The morphology of the resin-tooth interface differs depending on the kind of bonding system used. In this study, two kinds of bonding system, two-step self-etching primer system (OptiBond Solo Plus^TM: OS) and one-bottle onestep system (OptiBond All-In-One^®: OA) by Sybron Dental, both containing similar monomer components, were used for observing the resin-tooth interface.
Enamel, intact dentin surfaces and caries-affected dentin cavities of freshly extracted human molars were prepared for the bonded specimens by the routine technique, and each resin-tooth interface was observed under FESEM after Ar-ion beam etching.
As a result, the resin-tooth junction of both systems was very tight, but the decalcifying effect of the two systems was obviously different. The hybrid layer of OS was clearly observed with a thickness of approximately 1μm, while OA created a thinner decalcified layer of 0.2-0.3μm. We assume that the unique ternary solvent system of OA adhesive may provide effective tooth treatment and achieve high bonding efficacy.

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Radiotherapy for oral cancer causes radiation caries. However, the effect of radiotherapy on dentin is not well understood. Irradiation damage to collagen may adversely affect the adaptation of resin composite to the cavity wall. The purpose of this study was to evaluate the effect of γ-ray irradiation on the marginal sealing and cavity wall adaptation of composite restorations using a one-step adhesive system. One group of bovine incisors was irradiated with 60 Gy γ-rays using a cobalt60therapeutic machine. Cylindrical cavities, 1.5mm deep and3mm in diameter (C-factor=3) were prepared on flat bovine dentin surfaces. The teeth were restored with Clearfil Mega Bond (Kuraray Medical), a one-step bonding system Tokuyama Bond Force (Tokuyama Dental), or Clearfil tri-S Bond (Kuraray Medical) adhesive system followed by Clearfil AP-X hybrid composite: shade A3 (Kuraray Medical). The resins were light-cured with600mW/cm² for 40 s. After 24-h storage in water at 37°C, specimens were thermocycled for 5, 000 cycles between 5°C and 55°C. Dye penetration tests around the cavity margin and cavity wall on the cut surface were carried out for before and after thermocycling the specimens. Dye penetration length was calculated as a percentage of the total cavity wall length. Dye penetration scores (n=8) were analyzed using the Kruskal-Wallis test and the Mann-Whitney U test. Irradiation with 60 Gy γ-rays had no effect on resin composite adaptation to the cavity wall regardless of the bonding system used. However, the one-step bonding system showed significantly decreased cavity wall adaptation compared with the two-step bonding system Clearfil SE Bond for intact dentin.

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The purpose of this study was to determine the effects of resin hydrophilicity on dentin bonds. The study examined the microtensile bond strength of six experimental self-etching primers and two experimental bonds (50wt% ethanol/50wt% comonomers) of various degrees of hydrophilicity, that is various degrees of HEMA, to intact dentin. Following composite buildup, hourglass-shaped slabs were prepared from the bonded teeth for microtensile testing after24hours or6months. Higher bond strengths were achieved with increased resin hydrophilicity after 24hours, while the lowest bond strengths were achieved with increased resin hydrophilicity after6months. Measurements of water sorption/solubility of the polymers that were previously described showed high correlations between water sorption and the degree of HEMA, and between polymer solubility and the degree of HEMA.
These results indicated that higher resin hydrophilicity was effective for short-term microtensile strength, while increased resin hydrophilicity may cause lower bond strength due to the weakness of polymers that have absorbed water after 6 months.

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This study investigated the effect of the one-bottle bonding material “Absolute2” (Dentsply Sankin) on adhesion to contaminated dental hard tissues with artificial saliva and fetal bovine serum. Enamel and dentin discs were prepared from freshly extracted human premolars and the buccal surfaces were ground with #600 SiC paper under running water in this study. The contaminated dental hard tissues were made by dripping artificial saliva or fetal bovine serum of twenty milliliters for twenty seconds, and the control was dripped with distilled water of twenty milliliters for twenty seconds. The debonded specimens, resin-enamel and resin-dentin interfaces, and the enamel and dentin surfaces treated with Absolute2were observed by SEM.
The results showed no significant difference in bond strengths among all the groups. There were no morphological differences among all the groups by SEM observation. Cohesive failure in enamel as well as mixed failure were observed. Cohesive failure in dentin as well as mixed failure were observed in many cases in the debonded dentin group.
The results indicated that Absolute showed satisfactory adhesion to the contaminated hard tissues with artificial saliva and fetal bovine serum.

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The purpose of this study was to investigate the effect of mixing technique on the bond strengths of self-adhesive luting cements between ceramics and core resins.
Resin core blocks (Clearfil DC Core Automix) created in a mold and ceramic blocks (Vitablocs Mark II) were ground with #600 SiC paper to standardize the surface roughness. These blocks were bonded with one of the three self-adhesive luting cements (Smartcem, Maxcem and G-CEM), according to the manufacturers' instructions. Two techniques, auto-mixing with mixing tips or auto-mixing apparatus and hand-mixing with a spatula, were assigned for cement mixing. In order to standardize the cement thickness to 50 μm, masking tape was placed on the surfaces of the ceramics. After 24 hours' storage in water at 37°C, the specimens were trimmed to a beam shape (1.0×1.0mm²) and subjected to micro-tensile bond strength measurements. For each group, 10specimens were measured. The data were statistically analyzed with Tukey's HSD test.
The results showed no difference in mixing technique of self-adhesive luting cements on the bond strength between resin core blocks and ceramics blocks (p>0.05).

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The shear bond strengths between four indirect composite materials and a monomer-preimpregnated glass fiber material were determined in order to evaluate the compatibility of indirect composites with glass fiber material. Four indirect composites (Ceramage, Estenia C&B, New Meta Color Infis, and Pearleste) and a unidirectional long glass fiber material (Estenia C&B EG Fiber) were selected. A250-μm glass fiber plate was light-polymerized and air-abraded. After treatment with a silane primer and a bonding agent, the indirect composite materials were placed on the glass fiber plate and polymerized in accordance with the respective manufacturer's specifications. Shear bond strengths were determined both before and after thermocycling (4 and 60°C, 1min each, 10, 000 cycles) in accordance with ISO 11405. The results were compared using Tukey HSD tests and Mann-Whitney U-tests. The Estenia C&B and Pearleste materials showed significantly greater bond strengths than the other two composites before thermocycling (p<0.05). After thermocycling, there were no significant differences among the Ceramage, Estenia C&B, and Pearleste materials (p>0.05). The New Meta Color Infis material indicated the lowest bond strength among the four composites assessed, both before and after thermocycling (p<0.05). The type of composite material should be considered when selecting the optimal fiber-composite combination.

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The bonding effectiveness of three generations of resin bonding systems from the same manufacturer wasinvestigated in terms of nanoleakage. Cervical cavities of human extracted single root teeth were restored withMacbond II (MB), One-up Bond F Plus (OB) or Bond Force (BF), commercialized by Tokuyama Dental. Afterthermocycling5, 000times (TC, 5-55°C), the teeth were immersed into AgNO₃ solution and then developing solution.After the teeth were sectioned and embedded, the nanoleakage along the bonding interface was observed under SEM. In MB, nanoleakage at the gingival margin and along the cavity walls was found regardless of TC, whilethe gingival margin was slightly stained with silver in OB. No nanoleakage was found in BF regardless of TC andadhesion to the wall seemed to be tight. Furthermore, the so-called hybrid layer was not found at the bondinginterface.
BF, the latest system among the three generations, contains SR monomer that has been designed to havephosphate groups and polymerizable groups in a monomer molecule, resulting in higher bonding effectiveness. Acomparison of the multiple bonding systems produced by the same manufacturer may lead to revolutionarydevelopments in adhesive technology.

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The objective of this study was to evaluate bonding effectiveness in terms of the micro-tensile bond strength (MTBS) of adhesive resin cements to CAD/CAM hybrid resin blocks. Hybrid resin specimens fabricated from anexperimental hybrid resin block (experimental code: AGB-01, GC) were bonded with one of the following threeresin cements and ceramic primer: Linkmax (LM), Clearfil Esthetic Cement (EC), and ResiCem (RC). Specimenswere sectioned for the MTBS test, and were stored in37°C water for 24 h and thermocycled 0 or 5, 000 times beforethe test (n=12). The MTBS value of LM and RC were significantly higher than that of EC before the thermocycletest.
There was no significant difference in MTBS before and after the thermocycle test using the three resin cements.The hybrid resin block had a higher concentration of silica filler. Each primer including silane coupling agents waseffective for bonding the silica fillers to the base resin.

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The purpose of this study was to evaluate the effect of one-day storage on the bonding ability of self-adhesiveresin cement (SARC, RelyX Unicem Aplicap: 3M ESPE, G-Cem Capsule: GC, Clearfil SA Luting: KurarayMedical) and adhesive resin cements (ARC, ResiCem: Shofu, Clearfil Esthetic Cement: Kuraray Medical) tozirconia (Lava: 3M ESPE) and alumina (Vita In-Ceram Alumina, GC) with a composite inlay system (Z250, 3MESPE), and on the flexural strength and flexural modulus of these cements.
The shear bond strength of SARCs and ARCs to zirconia (Lava) after one-day storage was improved comparedwith the immediate condition. The shear bond strength to alumina (Vita In-Ceram Alumina) of SARCs after one-day storage was improved compared with the immediate condition, however, the case of ARCs did not show thispattern. This was caused by the development of the resin cement/zirconia (or alumina) interaction and the resincement itself, because of the increasing flexural strength and flexural modulus.

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A one-bottle/one-step resin bond “Bond Force^TR” was newly designed by Tokuyama Dental. This study examined the clinical performance of EsteliteΣ(Tokuyama Dental) composite restorations in combination with Bond Force^TR up to 18 months after placement according to the ADA Guideline. Minimally-invasive V-shape cavities were prepared in non-carious cervical lesions. The prepared cavities were treated with Bond Force^TR and filled with EsteliteΣ according to the manufacturer's instructions. A total of 39r estorations were placed in 39 patients (average age: 54.6, SD: 15.0). The evaluation items were retention, marginal discoloration, marginal adaptation, surface texture, abrasion, marginal fracture, body fracture, secondary caries, spontaneous pain, cold water pain, hot water pain, occlusal pain, gingival irritation, and soft tissue irritation. All the restorations were examined immediately after placement, at6, 12 and 18 month recalls. All the teeth restored were reported to be dentin cavities and vital at the time of placement of the restorations. Cold water pain in 3 cases, hot water pain in 2 cases, and occlusal pain in1case were observed before operation. All the restorations seemed to be clinically satisfactory in all aspects examined up to 18 months after placement. This clinical study has demonstrated that Bond Force^TR and EsteliteΣ are a satisfactory restorative system for minimally-invasive V-shape cervical cavities over a period of 18 months, and the Kaplan-Meier statistic was 1.0.

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This study was a clinical trial to determine the short-term efficacy of the one-bottle one-step bonding system “Clearfil Tri-S Bond^®” and restorative material “Clearfil Majesty”. A total of 30 restorations were placed in 30 human subjects in minimally invasive Class V and V-shape cervical cavities in permanent teeth by three operators. The baseline records were made immediately after placement according to the American Dental Association for assessment. Patients were followed up routinely at recall intervals up to 18 months and the restorations were evaluated for clinical acceptability. At eighteen months, all restorations were classified as clinically satisfactory and assigned an Alpha rating. No restorations recorded Bravo or Charlie. The Kaplan-Meier probability of survival rate for these restorations at eighteen months is 1.00. As a result, the short-term clinical performance with the Clearfil Tri-S Bond^® was very safe at 18 months after placement. It might be difficult to differentiate between the clinical performances of recently marketed bonding systems with high bonding efficacy, but performance is most affected by technical errors by operators.

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The aim of this study was to evaluate the bond strength of a newly-developed adhesive with different resin composites using a micro-tensile bond test. One experimental single-step adhesive, IMB-3 (IM), one commercially available adhesive, G-Bond (GB), and two composites, AP-X (AP) and Estelite Σ(ES), were used in this study. Flat dentin surfaces were prepared perpendicular to the long axis of the tooth. The surfaces were then ground with a regular-grit diamond point. Each adhesive was applied on the dentin surfaces according to the manufacturer's instructions using each resin composite. Four groups of bonded specimens were immersed in37°C water overnight. These specimens were sectioned in an approximately 1-mm² interface area, and then, subjected to the microtensile bond test at a crosshead speed of 1.0 mm/min. The data were analyzed by ANOVA and Games/Howell test (p<0.05). IMB-3 showed significantly higher bond strength with Estelite Σ than with AP-X. There was no significant difference in bond strength of the G-Bond group between the two resin composites. Within the limitations of this study, the results implied that the mechanical properties of resin composite affect the bond strength of adhesive resin to dentin.

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