Bond Strength of Universal Adhesives to Dentin: A Systematic Review and Meta-Analysis.

Louis Hardan,Davide Mancino,Youssef Haikel,Naji Kharouf,Maciej Zarow,Natalia Jakubowicz,Rim Bourgi,Carlos Enrique Cuevas-Suárez

doi:10.3390/polym13050814

Abstract

Currently, the availability of a wide variety of universal adhesives makes it difficult for clinicians to choose the correct system for specific bonding situations to dentin substrate. This study aimed to determine whether there are any alternative techniques or additional strategies available to enhance the bond strength of universal adhesives to dentin through a systematic review and meta-analysis. Two reviewers executed a literature search up to September 2020 in four electronic databases: PubMed, ISI Web of Science, Scopus, and EMBASE. Only in vitro studies that reported the dentin bond strength of universal adhesives using additional strategies were included. An analysis was carried out using Review Manager Software version 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). The methodological quality of each in vitro study was assessed according to the parameters of a previous systematic. A total of 5671 potentially relevant studies were identified. After title and abstract examination, 74 studies remained in systematic review. From these, a total of 61 studies were included in the meta-analysis. The bond strength of universal adhesives to dentin was improved by the use of one of the following techniques: Previous application of matrix metalloproteinases (MMP) inhibitors (p < 0.001), prolonged application time (p = 0.007), scrubbing technique (p < 0.001), selective dentin etching (p < 0.001), non-atmospheric plasma (p = 0.01), ethanol-wet bonding (p < 0.01), prolonged blowing time (p = 0.02), multiple layer application (p = 0.005), prolonged curing time (p = 0.006), and hydrophobic layer coating (p < 0.001). On the other hand, the use of a shortened application time (p = 0.006), and dentin desensitizers (p = 0.01) impaired the bond strength of universal adhesives to dentin. Most of the analyses performed showed a high heterogenicity. The in vitro evidence suggests that the application of universal adhesives using some alternative techniques or additional strategies may be beneficial for improving their bonding performance to dentin. This research received no external funding. Considering that this systematic review was carried out only with in vitro studies, registration was not performed.

Highlights

Despite the enormous improvements made in adhesive technology throughout the last 50 years, there are still some unresolved problems regarding the durability of the adhesive interface [1]
The aim of this study was to evaluate whether, in vitro, the immediate and long-term bonding performance of universal adhesives to dentin would be improved by the use of any additional strategies through a systematic review and meta-analysis
A reduction in the expression and activity of matrix metalloproteinases (MMP)-2 and MMP-9 could be possible by applying a non-atmospheric plasma on thyroid papillary cancer cells [103]. Both immediate and aged bond strength were improved by the application of selective dentin etching for 3 s

Summary

Introduction

Despite the enormous improvements made in adhesive technology throughout the last 50 years, there are still some unresolved problems regarding the durability of the adhesive interface [1]. Impervious seal between resin and dentin substrate remains difficult to achieve [2], and it is doubtful that an ideal interdiffusion of the adhesive system inside collagen scaffold can be produced in a harmonious fashion [3]. The actual mechanisms of degradation are far from being fully understood. In this sense, it is necessary to strictly characterize the recommendations of each company and to follow them; otherwise, deterioration of the adhesive could occur [6]. Achieving adequate hybridization within collagen fibrils and the stability of resin-dentin interface are of key importance [7]. It is fundamental to recognize that the mechanism of hybridization in which an interdiffusion zone, called: “Hybrid layer”, is created, fulfills the occurrence of the micromechanical retention of the restoration [8]

Objectives

Methods

Results

Conclusion