The effect of chlorhexidine and dimethyl sulfoxide on long-term sealing ability of two calcium silicate cements in root canal

Objectives. To evaluate the long-term effect of chlorhexidine (CHX) and dimethyl sulfoxide (DMSO) on the sealing ability and biomineralization of two different calcium silicate cements (CSC) in root canal. Methods. Sixty human third molar root canals were obturated with ProRoot MTA or Biodentine. Before obturation the canals were irrigated with saline (control), 2% CHX or 5% DMSO. Microleakage was tested after three days and after six months. After additional six months (12 months after root filling) the roots were cut into 2 mm thick dentine discs. The discs were stored in artificial saliva for one year. The bond strength was measured with the push-out method, and the failure mode was evaluated with a stereomicroscope. The most apical disc of each tooth was used for Vickers hardness test. Results. No significant differences between the groups was found in initial microleakage. The leakage increased significantly during the 6-month storage in all groups except in Biodentine-CHX group and Biodentine-DMSO group. CHX and DMSO irrigation significantly increased the leakage with ProRoot MTA with time, but there was no statistically significant difference compared to the ProRoot MTA-control group at six months' time point. CHX significantly reduced the push-out bond strength of ProRoot MTA. With Biodentine irrigation with CHX or DMSO resulted with significantly higher push-out strength compared to the Biodentine control group. Fracture analysis showed statistically significant difference in the distribution of the fractures between the groups, but neither CHX nor DMSO change the fracture pattern statistically significantly. With Vickers hardness test ProRoot MTA with and without DMSO as the final irrigant showed significantly higher dentin hardness than any Biodentine-group. Significance. Considering that aging increased the leakage in all groups except with Biodentine-DMSO and the differences in the push-out strength and surface microhardness data, it appears that the time-related biomineralizing effect of MTA and Biodentine does not improve sealing to dentin. CHX significantly reduced ProRoot MTA bond strength and increased pure adhesive failures with both cements. (C) 2020 Published by Elsevier Inc. on behalf of The Academy of Dental Materials.Peer reviewe

The effect of chlorhexidine and dimethyl sulfoxide on long-term sealing ability of two calcium silicate cements in root canal

Objectives. To evaluate the long-term effect of chlorhexidine (CHX) and dimethyl sulfoxide (DMSO) on the sealing ability and biomineralization of two different calcium silicate cements (CSC) in root canal. Methods. Sixty human third molar root canals were obturated with ProRoot MTA or Biodentine. Before obturation the canals were irrigated with saline (control), 2% CHX or 5% DMSO. Microleakage was tested after three days and after six months. After additional six months (12 months after root filling) the roots were cut into 2 mm thick dentine discs. The discs were stored in artificial saliva for one year. The bond strength was measured with the push-out method, and the failure mode was evaluated with a stereomicroscope. The most apical disc of each tooth was used for Vickers hardness test. Results. No significant differences between the groups was found in initial microleakage. The leakage increased significantly during the 6-month storage in all groups except in Biodentine-CHX group and Biodentine-DMSO group. CHX and DMSO irrigation significantly increased the leakage with ProRoot MTA with time, but there was no statistically significant difference compared to the ProRoot MTA-control group at six months' time point. CHX significantly reduced the push-out bond strength of ProRoot MTA. With Biodentine irrigation with CHX or DMSO resulted with significantly higher push-out strength compared to the Biodentine control group. Fracture analysis showed statistically significant difference in the distribution of the fractures between the groups, but neither CHX nor DMSO change the fracture pattern statistically significantly. With Vickers hardness test ProRoot MTA with and without DMSO as the final irrigant showed significantly higher dentin hardness than any Biodentine-group. Significance. Considering that aging increased the leakage in all groups except with Biodentine-DMSO and the differences in the push-out strength and surface microhardness data, it appears that the time-related biomineralizing effect of MTA and Biodentine does not improve sealing to dentin. CHX significantly reduced ProRoot MTA bond strength and increased pure adhesive failures with both cements. (C) 2020 Published by Elsevier Inc. on behalf of The Academy of Dental Materials.Peer reviewe

Association between dental factors and mortality

Peer reviewe

A novel dry-bonding approach to reduce collagen degradation and optimize resin-dentin interfaces

In dentistry, the wet-bonding approach relies on water to maintain demineralized collagen expanded for proper resin infiltration; nevertheless, hydrolytic instability of the resin-dentin interface is inevitable with current bonding techniques. Considering dimethyl sulfoxide’s (DMSO) ability to “biomodify” collagen and precipitate enzymes, the aim was to test whether the use of DMSO would permit adequate resin bonding to H3PO4-etched dehydrated dentin and assess its impact on collagen degradation by host-derived enzymes. Etched dentin surfaces from extracted sound human molars were randomly bonded in wet or dry conditions using aqueous or ethanolic DMSO solutions as pretreatments and bonding resins with or without DMSO. Bonded teeth were sectioned into resin-dentin slabs for confocal in situzymography and beams for microtensile bond strength test. Demineralized powdered dentin was incubated in the tested DMSO -media and a hydroxyproline assay evaluated dissolution of collagen peptides. Zymography was performed on protein extracts obtained from dry and wet H3PO4-ecthed dentin powder treated with the DMSO- media. The correlative biochemical analysis demonstrated that reduction of water content during dentin hybridization by the innovative dry-bonding approaches with DMSO is effective to inactivate host-derived MMP-2 and MMP-9 and thus reduce collagen degradation while simultaneously optimizing resin-dentin bonding.</p

Endodontic management of traumatized permanent teeth : a comprehensive review

The pulp plays a key role in the treatment of traumatic dental injuries (TDIs) and is strongly associated with the outcome, particularly in severe cases. A correct pulp diagnosis is essential as it forms the basis for developing the appropriate management strategy. However, many TDIs are complex, and their treatment requires a profound knowledge of the physiological and pathological responses of the affected tissues. This comprehensive review will look at the dentine-pulp complex and its interaction with the surrounding tissues following TDIs. The literature up to 2020 was reviewed based on several searches on PubMed and the Cochrane Library using relevant terms. In addition to the recently revised guidelines of the International Association of Dental Traumatology, this article aims to provide background information with a focus on endodontic aspects and to gather evidence on which a clinician can make decisions on the choice of the appropriate endodontic approach for traumatized permanent teeth.Peer reviewe

Gene expression of bacterial collagenolytic proteases in root caries

Objective: It is unknown whether bacteria play a role in the collagen matrix degradation that occurs during caries progression. Our aim was to characterize the expression level of genes involved in bacterial collagenolytic proteases in root biofilms with and without caries. Method: we collected samples from active cavitated root caries lesions (RC, n = 30) and from sound root surfaces (SRS, n = 10). Total microbial RNA was isolated and cDNA sequenced on the Illumina Hi-Seq2500. Reads were mapped to 162 oral bacterial reference genomes. Genes encoding putative bacterial collagenolytic proteases were identified. Normalization and differential expression analysis was performed on all metatranscriptomes (FDR8) but none in SRS were Pseudoramibacter alactolyticus [HMPREF0721_RS02020; HMPREF0721_RS04640], Scardovia inopinata [SCIP_RS02440] and Olsenella uli DSM7084 [OLSU_RS02990]. Conclusion: Our findings suggest that the U32 proteases may be related to carious dentine. The contribution of a small number of species to dentine degradation should be further investigated. These proteases may have potential in future biotechnological and medical applications, serving as targets for the development of therapeutic agents