ABSTRACT
This study evaluated the influence of the prolonged setting time of an ethanol-based adhesive system on the dentin bond strength and degree of conversion. Labial and lingual surfaces of fifteen human third molars were flattened until the dentin was exposed and randomly allocated to 3 groups (n = 10), according to the dwell time between the application of two consecutive layers of the adhesive system (Adper Single Bond Plus, 3M ESPE) and light activation: G1--control (no extra dwell time); G2 and G3--dwell time of 30 seconds and 60 seconds, respectively. After light curing, two cylinders (1.4 x 1 mm) of composite resin (Filtek Flow, 3M ESPE) were bonded to each surface and submitted to micro-shear testing, 24 hours after light curing. A similar adhesive procedure was used for the degree of conversion evaluation using Fourier transform infrared spectroscopy (FTIR). Significant differences between bond strength values (p = 0.0003) and degrees of conversion (p = 0.0004) were detected. The bond strength of G3 (60-second dwell time) was statistically higher than that of other groups. G1 (control) and G2 (30-second dwell time) presented similar results. Values of degree of conversion indicated that both the 30-second and 60-second dwell times resulted in similar and greater percentages of conversion. The use of a longer dwell time (60 seconds) might provide better solvent volatilization and monomer infiltration; bringing benefits to dentin bonding using simplified etch & rinse adhesive systems.
Subject(s)
Dental Bonding , Dentin-Bonding Agents , Solvents , Composite Resins , Ethanol , Humans , In Vitro Techniques , Shear Strength , Time FactorsSubject(s)
Humans , Dental Bonding , Dentin-Bonding Agents , Solvents , Composite Resins , Ethanol , Shear Strength , Time FactorsSubject(s)
Humans , Dental Bonding , Dentin-Bonding Agents , Solvents , Time Factors , Ethanol , Composite Resins , Shear StrengthABSTRACT
This study evaluated the bonding compatibility between dual-cured resin cements and simplified adhesive systems (one-step self-etch and two-step etch & rinse), measured after 24 hours and 3 months. The occlusal dentin surfaces of 24 human third molars were exposed and flattened. Teeth were randomly assigned to 3 groups and treated with different combinations of adhesive system and resin cement [G1-Single Bond/Rely X ARC (SB/RX); G2-Excite DSC/Variolink II (EX/VR); G3-Adper Prompt/Rely X ARC (AD/RX)]. Indirect composite restorations were cemented on flattened surfaces, and sectioned to obtain multiple bonded beams for the microtensile bond strength test. The beams from each tooth were tested under tension after 24 hours and 3 months (ANOVA/ Tukey's test, alpha=5%). Failure patterns were evaluated with scanning electron microscopy. After 24h, AD/RX presented the lowest bond strength mean values. AD/RX specimens did not withstand three months storage. SB/RX and EX/VR presented similar bond strengths in both periods tested. The association AD/RX resulted in low bond strength mean values, especially after storage. Cementing indirect restorations using one-step self-etch adhesive systems and dual-cured resin cements would be clinically unreliable.
Subject(s)
Materials Testing , Resin Cements , Self-Curing of Dental Resins , Dental Cements , Humans , In Vitro Techniques , Time FactorsABSTRACT
This study evaluated the bonding compatibility between dualcuredresin cements and simplified adhesive systems (one-step self-etch and two-step etch & rinse), measured after 24 hours and 3 months. The occlusal dentin surfaces of 24 human third molars were exposed and flattened. Teeth were randomly assigned to 3 groups and treated with different combinations ofadhesive system and resin cement [G1 - Single Bond/Rely X ARC (SB/RX); G2 - Excite DSC/Variolink II (EX/VR); G3 -Adper Prompt/Rely X ARC (AD/RX)]. Indirect composite restorations were cemented on flattened surfaces, and sectioned to obtain multiple bonded beams for the microtensile bond strength test. The beams from each tooth were tested under tension after 24 hours and 3 months (ANOVA/ Tukeys test, α=5%). Failure patterns were evaluated with scanning electron microscopy. After 24h, AD/RX presented the lowest bond strength mean values. AD/RX specimens did not withstandthree months storage. SB/RX and EX/VR presented similar bond strengths in both periods tested. The associationAD/RX resulted in low bond strength mean values, especially after storage. Cementing indirect restorations using one-step self-etch adhesive systems and dual-cured resin cements wouldbe clinically unreliable.
Este estudo avaliou a compatibilidade de união entre cimentos resinosos de dupla polimerização e sistemas adesivos simplificados (adesivo autocondicionante - 1 passo- e adesivo total-each - 2 passos), após 24h e 3 meses. A superfície oclusal de 24 terceiros molares humanos foi exposta e planificada. Os dentes foram aleatoriamente divididos em 3 grupos usados de acordo a seguinte combinação entre sistema adesivo/cimento resinoso [G1 - Single Bond/Rely X ARC (SB/RX); G2 - Excite DSC/Variolink II (EX/VR); G3-Adper Prompt/Rely X ARC (AD/RX)]. Restaurações indiretas em resina composta foram cimentadas na superfície dentinária, e seccionados em múltiplos palitos para a realização do teste de resistência de união através do ensaio de microtração. Os palitos obtidos por dente foram submetidos ao teste após 24 horas e 3 meses (ANOVA/ Tukey test, α=5%). O padrão de fraturafoi observado no microscópio eletrônico de varredura. Após 24 horas, AD/RX apresentou menor valor médio de resistência de união. Os corpos-de-prova do grupo AD/RX não resistiram aoarmazenamento de 3 meses. SB/RX e EX/VR demonstraram similarresistência de união em ambos os períodos avaliados. A associação AD/RX resultou em menores valores médios deresistência de união, especialmente após o armazenamento. A cimentação de restaurações indiretas utilizando sistemas autocondicionantes (1 passo) e cimentos resinosos de dupla polimerização não foi considerada clinicamente confiável.
Subject(s)
Dentin-Bonding Agents/chemistry , Resin Cements/chemistry , Dentin , Dental Bonding/methods , Compressive Strength , Microscopy, Electron, Scanning/methods , Data Interpretation, StatisticalABSTRACT
This study evaluated the bonding compatibility between dualcuredresin cements and simplified adhesive systems (one-step self-etch and two-step etch & rinse), measured after 24 hours and 3 months. The occlusal dentin surfaces of 24 human third molars were exposed and flattened. Teeth were randomly assigned to 3 groups and treated with different combinations ofadhesive system and resin cement [G1 - Single Bond/Rely X ARC (SB/RX); G2 - Excite DSC/Variolink II (EX/VR); G3 -Adper Prompt/Rely X ARC (AD/RX)]. Indirect composite restorations were cemented on flattened surfaces, and sectioned to obtain multiple bonded beams for the microtensile bond strength test. The beams from each tooth were tested under tension after 24 hours and 3 months (ANOVA/ Tukeys test, α=5%). Failure patterns were evaluated with scanning electron microscopy. After 24h, AD/RX presented the lowest bond strength mean values. AD/RX specimens did not withstandthree months storage. SB/RX and EX/VR presented similar bond strengths in both periods tested. The associationAD/RX resulted in low bond strength mean values, especially after storage. Cementing indirect restorations using one-step self-etch adhesive systems and dual-cured resin cements wouldbe clinically unreliable.(AU)
Este estudo avaliou a compatibilidade de uniÒo entre cimentos resinosos de dupla polimerizaþÒo e sistemas adesivos simplificados (adesivo autocondicionante - 1 passo- e adesivo total-each - 2 passos), após 24h e 3 meses. A superfície oclusal de 24 terceiros molares humanos foi exposta e planificada. Os dentes foram aleatoriamente divididos em 3 grupos usados de acordo a seguinte combinaþÒo entre sistema adesivo/cimento resinoso [G1 - Single Bond/Rely X ARC (SB/RX); G2 - Excite DSC/Variolink II (EX/VR); G3-Adper Prompt/Rely X ARC (AD/RX)]. Restauraþ§es indiretas em resina composta foram cimentadas na superfície dentinária, e seccionados em múltiplos palitos para a realizaþÒo do teste de resistÛncia de uniÒo através do ensaio de microtraþÒo. Os palitos obtidos por dente foram submetidos ao teste após 24 horas e 3 meses (ANOVA/ Tukey test, α=5%). O padrÒo de fraturafoi observado no microscópio eletr¶nico de varredura. Após 24 horas, AD/RX apresentou menor valor médio de resistÛncia de uniÒo. Os corpos-de-prova do grupo AD/RX nÒo resistiram aoarmazenamento de 3 meses. SB/RX e EX/VR demonstraram similarresistÛncia de uniÒo em ambos os períodos avaliados. A associaþÒo AD/RX resultou em menores valores médios deresistÛncia de uniÒo, especialmente após o armazenamento. A cimentaþÒo de restauraþ§es indiretas utilizando sistemas autocondicionantes (1 passo) e cimentos resinosos de dupla polimerizaþÒo nÒo foi considerada clinicamente confiável.(AU)
