• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.389-396
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• 2002

The purpose of this study was to compare the microtensile bonding strength of chemomechanically excavated dentin($Carisolv^{TM}$) to conventional caries removal(bur). The following adhesive systems were used; AB: All-Bond 2(3M, USA), PB: Prime & Bond 2.1(Dentsply, DE), AQ: AQ Bond(sun medical, Japan). 42 human molars with occlusal caries were assigned to 6 groups. Sequential caries removal was controlled with laser fluorescence. Each group was devided as follows; group A, B, C were $Carisolv^{TM}$ applied, group D,E,F were bur used. In group A and D, AB was used as a dentin adhesive. group B,E and group C,F was AQ and AQ was used each. The cavity was filled with composite resin(Z-100). The specimens were sectioned vertically into multiple serial 0.7 mm thick slabs. And then those slabs were sectioned into rectangular parts under 0.7 mm width. Finally 0.7-1.0 mm a right hexahedron shape stick become. Microtensile bonding test was carried out with testing apparatus at cross-head speed of $0.5\;mm/min^{-1}$ and fractured surfaces were observed with scanning electron microscope(JSM-6400, Jeol, Japan). The obtained results were summarized as follows ; 1. In the group of caries removal with $Carisolv^{TM}$, micro-tensile bonding strength decreased to $75.8{\sim}80$ percent of bur used group. 2. In the group of caries removal with $Carisolv^{TM}$, decreased degree of micro-tensile bonding strength is not so different in 3 kinds of dentin adhesives(p<0.05). 3. In the group of caries removal with $Carisolv^{TM}$, microtensile bonding strength of AB, PB, AQ was 32.6MPa(2.4), 30.1Mpa (1.8), 21.2Mpa(1.9). 4. In the group of caries removal with Bur and $Carisolv^{TM}$, microtensile bonding strength of AQ was significantly lower than that of AB and PB(p<0.01).

• Restorative Dentistry and Endodontics
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• v.29 no.1
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• pp.51-57
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• 2004

본 연구는 에폭시레진계 봉함제 (AH26)과 두 가지의 상아질 접착제와 함께 근관충전을 시 행하였을 때와 에폭시레진계 봉함제 단독으로 사용하였을 때의 미세누출을 혐기성 세균모델을 이용하여 평가하였다. 52개의 단근치를 이용하여 .04, .06 taper Profile (Dentsply-Maillefer, Ballaigues, Swiss)을 사용하여 변형된 crown-down pressureless법으로 근관형성 하였다. 형성된 치근을 12개씩 무작위로 나누어 4개의 실험군으로 하였으며, 나머지 치아 중 2개를 양성대조군에, 2개는 음성대조군으로 사용하였다. 제1군은 All Bond 2(Bisco, Itasca, IL, USA)를 적용하고 거타퍼쳐와 AH26 (Dentsply, Konstanz, Germany)을 이용하여 continuous wave of condensation technique으로 근관충전 하였으며, 제 2군은Prime ＆ Bond NT (Dentsply, Konstanz, Germany)를 적용 후 거타퍼쳐와 AH26을 이용하여 충전하였으며, 제3군은 17％ EDTA를 적용하여 도말층을 제거한 후 거터퍼쳐 와 AH26을 사용하여 충전하였다. 제4군은 17％ EDTA를 적용하지 않고 거터퍼쳐와 AH26을 사용하여 충전하였다. Fusobacterium nucleatum (VPI 10197)을 추적자로 이용한 혐기성세균모델을 사용하여 혐기성배양기에서 배양시키면서 60일 동안 각군에 대한 미세누출 여부를 관찰하였다. 매일 배양액의 혼탁도와 색상변화를 관찰하여 기록하였다. 제4군에서 통계학적으로 유의할만한 미세누출을 가장 많이 보였으며(p<0.0005) 나머지 3개의 실험군에서는 서로간의 통계학적으로 유의할 만한 차이를 보이지 않았다. 주사전자현미경 관찰 시 제 1군과 제2군의 상아질 접착제가 상아세관으로 침투한 소견을 관찰 할 수 있었다.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.264-270
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• 2023

Background: Resin-based dental materials release residual monomers or other substances from incomplete polymerization into the oral cavity, thereby causing adverse biological effects on oral tissue. 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP), an acidic monomer containing dihydrogen phosphate and methacrylate groups, is the most commonly used component of resin-based dental materials, such as restorative composite resins, dentin adhesives, and resin cements. Although previous studies have reported the cytotoxicity and biocompatibility in various cultured cells, the effects of resin monomers on cellular aging have not been reported to date. Therefore, this study aimed to investigate the effects of the resin monomer 10-MDP on cellular senescence and inflamm-aging in vitro. Methods: After stimulation with 10-MDP, MC3T3-E1 osteoblast-like cells were examined for cell viability by WST-8 assay and reactive oxygen species (ROS) production by flow cytometry. The protein and mRNA levels of molecular markers of aging were determined by western blotting and RT-PCR analysis, respectively. Results: Treatment with 0.05 to 1 mM 10-MDP for 24 hours reduced the survival of MC3T3-E1 cells in a concentration-dependent manner. The intracellular ROS levels in the 10-MDP-treated experimental group were significantly higher than those in the control group. 10-MDP at a concentration of 0.1 mM increased p53, p16, and p21 protein levels. Additionally, an aging pattern was observed with blue staining due to intracellular senescence-associated beta-galactosidase activity. Treatment with 10-MDP increased the levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-8, however their expression was decreased by mitogen-activated-protein-kinase (MAPK) inhibitors. Conclusion: Taken together, these results suggest that the exposure of osteoblast-like cells to the dental resin monomer 10-MDP, increases the level of cellular senescence and the inflammatory response is mediated by the MAPK pathway.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.9-19
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• 2008

The purpose of this study was: (1) to compare nanoleakage patterns of a conventional 3-step etch and rinse adhesive system and two experimental hydrophobic adhesive systems and (2) to investigate the change of the nanoleakage patterns after load cycling. Two kinds of hydrophobic experimental adhesives, ethanol containing adhesive (EA) and methanol containing adhesive (MA), were prepared. Thirty extracted human molars were embedded in resin blocks and occlusal thirds of the crowns were removed. The polished dentin surfaces were etched with a 35 % phosphoric acid etching gel and rinsed with water. Scotchbond Multi-Purpose (MP), EA and MA were used for bonding procedure. Z-250 composite resin was built-up on the adhesive-treated surfaces. Five teeth of each dentin adhesive group were subjected to mechanical load cycling. The teeth were sectioned into 2 mm thick slabs and then stained with 50 % ammoniacal silver nitrate. Ten specimens for each group were examined under scanning electron microscope in backscattering electron mode. All photographs were analyzed using image analysis software. Three regions of each specimen were used for evaluation of the silver uptake within the hybrid layer. The area of silver deposition was calculated and expressed in gray value. Data were statistically analyzed by two-way ANOVA and post-hoc testing of multiple comparisons was done with the Scheffe's test. Silver particles were observed in all the groups. However, silver particles were more sparsely distributed in the EA group and the MA group than in the MP group (p < .0001). There were no changes in nanoleakage patterns after load cycling.

• Restorative Dentistry and Endodontics
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• v.34 no.1
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• pp.51-60
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• 2009

The purpose of this study was to perform quantitative comparisons of water permeable zones in both the adhesive and the hybrid layer before and after thermo cycling in order to assess the integrity of the bonding interface. Twenty eight flat dentin surfaces were bonded with a light-cured composite resin using one of four commercial adhesives [OptiBond FL (OP), AdheSE (AD), Clearfil SE Bond (CL). and Xeno III (XE)]. These were sectioned into halves and subsequently cut to yield 2-mm thick specimens; one specimen for control and the other subjected to thermocycling for 10,000 cycles. After specimens were immersed in ammoniacal silver nitrate for 24 h and exposed to a photo developing solution for 8 h, the bonded interface was analyzed by scanning electron microscopy (SEM) and wavelength dispersive spectrometry (WDS) at five locations per specimen. Immediately after bonding. the adhesive layer of OP showed the lowest silver uptake, followed by CL, AD. and XE in ascending order (p < 0.0001); the hybrid layer of CL had the lowest silver content among the groups (p = 0.0039). After thermocycling, none of the adhesives manifested a significant increase of silver in either the adhesive or the hybrid layer. SEM demonstrated the characteristic silver penetrated patterns within the interface. It was observed that integrity of bonding was well maintained in OP and CL throughout the thermocycling process. Adhesive-tooth interfaces are vulnerable to hydrolytic degradation and its permeability varies in different adhesive systems, which may be clinically related to the restoration longevity.

• Restorative Dentistry and Endodontics
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• v.31 no.2
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• pp.103-112
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• 2006

This study investigated the hypothesis that the dentin bond strength of self-etching adhesive (SEA) might be improved by applying additional layer of bonding resin that might alleviate the pH difference between the SEA and the restorative composite resin. Two SEAs were used in this study; Experimental SEA (Exp, pH: 1.96) and Adper Prompt (AP, 3M ESPE, USA, pH: 1.0) In the control groups they were applied with two sequential coats In the experimental groups, after applying the forst coat of assigned SEAs, the D/E bonding resin of All-Bond 2 (Bisco Inc., USA, pH: 6.9) was applied as the intermediate adhesive. Z-250 (3M ESPE, USA) composite resin was built-up in order to prepare hourglass-shaped specimens . The microtensile bond strength (MTBS) was measured and the effect of the Intermediate layer on the bond strength was analyzed for each SEA using t-test. The fracture mode of each specimen was inspected using stereomicroscope and Field Emission Scanning Electron Microscope (FE-SEM). When D/E bonding resin was applied as the second coat, MTBS was significantly higher than that of the control groups . The incidence of the failure between the adhesive and the composite or between the adhesive and dentin decreased and that of the failure within the adhesive layer increased. According to the results , applying the bonding resin of neutral pH can increase the bond strength of SEAs by alleviating the difference in acidity between the SEA and restorative composite resin.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.148-156
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• 2008

Statement of problems: Self-etch adhesives exhibit some clinical benefits such as ease of manipulation and reduced technique-sensitivity. Nevertheless, some concern remains regarding the bonding effectiveness of self-etch adhesives to enamel, in particular when so-called 'mild' self-etch adhesives are employed. This study compared the microtensile bond strengths to ground enamel of the two-step self-etch adhesive Clearfil SE Bond (Kuraray) to the three-step etch-and- rinse adhesive Scotchbond Multi-Purpose (3M ESPE) and the one-step self-etch adhesive iBond (Heraeus Kulzer). Purpose: The purpose of this study was to determine the effect of a preceding phosphoric acid conditioning step on the bonding effectiveness of a two-step self-etch adhesive to ground enamel. Material and methods: The two-step self-etch adhesive Clearfil SE Bond non-etch group, Clearfil SE Bond etch group with prior 35% phosphoric acid etching, and the one-step self-etch adhesive iBond group were used as experimental groups. The three-step etch-and-rinse adhesive Scotchbond Multi-Purpose was used as a control group. The facial surfaces of bovine incisors were divided in four equal parts cruciformly, and randomly distributed into each group. The facial surface of each incisor was ground with 800-grit silicon carbide paper. Each adhesive group was applied according to the manufacturer's instructions to ground enamel, after which the surface was built up using Light-Core (Bisco). After storage in distilled water at $37^{\circ}C$ for 1 week, the restored teeth were sectioned into enamel beams approximately 0.8*0.8mm in cross section using a low speed precision diamond saw (TOPMET Metsaw-LS). After storage in distilled water at $37^{\circ}C$ for 1 month, 3 months, microtensile bond strength evaluations were performed using microspecimens. The microtensile bond strength (MPa) was derived by dividing the imposed force (N) at time of fracture by the bond area ($mm^2$). The mode of failure at the interface was determined with a microscope (Microscope-B nocular, Nikon). The data of microtensile bond strength were statistically analyzed using a one-way ANOVA, followed by Least Significant Difference Post Hoc Test at a significance level of 5%. Results: The mean microtensile bond strength after 1 month of storage showed no statistically significant difference between all adhesive groups (P>0.05). After 3 months of storage, adhesion to ground enamel of iBond was not significantly different from Clearfil SE Bond etch (P>>0.05), while Clearfil SE Bond non-etch and Scotchbond Multi-Purpose demonstrated significantly lower bond strengths (P<0.05), with no significant differences between the two adhesives. Conclusion: In this study the microtensile bond strength to ground enamel of two-step self-etch adhesive Clearfil SE Bond was not significantly different from three-step etch-and-rinse adhesive Scotchbond Multi-Purpose, and prior etching with 35% phosphoric acid significantly increased the bonding effectiveness of Clearfil SE Bond to enamel at 3 months.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.632-640
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• 2002

The objective of the study was to apply the vibration technique to reduce the viscosity of bonding adhesives and thereby compare the bond strength and resin penetration into dentinal tubules achieved with those gained using the conventional technique. Eighty-eight noncarious extracted human permanent molar teeth were sectioned to remove the coronal enamel and were embedded in 1-inch PVC pipe with acrylic resin. The occlusal surfaces were placed so that the tooth and the embedding medium were at the same level to form one flat surface, and the samples were subsequently polished with silicon carbide abrasive papers. The samples were randomly assigned to 4 groups(n=22). On Group 1 and 2, Single Bond(3M-ESPE, St. Paul, USA) was used, and on Group 3 and 4, One-Step(Bisco Inc., Schaumburg, USA) was used, and each was applied according to its manufacturer's instructions. For Group 2 and Group 4, vibration was applied with ultrasonic scaler for 10 seconds, and the adhesive was light-cured for 10 seconds. Resin composite was condensed on to the prepared surface in two increments using a mold kit(Ultradent Products Inc., USA) and each was light-cured for 40 seconds. After 24 hours in tap water at room temperature the specimens were thermocycled, and shear bond strengths were measured with a universal testing machine(Instron 4465, Canton, USA). To investigate infiltration patterns of the adhesive materials, the surface of specimen was examined with scanning electron microscope. The results were as follows. 1. The shear bond strengths of vibration groups(Group 2, Group 4) were significantly greater than those of the non-vibration groups(Group 1, Group 3)(p<0.05). 2. The shear bond strengths of Single Bond and One-Step were not significantly different (p>0.05). 3. The vibration groups showed greater number of resin tags in tubules and lateral branches under SEM.