The objective of this research is to evaluate the effects of different silane coupling agents on the bond strength between Ceramco3 opaque porcelain and indirect composite resin. Five groups of Co-Cr metal alloy substrates were fabricated according to manufacturer's instruction. The surface of metal alloy with a layer of dental opaque porcelain was heated by fire. After the surface of opaque porcelain was etched, five different surface treatments, i.e. RelyX Ceramic Primer (RCP), Porcelain Bond Activator and SE Bond Primer (mixed with a proportion of 1:1) (PBA), Shofu Porcelain Primer (SPP), SE bond primer (SEP), and no primer treatment (as a control group), were used to combine P60 and opaque porcelain along with resin cement. Shear bond strength of specimens was tested in a universal testing machine. The failure modes of specimens in all groups were observed and classified into four types. Selected specimens were subjected to scanning electron microscope and energy disperse spectroscopy to reveal the relief of the fracture surface and to confirm the failure mode of different types. The experimental results showed that the values of the tested items in all the tested groups were higher than that in the control group. Group PBA exhibited the highest value[(37.52±2.14) MPa] and this suggested a fact that all of the specimens in group PBA revealed combined failures (failure occurred in metal-porcelain combined surface and within opaque porcelain). Group SPP and RCP showed higher values than SEP (P<0.05) and most specimens of SPP and RCP performed combined failures (failure occurred in bond surface and within opaque porcelain or composite resin) while all the specimens in group SEP and control group revealed adhesive failures. Conclusions could be drawn that silane coupling agents could reinforce the bond strength of dental composite resin to metal-opaque porcelain substrate. The bond strength between dental composite resin and dental opaque porcelain could meet the clinical requirements.
Dental composite resin is a kind of material which has been widely used in dental restoration. Research has found that the influence of residual monomer on the material mechanical, chemical and biological properties cannot be ignored. This paper elaborates these harms of residual monomers. The effects of resin matrix, inorganic filler and initiating system, illumination, secondarily treatment on the degree of conversion were also analyzed. The paper also discusses the effective measures to increase the conversion, and offers theoretical basis for the clinical application and development of composite resin.
Objective To evaluate the efficacy of light cured composite resin and glass ionomer cement for wedge shaped defect filling. Methods PubMed, The Cochrane Library (Issue 3, 2016), EMbase, CNKI, CBM, VIP and WanFang Data were searched from inception to April 5th 2016, to collect randomized controlled trials (RCTs) of light cured composite resin versus glass ionomer cement for wedge shaped defect filling. According to the inclusion and exclusion criteria, two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by RevMan 5.2 software. Results A total of 12 studies, involving 3 744 cases of teeth were included. Meta-analysis results showed that there was no significant difference in the two groups on the shedding rate after 2 years (OR=1.19, 95%CI 0.70 to 2.02,P=0.53). But the wear rate of the light cured composite resin group was significantly lower than that of the glass ionomer cement group (Peto OR=0.31, 95%CI 0.22 to 0.44,P<0.000 01). The light cured composite resin group had higher rate of micro leakage or secondary caries rate (OR=1.83, 95%CI 1.11 to 3.01,P=0.02) and incidence of endodontic or periapical lesions (Peto OR=2.84, 95%CI 1.82 to 4.45,P<0.000 01) than the glass ionomer cement group. Conclusion Glass ionomer cement for filling wedge-shaped defects of 2 years after the wear degree is higher than the light cured composite resin, but the occurrence probability of micro leakage or secondary caries and stimulation to pulp are lower than the light cured composite resin. Because of the limitations of the quality of the included studies, the above conclusion still needs to be verified by more high-quality studies.
Objective To evaluate the efficacy of the light cured flowable composite resin and the light cured pit and fissure sealant in the prevention of dental caries in children. Methods EMbase, CBM, The Cochrane Library, PubMed, Web of Science, CNKI, WanFang Data and VIP databases were searched from inception to January 1st, 2017 for randomized controlled trials (RCTs) or quasi-RCTs about the application of the light cured flowable composite resin and the light cured pit and fissure sealants. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, the RevMan 5.3 software was applied to conduct meta-analysis. Results A total of 13 studies were included. The results of meta-analysis showed that the complete retention rate of the light cured flowable composite resin group was higher than that of the light cured pit and fissure sealant group (6 months: RR=1.03, 95%CI 1.00 to 1.06, P=0.03; 12 months: RR=1.09, 95%CI 1.04 to 1.13, P=0.000 3; 24 months: RR=1.22, 95%CI 1.13 to 1.31, P<0.000 01). The incidence of caries of the light cured flowable composite resin group was lower than that of the light cured pit and fissure sealant group (12 months: Peto OR=0.30, 95%CI 0.16 to 0.56,P=0.000 2; 24 months: Peto OR=0.44, 95%CI 0.31 to 0.63, P<0.000 01). Conclusion The light cured flowable composite resin is superior to the light cured pit and fissure sealant in the complete retention and caries prevention. The above conclusions are needed to be verified by more high-quality clinical studies because of the limitation of the quality and follow-up time of studies.