• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.319-326
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• 2005

This study compared the microtensile bond strength $({\mu}TBS)$ of single step adhesives to different dentin depths. Superficial or deep dentin was exposed in 30 molar teeth by sectioning immediately under the DEJ or 1.5mm area from central pit, respectively. After polishing with 600-grit SiC paper, the dentin surfaces were assigned to three groups: AQ group-AQ Bond, L-Pop group-Adper Prompt L-Pop, Xeno group-Xeno III. The bonded specimens were sectioned into sticks and subjected to ${\mu}TBS$ testing with a crosshead speed of 1mm/minute. The results of this study were as follows; The ${\mu}TBS$ to superficial dentin was higher than that to deep dentin in all group. The ${\mu}TBS$ of Xeno group was significantly higher than that of L-Pop group and AQ group in both superficial and deep dentin (p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.348-357
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• 2009

The purpose of this study was to evaluate the micro-tensile bond strength (${\mu}TBS$) of four luting resin to regional dentin of human primary teeth. Dentin from non-carious primary molars were prepared from different regions (s, superficial dentin; d, deep dentin; c, cervical dentin), and divided into groups based on anatomical locations and types of luting resins (Scotchbond Multi-purpose : SB ; One-Step : OS ; AdheSE Bond : ASE ; G-Bond : GB) : SB-s, SB-d, SB-c; OS-s, OS-d, OS-c; ASE-s, ASE-d, ASE-c ; GB-s, GB-d, GB-c. Luting resins were used according to the manufacturers' instructions, to bond $Light-Core^{TM}$ Core Build-Up Composite) to the exposed dentin specimens in the light-curing mode. After storage for 1 day, ${\mu}TBS$ was tested at a cross-head speed of 1 mm/min. Data were analyzed with T-test and two-way ANOVA. The bonding interface and fractography analyses were performed with SEM. The results were as follows : 1. ${\mu}TBS$ to superficial dentin was significantly higher than to deep dentin for SB(p<0.05). But there were no significant differences in regional ${\mu}TBS$ among OS, ASE, GB(p>0.05). 2. There were no significant differences in ${\mu}TBS$ to superficial dentin among each groups. But, in deep dentin, ${\mu}TBS$ of SB-d was significantly lower than those of OS-d, ASE-d, and GB-d(p<0.05). ${\mu}TBS$ of OS-d was significantly higher than those of GB-d(p<0.05), but there were no significant differences in ${\mu}TBS$ of ASEd. There were no significant differences among ${\mu}TBS$ of ASE-d, OS-d, and GB-d.

• Restorative Dentistry and Endodontics
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• v.39 no.3
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• pp.195-200
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• 2014

Objectives: To comparatively evaluate the efficacy of photo-activated disinfection (PAD), calcium hydroxide (CH) and their combination on the treatment outcome of indirect pulp treatment (IPT). Materials and Methods: Institutional ethical clearance and informed consent of the patients were taken. The study was also registered with clinical registry of India. Sixty permanent molars exhibiting deep occlusal carious lesion in patients with the age range of 18 - 22 yr were included. Clinical and radiographic evaluation and set inclusion and exclusion criteria's were followed. Gross caries excavation was accomplished. In group I (n = 20) PAD was applied for sixty seconds. In group II (n = 20), CH was applied to the remaining carious dentin, while in group III (n = 20), PAD application was followed by CH placement. The teeth were permanently restored. They were clinically and radiographically followed-up at 45 day, 6 mon and 12 mon. Relative density of the remaining affected dentin was measured by 'Radiovisiography (RVG) densitometric' analysis. Results: Successful outcome with an increase in radiographic grey values were observed in all three groups. However, on inter-group comparison, this change was not significant (p > 0.05). Conclusions: PAD and CH both have equal disinfection efficacy in the treatment of deep carious dentin. PAD alone is as effective for treatment of deep carious lesion as calcium hydroxide and hence can be used as an alternative to CH. They can be used independently in IPT, since combining both does not offer any additional therapeutic benefits.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.65-76
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• 1986

Carious dentin can be classified, on the basis of their clinical characteristics, into three groups; sound, sclerotic and active carious dentin. Active carious dentin differs from sclerotic dentin by its abscence of variable bacteria within tubles and amount of chemical content. But the apatite molecules of active carious dentin are not fully studied. The purpose of this study was to observed the physico-chemical characteristics of deep carious dentin. The samples of sound, sclerotic and active carious dentin were obtained respectively from 300 freshly extracted carious teeth. Bacterial-rich zone of superficial soft dentin layer was removed with hand instruments from all samples in advance. The samples were powdered and sieved (200 mesh) before analyses. Identification and estimation of the crystallinity of the samples were carried with X-ray diffraction and infrared absorption analyses. Measurements were made on a Rigaku Denki (Rigaku, geiger flex III, Japan) X-ray diffractometer with Cu-target at 30 Kv, 30 mA and are traced on a monochromatic tracer. Infrared absorption analysis was made on FT-IR spectrophometer (Nicolet Instrument Co.) using KBr pellets containing the samples and was recorded on data process (Model IR-80. Nicolet Instrument, Co). The following conclusions were as follows; 1. The nature of the main inorganic structure of sound, sclerotic and active carious dentin proved to be hydroxyapatite. 2. It was difficult to determine the identification due to their crystallinity of sound, sclerotic and active carious dentin. But sound dentin was the highest in crystallinity among them. 3. The magnesium whitlockite was to be found in active carious dentin, but not in sound and sclerotic dentin. 4. The carbonate content was highest in sound dentin, but the lowest was in active carious dentin.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.227-241
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• 1996

The effect of collagen dissolution in acid conditioned dentin was morphologically examined by both scanning and transmission electron microscopy. 18 freshly extracted human molars and dentin bonding systems of All Bond 2, Scotchbond Multipurpose, Superbond D-Liner were used in this study. For SEM preparation, each 3 of ~ exposed dentin surfaces were acid conditioned by using various acids within the above three bonding systems respectively. After acid conditioning of the other 3 exposed dentin surfaces as above, they were treated with 1.7% NaOCl for 2 minutes. The remaining 3 dentin surfaces were acid conditioned and treated with 3.3 % NaOCl for 2 minutes. All of the specimens were then fixed in 4 % glutaraldehyde for 12 h at $4^{\circ}C$ and dehydrated in ethanols grades from 50 % to 100 %, then surface changes of the specimens were observed by using SEM. For TEM preparation, exposed dentin surfaces were acid conditioned with the same acid as SEM specimens and treated with 1.7%, 3.3 % NaOCl respectively, then applied with corresponding bonding agents. After the procedures were finished, composite resin were applied on the dentin surfaces and light cured. Small, rectangular sticks with end dimensions of approximately 1 by 1 mm were sectioned and further sample preparative techniques for transmission electron microscopy were performed in accordance with the procedures used for ultrastructural TEM observations of calcified tissues. The results were as follows : 1. In the 1.7 % NaOCl retreated specimens after acid conditioning, the porous dentin surface of intertubular dentin and wide opening of dentinal tubules were appeared. And there were fine irregularities on the intertubular dentin, indicating a clear difference as compared with the acid conditioned specimens. 2. In the 3.3% NaOCl retreated specimens after acid conditioning, the intertubular dentin was further eroded causing a more porous and wider opening of dentinal tubules. Moreover, sharp irregularities on the intertubular dentin were more evident than those of acid conditioned and 1.7% NaOCl retreated specimens. 3. In all of the acid conditioned specimens, the resin-dentin hybrid layer of approximately 3.5mm thickness was formed and the collapsed collagen layer was observed on the uppermost part of hybrid layer in the specimens applied with All Bond 2. The collgen fibrils of intertubular dentin in specimens applied with Scotchbond Multipurpose were running perpendicular to the interface, and electron dense black layer demarcated from the deep unaltered dentin was more evident in the specimen applied with Superbond D-Liner than any other specimens. 4. In the 1.7 % NaOCl retreated specimens after acid conditioning, the resin-dentin hybrid layer of approximately 2.5-3.0mm thickness was formed and the collapsed collagen layer and longitudinally running collagen fibrils as shown in the acid conditioned specimens were observed in the specimens applied with All Bond 2 and Superbond D-Liner. 5. In all of the 3.3% NaOCl retreated specimens after acid conditioning, the evidence of resin-dentin hybrid layer was not identified ; nevertheless, the longitudinally running collagen fibrils remained slightly in the specimens applied with All Bond 2.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.101-108
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• 1987

The purpose of this study was to investigate the pulpal responses of dental adhesive resins. A total of 40 cavities of the permanent healthy teeth from 4 dogs were prepared. In the experimental group, the cavities were etched for 1 minute with citric acid and filled with experimental resins (ie. Super-Bond C & B$^{(R)}$). In the control group, the cavities were filled with calcium hydroxide base materials (ie. Dycal$^{(R)}$) without etching. The dogs were sacrificed at one, two, three and four weeks after the time of filling and the specimens were routinely prepared and stained with Hematoxylin-Eosin. The microscopic findings were as follows: Infiltration of inflammatory cells was not observed in both experimental and control groups. Change in the odontoblastic layer was not observed in all control groups but severe swelling was observed in deep dental pulp tissue of the control two and three week cases. Pulp tissue was recovered with plenty of fibrous component in the control four week case and reparative dentin formation was not occurred in all cases. Slight changes of the odontoblastic layer beneath the cavity were observed in the experimental one week case. In experimental two and three week cases, swelling of deep pulp tissue was increased and localized reparative dentin formation was observed. In the experimental four week case, odontoblastic layer was recovered with regular appearance and fibrous component of the pulp was increased, but reparative dentin formation was not evident.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.214-234
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• 1995

The purpose of this work was to study the compatibility of several commercially available dentin adhesives with composite resins. In this study, V-shaped cavity preparations were created on both buccal and lingual surfaces of 60 extracted human premolars($3mm{\times}3mm{\times}2mm$ deep). Preparations were located such that the occlusal margins were on the enamel and the gingival margins were on the cementum(1mm below the CEJ). These specimens were randomly divided into three equal groups. Three dentin adhesives(Scotchbond Multi-Purpose, All Bond 2, Prisma Universal Bond 3)were applied to the cavity in accordance with each manufacturer's instructions. The teeth in each group were restored with four composite resins(Silux plus, Z100, Bisfil, Prisma TPH) in three increments, with each increment light-cured for 40 seconds. All specimens were exposed to 500 cycles of thermal stress. Specimens then placed in a silver nitrate solution(50% by weight) and stored in darkness for 24 hours. They were then immersed for 6 hours in photographic developing solution under flourescent light. Specimens were sectioned buccolingually through the center of the restoration and observed under a binocular stereoscope. To compare the marginal leakage, ANOVA and Dunkan's multiple range tests were used in analysis. Selected samples were further studied using scanning electron microscopy(XL20, Philips, The Netherlands). The results were as follows. 1. In all groups, the enamel margin showed significantly less leakage than the cementum margin. 2. No statistically significant differences were found in microleakage when composite resins were used with their proprietary dentin adhesives. 3. In comparison between dentin adhesives, Prisma Universal Bond 3 showed significantly less leakage at the enamel margin and Scotch bond multi-purpose showed significantly less leakage at the cementum margin than the other groups. 4. In comparison between composite resins, Silux Plus showed significantly more leakage than other groups at the enamel margin and no statistically significant differences were found in microleakage at the cementum margin. 5. According to the backscattered scanning electron microscope, microleakage occurred via gaps at the dentin adhesives/dentin interface.

• Restorative Dentistry and Endodontics
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• v.13 no.2
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• pp.323-334
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• 1988

The purpose of this study was to observe the effect of dentin surface conditioners on the dentin surfaces. Freshly extracted human molars were used in this study. They were stored at $4^{\circ}C$ saline solution before experiment. The crown portions of the teeth were cut in various directions by means of wet diamond point to expose dentin which include transverse, vertical oblique, horizontal and oblique cut to the long axis (Fig. 1). Each tooth was then mounted with self curing acrylic resin in brass ring to expose the flattened dentin surfaces. Final finish was accomplished by grinding the dentin specimens with wet No. 180 and No. 600 grit silicon carbide abrasive paper until a 6.0mm in diameter on a dentin surface was exposed without pulp exposure. The specimens were divided into 9 groups according to the modes of dentin treatment procedure. The following surface treatments were applied on these preparation surfaces; Group 1: unetched (control group) after finish with No. 600 silicon carbide abrasive paper. Group 2: etched with 30% phosphoric acid for 60s Group 3: etched with 10-3 solution for 60s Group 4: Cleaned with 5% NaOCl for 30s Group 5: applied Dentin Adhesit Group 6: cleaned with 5% NaOCl followed by applying the Dentin Adhesit$^{(R)}$ Group 7: applied Photo Bond on the unetched dentin followed by applying the Photo Clearfil Bright Group 8: Etched with 30% phosphoric acid followed by applying Photo Bond and Photo Clearfil Bright Group 9: etched with 10-3 solution followed by applying Photo Bond and Photo Clearfil Bright All the specimens were stored in $37^{\circ}C$ under 50% relative humidity for 24 hours before observations. The specimens in 7, 8, and 9 group, omitting the group 1 to 6, were demineralized in 10% HCl for 10s in order to observe the resin tags. All the specimens in each group were then dried at room temperature. The dried specimens were ion coated with Eiko ion coater (Eiko-engineering Co.), and observed in Hitachi S-430 Scanning electron microscope (Hitachi, Co. Tokyo) at 15KV. The following results were obtained as follows; 1. The smear layers were still remained in group 1,2,4,5, and 6. 2. There is no effect of 5% NaOCl and 30% phosphoric acid on the changes of dentin morphology 3. The dentin treated with 10-3 solution, indicating the tubules opened when the smear layer and the dental plug dissolved. 4. In case of applying the bonding agents the resin tag was not formed at the deep area of dentinal tubules, but in case of applying the Dentin Adhesit$^{(R)}$ that was not.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.406-414
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• 2009

The purpose of this study was to examine the effect of hydrogen peroxide at different application time and concentrations on the microtensile bond strength of resin restorations to the deep and the pulp chamber dentin. A conventional endodontic access cavity was prepared in each tooth, and then the teeth were randomly divided into 1 control group and 4 experimental groups as follows: Group 1, non treated; Group 2, with 20% Hydrogen peroxide ($H_2O_2$); Group 3, with 10% $H_2O_2$; Group 4, with 5% $H_2O_2$; Group 5, with 2.5% $H_2O_2$; the teeth of all groups except group 1 were treated for 20, 10, and 5min. The treated teeth were filled using a Superbond C&B (Sun medical Co., Shiga, Japan). Thereafter, the specimens were stored in distilled water at $37^{\circ}C$ for 24-hours and then sectioned into the deep and the chamber dentin. The microtensile bond strength values of each group were analyzed by 3-way ANOVA and Tukey post hoc test(p < 0.05). In this study, the microtensile bond strength of the deep dentin (D1) was significantly greater than that of the pulp chamber dentin (D2) in the all groups tested. The average of microtensile bond strength was decreased as the concentration and the application time of $H_2O_2$ were increased. Analysis showed significant correlation effect not only between the depth of the dentin and the concentration of $H_2O_2$ but also between the concentration of H202 and the application time(p < 0.05), while no significant difference existed among these three variables(p > 0.05). The higher $H_2O_2$ concentration, the more opened dentinal tubules under a scanning electron microscope(SEM) examination.

• Restorative Dentistry and Endodontics
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• v.47 no.4
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• pp.36.1-36.17
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• 2022

Objectives: This study aimed to evaluate the effect of aging on the marginal quality of glass hybrid (GH) material used to elevate dentin gingival margins, and to analyze the consistency of the results obtained by 3 in vitro methods. Materials and Methods: Ten teeth received compound class II cavities with subgingival margins. The dentin gingival margins were elevated with GH, followed by resin composite. The GH/gingival dentin interfaces were examined through digital microscopy, scanning electron microscopy (SEM) using resin replicas, and according to the World Dental Federation (FDI) criteria. After initial evaluations, all teeth were subjected to 10,000 thermal cycles, followed by repeating the same marginal evaluations and energy dispersive spectroscopy (EDS) analysis for the interfacial zone of 2 specimens. Marginal quality was expressed as the percentage of continuous margin at ×200 for microscopic techniques and as the frequency of each score for FDI ranking. Data were analyzed using the paired sample t-test, Wilcoxon signed-rank test, and Pearson and Spearmen correlation coefficients. Results: None of the testing techniques proved the significance of the aging factor. Moderate and strong significant correlations were found between the testing techniques. The EDS results suggested the presence of an ion-exchange layer along the GH/gingival dentin interface of aged specimens. Conclusions: The marginal quality of the GH/dentin gingival interface defied aging by thermocycling. The replica SEM and FDI ranking results had stronger correlations with each other than either showed with the digital microscopy results.