OBJECTIVES: This study evaluated how deproteinization using sodium hypochlorite (6% NaOCl) or hypochlorous acid (50 ppm HOCl) with or without the subsequent use of an arylsulfinate salt-containing agent (Clearfil DC Activator; DCA; Kuraray Noritake Dental) affects the micro-tensile bond strength (μTBS) and formation of an acid-base resistant zone (ABRZ) of a two-step self-etch adhesive on eroded dentin. METHODS: Coronal dentin surfaces of sound human molars were exposed to 48 cycles of demineralization (1% citric acid; 5 minutes) and remineralization (buffer solution with pH=6.4; 3.5 hours). They were then assigned to experimental groups according to the pretreatment used: none (negative control), NaOCl, NaOCl+DCA, HOCl, and HOCl+DCA. Sound dentin surfaces with no pretreatment were used as a positive control. The dentin surfaces were bonded with Clearfil SE Bond 2 (Kuraray Noritake Dental), and μTBS was measured either after 24 hours or 20,000 thermal cycles (TC). The μTBS data were statistically analyzed using a mixed-model analysis of variance (ANOVA) and t-tests with Bonferroni correction. Failure mode was determined with scanning electron microscopy (SEM), which was also used for the observation of ABRZ. RESULTS: Among experimental groups, there was no significant difference between the negative control, HOCl, and HOCl+DCA after 24 hours, but the HOCl-pretreated groups exhibited significantly higher μTBS than the negative control after TC (p<0.01). Pretreatment with NaOCl and NaOCl+DCA resulted in significantly higher μTBS (p<0.001), but the highest μTBS was measured on sound dentin (p<0.001). TC decreased μTBS significantly in all groups (p<0.001) except for sound dentin and NaOCl+DCA (p>0.05). Adhesive failures prevailed in eroded groups, whereas cohesive failures were predominant on sound dentin. ABRZ was recognized in all groups but marked morphological differences were observed. CONCLUSIONS: The combined use of 6% NaOCl and the arylsulfinate salt-containing agent partially reversed the compromised bonding performance on eroded dentin, while the effect of 50 ppm HOCl was negligible.
- MeSH
- Dentin MeSH
- Dentin-Bonding Agents pharmacology chemistry MeSH
- Humans MeSH
- Tensile Strength MeSH
- Resin Cements pharmacology chemistry MeSH
- Materials Testing MeSH
- Dental Bonding * methods MeSH
- Dental Cements * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
PURPOSE: To estimate the in vitro reliability of typical self-etching and etch-and-rinse adhesives of various application protocols.
- MeSH
- Acrylic Resins chemistry MeSH
- Bisphenol A-Glycidyl Methacrylate chemistry MeSH
- Time Factors MeSH
- Dentin ultrastructure MeSH
- Dentin-Bonding Agents chemistry MeSH
- Financing, Organized MeSH
- Polymethacrylic Acids chemistry MeSH
- Acid Etching, Dental MeSH
- Humans MeSH
- Stress, Mechanical MeSH
- Methacrylates chemistry MeSH
- Organophosphates chemistry MeSH
- Shear Strength MeSH
- Probability MeSH
- Resin Cements chemistry MeSH
- Composite Resins chemistry MeSH
- Temperature MeSH
- Materials Testing MeSH
- Dental Bonding MeSH
- Water chemistry MeSH
- Check Tag
- Humans MeSH
OBJECTIVES: To evaluate the sealing performance of self-etch adhesives (SEA) after smear layer deproteinization with chemo-mechanical caries removal agents (CRA) to enamel and dentin cavity walls in comparison with 6% NaOCl smear layer deproteinizing. METHODS: Eighty extracted bovine incisors with tapered cylindrical cavities (2.5 mm upper diameter, 1.5 mm lower diameter, 2 mm depth) at the cemento-enamel junction were randomly divided into four pre-treatment groups; no treatment (control), Papacarie (papain enzyme-based CRA), Carisolv (NaOCl-based CRA), and 6% NaOCl. After pretreatment, G-Bond Plus (GBP, one-step SEA) or Clearfil SE Bond 2 (CSE, two-step SEA) was applied to the pre-treated cavity, and then filled with a flowable resin composite (Clearfil Majesty ES Flow). Gap formations at the enamel and dentin lateral walls, and on the dentin cavity floor were investigated using swept-source optical coherence tomography (SS-OCT) after 24-h water storage at 37 °C. Deproteinizing effects of the tested agents on smear layer-covered enamel and dentin were quantified by changes in the amide:phosphate ratio using ATR-FTIR analysis. RESULTS: Papacarie significantly reduced gap formation with both self-etch adhesives at all locations, compared to the control group (p < 0.05). In contrast, increased gap formation was observed with Carisolv and NaOCl. In most groups, CSE exhibited significantly lower gap formation than GBP (p < 0.05). ATR-FTIR revealed a significant decrease in the amide:phosphate ratio for all the deproteinizing agents (p < 0.05). CONCLUSIONS: Chemo-mechanical CRAs could effectively remove the organic phase of enamel and dentin smear layer. The papain enzyme-based gel Papacarie could improve the sealing performance of the self-etch adhesives to both enamel and dentin.
- MeSH
- Adhesives MeSH
- Dentin MeSH
- Dentin-Bonding Agents MeSH
- Resin Cements MeSH
- Cattle MeSH
- Composite Resins MeSH
- Smear Layer * MeSH
- Materials Testing MeSH
- Dental Bonding * MeSH
- Dental Cements MeSH
- Dental Enamel MeSH
- Animals MeSH
- Check Tag
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The effect of different air-blowing strategies using a prototype of a newly developed clinically applicable warm air-blowing device on the microtensile bond strength (μTBS) of one-step self-etch adhesives (1-SEAs) to human root-canal dentin was evaluated. Post cavities (8 mm depth, 1.5 mm diameter) were prepared and bonded with four 1-SEAs. Air-blowing was performed using normal air (23±1°C) for 10 or 20 s; warm air (60±1°C) for 10 or 20 s; or their combination for 10 s (5 s normal, 5 s warm) or 20 s (10 s normal, 10 s warm). After filling with corresponding core materials and 24-h water storage, μTBS test was performed. For three of the 1-SEAs, combined air-blowing for 20 s significantly increased μTBS compared to other air-blowing strategies (p<0.05). This suggests that the combination of normal and warm air-blowing for 20 s can enhance solvent evaporation from 1-SEAs, thus resulting in their improved bonding performance to root-canal dentin.
- MeSH
- Adhesives MeSH
- Dentin MeSH
- Dentin-Bonding Agents MeSH
- Dental Pulp Cavity MeSH
- Humans MeSH
- Tensile Strength MeSH
- Resin Cements MeSH
- Materials Testing MeSH
- Dental Bonding * MeSH
- Dental Cements MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Statement of problem: It has been shown that selective etching improves the bond strength of some self-adhesive resin cements to enamel. The same has yet to be determined with dentin pre-treatment. Purpose: To evaluate the tensile bond strength of two self-adhesive resin cements after two dentin surface pre-treatments, and also to analyze the cement/dentin interface. Material and Methods: One hundred and twelve human third molars were extracted. The teeth were distributed into seven groups (n = 16). Maxcem Elite Chroma (MAX) (Kerr, Scafati, Italy) and Relyx U200 (RLX) (3M ESPE, Neuss, Germany) were used without pre-treatment or with two dentin pre-treatments (polyacrylic acid or phosphoric acid). A conventional etch-and-rinse (EAR) luting cement, NX3 Nexus (NX3) (Kerr, Scafati, Italy), was used as an external control group. Before testing, all specimens were stored in distilled water for 24 hours. Three specimens from each group were prepared for scanning electron microscopy observation (SEM). A tensile bond strength test (TBS) was performed for the remaining samples. The data were statistically analyzed using the Kruskal-Wallis test and Pairwise comparisons using the Wilcoxon rank sum test. Results: MAX without pre-treatment and with phosphoric acid etching attained statistically similar bond strengths to NX3 (P > 0.05). There was a statistical difference (P = 0.00488) between RLX without pre-treatment (5.62 MPa) and NX3 (10.88 MPa). Phosphoric acid pre-treatment increases the bond strength values of RLX to a strength that is comparable to NX3 (P > 0.05). The lowest tensile bond strength (TBS) was attained after the application of polyacrylic acid with MAX (1.98 MPa). No statistical differences were found between the RLX bond strength values after polyacrylic acid treatment and RLX without pre-treatment or NX3 (P > 0.05). SEM observations disclosed an enhanced potential of the self-adhesive cements to infiltrate into dentin tubules and form resin tags when applied after phosphoric acid pre-treatment. The failure mode was dominantly adhesive. Conclusions: On dentin, the self-adhesive resin cement MAX might be an effective alternative to conventional resin cement. Etching the dentin with phosphoric acid does not have a negative effect on the bond strength of MAX to dentin. On the other hand, phosphoric acid improved the bond strength of RLX when compared to EAR cement.
- Publication type
- Journal Article MeSH
OBJECTIVE: The influence of light-curing of a one-step self-etch adhesive (1-SEA) prior to the application of different bonding agents (BA) on the micro-tensile bond strength (μTBS) to dentin after 24h and thermal cycling was investigated. Additionally, the degree of conversion was evaluated using Fourier-transform infrared spectroscopy. METHODS: Three ion-releasing BAs, BZF-21 (experimental BA), Clearfil SE Protect (CSP), and FL-Bond II (FL-II), were applied subsequently to G-Premio Bond (1-SEA, GPB). Prior to their application, GPB was either light-cured (10s, 1000mW/cm2) or remained uncured. GPB was used as a control and Clearfil SE Bond 2 (CSE2) as a gold-standard 2-step reference. After resin-composite build-up and 24-h water storage (24h), half of the specimens were subjected to 15,000 thermal cycles (TC). Then, the specimens were sectioned into beams and tested under tensile load (1mm/min). The acquired data were analyzed using a 2-way ANOVA and Student's t-test with Bonferroni correction, and a two-parameter Weibull analysis, α=0.05. RESULTS: The μTBS of GPB increased significantly in the uncured groups with BZF-21 (24h: p<0.001, TC: p<0.001) and CSP (24h: p=0.039, TC: p<0.001), and in the light-cured group with CSP after TC (p=0.044). The groups with FL-II were not significantly different from GPB (p=1). No significant difference was found between CSE2 and the uncured groups GPB+BZF-21 (24h: p=1, TC: p=0.452) and GPB+CSP (24h: p=0.671, TC: p=0.566). SIGNIFICANCE: BZF-21 and CSP improved the μTBS of GPB to dentin both immediately and after TC. Higher μTBSs were obtained when GPB remained uncured prior to BA application.
- MeSH
- Dentin MeSH
- Dentin-Bonding Agents MeSH
- Humans MeSH
- Tensile Strength MeSH
- Resin Cements MeSH
- Composite Resins MeSH
- Curing Lights, Dental * MeSH
- Materials Testing MeSH
- Dental Bonding * MeSH
- Dental Cements MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Na souboru devíti total-etch a self-etching adhezivních systémů zahrnujících OptiBond FL, Gluma Comfort Bond, Prime & Bond NT, AdheSE, Adper Prompt, Adper Prompt L-Pop, Clearfil SE Bond, Xeno III a iBond byla testována pevnost vazby ve smyku na dentinu a fraktografie lomových ploch řádkovací elektronovou mikroskopií. Adheziva byla hodnocena podle kritické pevnosti vazby, při které dojde k lomu 10 % vzorků. Ve shodě s výsledky fraktografické analýzy byly nalezeny významné rozdíly jak mezi skupinami total a self-etching adheziv, tak mezi adhezivy v těchto skupinách. Nejvyšší spolehlivost a převážně smíšené energeticky náročné lomy, zasahující do dentinu, byly nalezeny u skupiny klasických 3 a 2krokových total-etch systémů OptiBond FL a Gluma Comfort Bond, ale i u self-etching systémů AdheSE a Clearfil SE Bond. U těchto systémů lze s vysokou pravděpodobností očekávat vysokou pevnost vazby a reprodukovatelné chování. U skupiny Adper Promt, iBond a Xeno III s kohezním lomem adheziva, či smíšenými lomy byla spolehlivost nižší. Pro dosažení dobré adheze je při jejich aplikaci nutné pečlivě dodržovat pracovní postup. Na druhou stranu adheziva Prime & Bond NT a zejména Adper Prompt L-Pop v blistrech s adhezním porušením na rozhraní dentinu a adheziva vynikaly nízkou pevností vazby a nízkou spolehlivostí. U self-etching adheziv může jejich vlastnosti velmi negativně ovlivnit i stárnutí během skladování, zejména při nedodržení doporučených podmínek skladování.
A shear bond strength and fractography analysis was used to evaluate reliability of nine total- and self-etching adhesives OptiBond FL, Gluma Comfort Bond, Prime&Bond NT, AdheSE, Adper Prompt, Adper Prompt L-Pop, Clearfil SE Bond, Xeno III and iBond. A critical bond strength at which 10 % samples failed was used as a measure of the adhesive reliability. Significant differences in reliability and also in mode of their fracture were found between total- and self-etching systems and also in adhesives in these groups. The highest reliability and mixed mode of fracture were found with group of classical total-etch 3- and 2-step adhesives OptiBond FL a Gluma Comfort Bond and also with 2-step self-etching AdheSE and Clearfil SE Bond. With these adhesives both high bond strength and highly predictable properties can be expected. Compromised reliability as manifested in decreased bond strength and predominantly less energetically demanding cohesive fractures of the adhesive layer or less frequently mixed fractures occurred for Adper Promt, iBond a Xeno III. On the other hand, Prime & Bond NT and especially Adper Prompt L-Pop in blisters were characterized as systems with a low reliability. Adhesive properties of self-etching systems might decrease as a result of aging processes during their shelf-life.
This study investigated the influence of application/wash-out times of sodium hypochlorite (NaOCl) and hypochlorous acid (HOCl) on dentin bond strength of one-step self-etch adhesives (1-SEAs). Human coronal dentin discs with a standardized smear layer were pretreated with 6% NaOCl or 100 ppm HOCl for 5 s, 15 s, or 30 s, and washed out with water for 5 s, 15 s or 30 s with or without the application of Clearfil DC Activator (CDA). No pretreatment was used as a control. The discs were bonded with a 1-SEA (Bond Force II or Clearfil Universal Bond Quick) and microtensile bond strength (μTBS) was measured after 24 h. Pretreatment with NaOCl for 15 s and 30 s significantly decreased μTBS (p<0.05), irrespective of wash-out time. The application of CDA recovered μTBS but did not outperform the control group. Conversely, pretreatment with HOCl for 15 s and 30 s followed by 30 s wash-out time significantly increased μTBS of 1-SEAs (p<0.05), regardless of CDA application.
- MeSH
- Dentin chemistry MeSH
- Dentin-Bonding Agents chemistry MeSH
- Hypochlorous Acid analysis MeSH
- Humans MeSH
- Tensile Strength MeSH
- Resin Cements chemistry MeSH
- Smear Layer * MeSH
- Materials Testing MeSH
- Dental Bonding * MeSH
- Dental Cements MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
