Shear Bond Strength of a Multi-Mode Adhesive to Bur-Cut and Er,Cr:YSGG Lased Dentin in Different Output Powers

Effects of Er: YAG, Er,Cr: YSGG, and Nd: YAG laser irradiation and adhesive systems on the immediate and long-term bond strength of dentin: a systematic review and meta-analysis

At present, lasers are increasingly used in the oral clinical field, and research and applications in dental hard tissue treatment are also increasing. The effect of laser etching dentin on the bonding strength of composite resin reported in the literature is still inconclusive. The purpose of this review was to evaluate whether laser etching can improve the immediate and long-term bonding strength of dentin and investigate the effect of different types of adhesives on the bonding strength of dentin. Two reviewers performed a literature search up from January 2012 to November 2021 in four databases: MEDLINE (PubMed), Web of Science, EMBASE, and the Cochrane Library. A total of 25 studies were included in the meta-analysis. The Cochrane Collaboration Bias Risk Assessment tool was used to evaluate the quality of the included literature, and an analysis was carried out using Review Manager Software version 5.3. The aging bond strength of dentin after erbium (Er): yttrium aluminum garnet (YAG) laser treatment was significantly lower than that of dentin in the bur group (P < 0.00001). At the same time, the bond strength of dentin immediately and aging after (Er), chromium-doped (Cr): yttrium scandium gallium garnet (YSGG) laser treatment was lower than that of dentin in the bur group (P < 0.05). There was no significant difference in the immediate and aging bonding strength among samples in the Er: YAG laser, Er, Cr: YSGG laser, and blank control groups (no laser or bur). The aging bond strength of samples after neodymium-doped (Nd): YAG laser treatment was higher than that of samples in the blank control group (P < 0.05); in addition, the performance of self-etching adhesive was slightly better than that of acid etching adhesive. Regardless of the applied surface treatment and the adhesive employed, dentin after aging showed significant bond degradation (P < 0.05). There was high heterogeneity of bond strength between different groups, and the small number of studies and the contradictory results may be the main reasons for this outcome.

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

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.