The Influence of Saliva pH on the Fracture Resistance of Two Types of Implant-Supported Bis-Acrylic Resin Provisional Crowns—An In Vitro Study

Abstract

Temporary restorations play a fundamental role in oral rehabilitation. A properly adapted implant-supported provisional restoration implies better esthetics, contouring and architectural modeling of the upper peri-implant tissue. This study aimed to evaluate the influence of oral pH on the fracture resistance of implant-supported provisional restorations made with two brands of bis-acrylic resin (LuxaCrown® and Protemp™ 4) and to compare the fracture resistance of these two materials. Twenty crowns (ten manufactured using each brand) served as a control, and another forty crowns (twenty of each brand) were aged using artificial saliva with pHs of 4 or 7, for 7 days at 37 °C, in an attempt to simulate the behavior of these materials inside the oral cavity. Subsequently, all crowns were subjected to the application of a force at a constant speed, in a universal testing machine, until fracture was achieved. The LuxaCrown® brand showed greater resistance to fracture than the Protemp™ 4 brand. Salivary pH did not influence the fracture resistance of provisional LuxaCrown® crowns but did influence the fracture resistance of provisional Protemp™ 4 crowns.

Influence of Popular Beverages on the Fracture Resistance of Implant-Supported Bis-Acrylic Resin Provisional Crowns: An In Vitro Study

“…The saliva pH did not affect the fracture strength of the LuxaCrown ® provisional crowns, but it did affect the fracture strength of the Protemp™ 4 provisional crowns. The LuxaCrown ® provisional crowns, when exposed to artificial saliva with pH values of 4 and 7, exhibited a higher fracture strength than the Protemp™ 4 provisional crowns [ 3 ].…”

“…The fracture strength of temporary materials is subject to the geometry of the restoration and the aging processes that occur in clinical applications. Although the laboratory values of flexural strength under static load may not reflect intra0oral behavior, these values are useful for comparing materials under controlled situations and can be a useful predictor of clinical performance [ 3 , 4 ].…”

“…This is a state-of-the-art approach in implantology [ 1 , 2 ], which also allows for rehabilitation during the period of osseointegration, as well as restores the function, phonetics, esthetics, and adaptation to the final shape of the restoration. The temporary restoration plays a fundamental role in oral rehabilitation [ 3 , 4 ].…”

“…The fracture resistance of temporary materials is generally low compared to permanent restorative material, such as ceramics; parafunctional habits, diet, and time are important factors that influence the fracture resistance. Strength should also be considered when selecting a temporary material for clinical use [ 3 , 5 , 6 ].…”