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Brazilian Oral Research 2015This study aimed to identify factors that can affect the retention of glass fiber posts to intra-radicular dentin based on in vitro studies that compared the bond... (Review)
Review
This study aimed to identify factors that can affect the retention of glass fiber posts to intra-radicular dentin based on in vitro studies that compared the bond strength (BS) of GFPs cemented with resin cements. Searches were carried out in PubMed and Scopus until December 2013. Bond strength values and variables as type of tooth, presence of endodontic treatment, pretreatment of the post, type of bonding agent (if present), type of cement and mode of cement application were extracted from the 34 included studies. A linear regression model was used to evaluate the influence of these parameters on BS. The presence of endodontic treatment decreased the BS values in 22.7% considering the pooled data (p = 0.013). For regular cement, cleaning the post increased BS when compared to silane application without cleaning (p = 0.032), considering cleaning as ethanol, air abrasion, or phosphoric acid application. Applying the cement around the post and into root canal decreased the resistance compared to only around the post (p = 0.02) or only into root canal (p = 0.041), on the other hand, no difference was found for self-adhesive resin cement for the same comparisons (p = 0.858 and p = 0.067). Endodontic treatment, method of cement application, and post pretreatment are factors that might significantly affect the retention of glass-fiber posts into root canals mainly when cemented with regular resin cement. Self-adhesive resin cements were found to be less technique-sensitive to luting procedures as compared with regular resin cements.
Topics: Analysis of Variance; Animals; Cattle; Cementation; Dental Prosthesis Retention; Dentin Desensitizing Agents; Glass; Humans; Post and Core Technique; Resin Cements; Treatment Outcome
PubMed: 26083089
DOI: 10.1590/1807-3107BOR-2015.vol29.0074 -
Australian Dental Journal Sep 2015Carious affected dentine (CAD) represents a very common substrate in adhesive dentistry. Despite its ability to interact with adhesive systems, the intrinsic character... (Review)
Review
BACKGROUND
Carious affected dentine (CAD) represents a very common substrate in adhesive dentistry. Despite its ability to interact with adhesive systems, the intrinsic character of CAD leads to lower bonding compared with sound dentine, regardless of the adhesive systems used. This low bonding may be more susceptible to leakage and hydrolysis of the interface by matrix metalloproteinases (MMPs). This systematic review aimed to determine current knowledge of CAD bonding, together with bond strength and MMP inhibitors' ability to prevent hybrid layer instability.
METHODS
MEDLINE/Pubmed, Scopus and The Cochrane Library databases were electronically searched for articles published from 1 January 1960 to 31 August 2014. Two reviewers independently screened and included papers according to predefined selection criteria.
RESULTS
The electronic searches identified 320 studies. After title, abstract and full-text examinations, 139 articles met the inclusion criteria. Data highlighted that a poor resin saturation of the already demineralized collagen matrix in CAD is strictly related to nanoleakage in interdiffusion and is the basis of the progressive decrease in strength with hydrolysis by MMPs. The use of mild self-etching systems seems to be the more accredited method to establish bonding in CAD. Inhibitors of MMPs may ensure better performance of CAD bonding, allowing undisturbed remineralization of the affected matrix.
CONCLUSIONS
CAD bonding needs further understanding and improvement, particularly to enhance the strength and durability of the hybrid layer.
Topics: Dental Bonding; Dental Caries; Dental Cements; Dental Leakage; Dentin; Humans; Matrix Metalloproteinase Inhibitors; Stress, Mechanical
PubMed: 25790344
DOI: 10.1111/adj.12309 -
Experimental and Therapeutic Medicine Oct 2014The aim of the present study was to compare the root canal preparation ability of rotary nickel-titanium (NiTi) Hero 642 and K3 files in curved mandibular or maxillary...
The aim of the present study was to compare the root canal preparation ability of rotary nickel-titanium (NiTi) Hero 642 and K3 files in curved mandibular or maxillary molars. A total of 40 extracted mandibular molars with two separate mesial canals, an apical width of approximately size ≤15 and a root canal curvature of 15-30° were randomly divided into two groups and instrumented using Hero 642 (n=20) or K3 files (n=20). Canal straightening, working length, transportation, cross-sectional area, minimum dentin thickness and the canal angle curvature degree were examined, and a systematic review of the literature was conducted. No statistically significant differences were observed between the two groups with regard to the mean degree of straightening, mean change in working length, mean transportation, amount of dentin removed or remaining minimum dentin thickness (P>0.05). The canal angle curvature decreased in the two groups postoperatively. The systematic review identified six studies, and overall the two files performed similarly in the majority of categories examined. Therefore, the rotary NiTi Hero 642 and K3 files demonstrated comparable shaping abilities and maintenance of working length.
PubMed: 25187795
DOI: 10.3892/etm.2014.1853