Releasing Resins Under Simulated Chewing Conditions

“…The Mylar strip before resins' photoactivation during sample preparation should have helped achieve the smoothest possible surface. Different bioactive resins previously showed varied roughness depending, for instance, on their quantity of fillers [ 22 , 38 ]. The fillers' heterogeneity, content, size, or shape probably led to the present study's high roughness.…”

“…However, changes in the resin formulations to facilitate ion releasing may impact wear behavior making the material prone to physical modifications under masticatory load [ 18 ]. Few studies investigated bioactive fillers' effects in dental resins under high-challenge situations [ 18 , 21 , 22 ]. In this context, it is essential to consider that the oral environment and masticatory loads can induce high surface roughness, contributing to biofilm formation on the resin surface [ 23 ].…”

Assessment of Surface Roughness of a CAD – CAM Resin Nano-Ceramic ; a Bulkfill Resin Composite and a Universal Nanohybrid Ormocer Esthetic Restorative Materials with Different pH Changes

“…Also, it was reported that the effect of polishing systems on surface finish was material dependent (16) . The changes in pH related to the consumption of certain food and beverages was found to possess a direct correlation with the development of surface roughness in restorative materials (17)(18)(19)(20)(21) . Moreover, researches have been conducted to develop new monomers for resin matrices as well as to focus on the filler content, loading, and type and size of filler particles (22)(23)(24)(25)(26)(27) .…”