• Journal of Periodontal and Implant Science
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• v.49 no.1
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• pp.25-38
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• 2019

Purpose: This study evaluated differences in bone healing and remodeling among 3 implants with different surfaces: sandblasting and large-grit acid etching (SLA; IS-III $Active^{(R)}$), SLA with hydroxyapatite nanocoating (IS-III $Bioactive^{(R)}$), and SLA stored in sodium chloride solution ($SLActive^{(R)}$). Methods: The mandibular second, third, and fourth premolars of 9 dogs were extracted. After 4 weeks, 9 dogs with edentulous alveolar ridges underwent surgical placement of 3 implants bilaterally and were allowed to heal for 2, 4, or 12 weeks. Histologic and histomorphometric analyses were performed on 54 stained slides based on the following parameters: vertical marginal bone loss at the buccal and lingual aspects of the implant (b-MBL and l-MBL, respectively), mineralized bone-to-implant contact (mBIC), osteoid-to-implant contact (OIC), total bone-to-implant contact (tBIC), mineralized bone area fraction occupied (mBAFO), osteoid area fraction occupied (OAFO), and total bone area fraction occupied (tBAFO) in the threads of the region of interest. Two-way analysis of variance (3 types of implant $surface{\times}3$ healing time periods) and additional analyses for simple effects were performed. Results: Statistically significant differences were observed across the implant surfaces for OIC, mBIC, tBIC, OAFO, and tBAFO. Statistically significant differences were observed over time for l-MBL, mBIC, tBIC, mBAFO, and tBAFO. In addition, an interaction effect between the implant surface and the healing time period was observed for mBIC, tBIC, and mBAFO. Conclusions: Our results suggest that implant surface wettability facilitates bone healing dynamics, which could be attributed to the improvement of early osseointegration. In addition, osteoblasts might become more activated with the use of HA-coated surface implants than with hydrophobic surface implants in the remodeling phase.

• Journal of dental hygiene science
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• v.22 no.3
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• pp.156-163
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• 2022

Background: This study attempted to apply resin infiltrant (RI) as a method to maintain the effect of tooth bleaching treatment and compared it with fluoride varnish (FV) or artificial saliva to evaluate the effect. Methods: Sixty healthy lozenge specimens were classified into five groups. Group 1 was the negative control group, and discoloration was induced after artificial saliva treatment of the tooth specimen (G1_S+C). Group 2 was a positive control group, in which pigmentation was induced after bleaching treatment and artificial saliva treatment (G2 _B+S+C). Coloration was induced in group 3 (experimental group 1) after bleaching treatment and artificial saliva treatment, followed by application of fluorine varnish (G3_B+FV+S+C). Coloration was induced in Group 4 (experimental group 2) after applying RI after bleaching treatment and artificial saliva treatment (G4_B+RI+S+C). Pigmentation was induced in group 5 (experimental group 3) after bleaching treatment and artificial saliva treatment, followed by acid treatment (etching) and treatment with RI (G5_B+E+RI+S+C). Coffee and wine were used to induce discoloration. The lightness value (L^*) of the CIE L^*a^*b^* color system was obtained by image analysis. Kruskal-Wallis H analysis was performed for the mean difference in L^* values by group. Results: When coloration was induced with coffee, there was no significant difference in L^* value between artificial saliva (G2 _B+S+C), FV (G3_B+FV+S+C), and RI (G4_B+RI+S+C, G5_B+E+RI+S+C) groups. There was no significant difference in L^* values between the artificial saliva (G2 _B+S+C), FV (G3_B+FV+S+C), and RI (G4_B+RI+S+C, G5_B+E+RI+S+C) groups, even in the case of wine induced coloration. Conclusion: It was confirmed that artificial saliva or RI treatment had similar effects to the FV previously used to maintain the effect of tooth bleaching treatment.

• Restorative Dentistry and Endodontics
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• v.48 no.2
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• pp.13.1-13.11
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• 2023

Objectives: Natural extracts have been investigated as a biomimetic strategy to mechanically strengthen the collagen network and control the biodegradation of extracellular matrix. This study evaluated the effect of epigallocatechin-3-gallate (EGCG) on abfraction lesions prior to the composite resin. Materials and Methods: The sample consisted of 30 patients (aged between 28 and 60 years) with abfraction lesions located in 2 homologous premolars. The teeth were randomly assigned according to dentin treatment: 0.02% EGCG solution or distilled water (control). After enamel acid etching, the solutions were applied immediately for 1 minute. The teeth were restored with Universal Adhesive (3M) and Filtek Z350 XT (3M). Analyzes were done by 2 independent examiners using modified USPHS (retention, secondary caries, marginal adaptation, and postoperative sensitivity) and photographic (color, marginal pigmentation, and anatomical form) criteria at baseline (7 days) and final (18 months). The data analysis used Friedman and Wilcoxon signed-rank tests (α = 0.05). Results: At baseline, all restorations were evaluated as alpha for all criteria. After 18 months, restorations were evaluated as alpha for secondary caries, color, and marginal pigmentation. There was significant difference between baseline and 18 months (p = 0.009) for marginal adaptation and postoperative sensitivity (p = 0.029), but no significant difference were verified between treatments (p = 0.433). The EGCG group had a restoration retention rate of 93.3%, while the control group had 96.7%. Conclusions: The application of EGCG solution on abfraction lesions did not significantly influence the survival of the restorations based on clinical and photographic criteria.

• Analytical Science and Technology
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• v.19 no.5
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• pp.394-399
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• 2006

The polishing performance and the relationships of electrochemistry depending upon oxidizers and additives in the tungsten CMP slurry used in semiconductor industry were investigated. Hydrogen peroxide, ferric nitrate and potassium iodate were used as oxidizers and they showed different oxidation reactions on tungsten film depending on the kind of oxidizers and pH of slurry. The differences influenced the polishing performance. Etching reaction was predominated in the hydrogen peroxide. However, passivation reaction was prevailed in ferric nitrate and potassium iodate. TMAH and KOH raised the potential energy and removal rate of tungsten, and improved a dispersion characteristic of slurry by increasing absolute value of zeta potential. Addition of 100 ppm of poly(acrylic acid) of M.W. 250,000 improved dispersion ability.

• Restorative Dentistry and Endodontics
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• v.36 no.4
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• pp.280-289
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• 2011

Objectives: The purpose of this study was to evaluate ${\mu}TBS$ (microtensile bond strength) of current dentin bonding adhesives which have different hydrophobicity with low-shrinkage silorane resin. Materials and Methods: Thirty-six human third molars were used. Middle dentin was exposed. The teeth were randomly assigned to nine experimental groups: Silorane self-etch adhesives (SS), SS + phosphoric acid etching (SS + pa), Adper easy bond (AE), AE + Silorane system bonding (AE + SSb), Clearfil SE bond (CSE), CSE + SSb, All-Bond 2 (AB2), AB2 + SSb, All-Bond 3 (AB3). After adhesive's were applied, the clinical crowns were restored with Filtek LS (3M ESPE). The 0.8 mm ${\times}$ 0.8 mm sticks were submitted to a tensile load using a Micro Tensile Tester (Bisco Inc.). Water sorption was measured to estimate hydrophobicity adhesives. Results: ${\mu}TBS$ of silorane resin to 5 adhesives: SS, 23.2 MPa; CSE, 19.4 MPa; AB3, 30.3 MPa; AB2 and AE, no bond. Additional layering of SSb: CSE + SSb, 26.2 MPa; AB2 + SSb, 33.9 MPa; AE + SSb, no bond. High value of ${\mu}TBS$ was related to cohesive failure. SS showed the lowest water sorption. AE showed the highest solubility. Conclusions: The hydrophobicity of adhesive increased, and silorane resin bond-strength was also increased. Additional hydrophobic adhesive layer did not increase the bond-strength to silorane resin except AB2 + SSb. All-Bond 3 showed similar ${\mu}TBS$ & water sorption with SS. By these facts, we could reach a conclusion that All-Bond 3 is a competitive adhesive which can replace the Silorane adhesive system.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.31-37
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• 2013

Lowering surface reflectance of Si wafers by texturization is one of the most important processes for improving the efficiency of Si solar cells. This paper presents the results on the effect of texturing using acidic solution mixtures containing the catalytic agents to moderate etching rates on the surface morphology of mc-Si wafer as well as on the performance parameters of solar cell. It was found that the treatment of contaminated crystalline silicon wafer with $HNO_3-H_2O_2-H_2O$ solution before the texturing helps the removal of organic contaminants due to its oxidizing properties and thereby allows the formation of nucleation centers for texturing. This treatment combined with the use of a catalytic agent such as phosphoric acid improved the effects of the texturing effects. This reduced the reflectance of the surface, thereby increased the short circuit current and the conversion efficiency of the solar cell. Employing this technique, we were able to fabricate mc-Si solar cell of 16.4% conversion efficiency with anti-reflective (AR) coating of silicon nitride film using plasma-enhanced chemical vapor deposition (PECVD) and Si wafers can be texturized in a short time.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.184-191
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• 2009

The purpose of this study was to evaluate the physical properties of different self-adhesive resin cements and their shear bond strength on dentin and lithium disilicate ceramic and compare these result with that of conventional resin cement. For this study, four self-adhesive resin cements (Rely-X Unicem, Embrace Wetbond, Mexcem, BisCem), one conventional resin cement (Rely-X ARC) and one restorative resin composite (Z-350) were used. In order to evaluate the physical properties, compressive strength, diametral tensile strength and flexural strength were measured. To evaluate the shear bond strength on dentin, each cement was adhered to buccal dentinal surface of extracted human lower molars. Dentin bonding agent was applied after acid etching for groups of Rely-X ARC and Z-350. In order to evaluate the shear bond strength on ceramic, lithium disilicate glass ceramic (IPS Empress 2) disks were prepared. Only Rely-X ARC and Z-350 groups were pretreated with hydrofluoric acid and silane. And then each resin cement was adhered to ceramic surface in 2 mm diameter. Physical properties and shear bond strengths were measured using a universal testing machine. Results were as follows 1. BisCem showed the lowest compressive strength, diametral tensile strength and flexural strength. (P<0.05) 2. Self-adhesive resin cements showed significantly lower shear bond strength on the dentin and lithium disilicate ceramic than Rely-X ARC and Z-350 (P<0.05) In conclusion, self-adhesive resin cements represent the lower physical properties and shear bond strength than a conventional resin cement.

• Journal of Adhesion and Interface
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• v.25 no.2
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• pp.56-62
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• 2024

In this study, LiDAR-detectable black hollow-structured materials are synthesized using different reducing agents to evaluate their applicability to LiDAR sensor. Initially, white SiO₂/TiO₂ core/shell (WST) materials are fabricated via a sol-gel method, followed by a reduction using ascorbic acid (AA) and sodium borohydride (SB). After the reduction, subsequent etching of the SiO₂ core leads to the formation of two different black hollow-structured materials (AA-BHT and SB-BHT). The lightness (L^*) and near-infrared (NIR) reflectance (R%) of AA-BHT are measured as ca. 19.1 and 34.5 R%, and SB-BHT shows values of ca. 11.5 and 31.8 R%, respectively. While AA-BHT exhibits higher NIR reflectance compared to SB-BHT, it displays slightly lower blackness. Compared with core/shell structured materials, improved NIR reflectance of both AA-BHT and SB-BHT is attributed to the morphology of hollow- structured materials, which increase light reflection at the interface between air and black TiO₂ according to the Fresnel's reflection principle. Consequently, both AA-BHT and SB-BHT are effectively detected by the commercially available LiDAR sensors, validating their suitability as black materials for autonomous vehicle and environment.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.211-221
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• 2010

Proteoglycan is highly hydrophilic and negatively charged which enable them attract the water. The objective of study was to investigate the effects of Proteoglycan on microtensile bond strength of dentin adhesives and on architecture of dentin collagen matrix of acid etched dentin by removing the chondroitin sulphate attached on Proteoglycan. A flat dentin surface in mid-coronal portion of tooth was prepared. After acid etching, half of the specimens were immersed in 0.1 U/mL chondroitinase ABC (C-ABC) for 48 h at $37^{\circ}C$, while the other half were stored in distilled water. Specimens were bonded with the dentin adhesive using three different bonding techniques (wet, dry and re-wet) followed by microtensile bond strength test. SEM examination was done with debonded specimen, resin-dentin interface and acid-etched dentin surface with/without C-ABC treatment. For the subgroups using wet-bonding or dry-bonding technique, microtensile bond strength showed no significant difference after C-ABC treatment (p > 0.05). Nevertheless, the subgroup using rewetting technique after air dry in the Single Bond 2 group demonstrated a significant decrease of microtensile bond strength after C-ABC treatment. Collagen architecture is loosely packed and some fibrils are aggregated together and relatively collapsed compared with normal acid-etched wet dentin after C-ABC treatment. Further studies are necessary for the contribution to the collagen architecture of noncollagenous protein under the various clinical situations and several dentin conditioners and are also needed about long-term effect on bond strength of dentin adhesive.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.275-282
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• 2008

Objective: The purpose of this study was to investigate the effect of using laser for ceramic bracket bonding of porcelain surfaces and to compare it with conventional treatment of porcelain surfaces. Methods: Ninety feldspathic porcelain specimens were divided into 9 groups of 10, with each group having different surface treatments performed. Surface treatment groups were orthophosphoric acid, orthophosphoric acid with silane, hydrofluoric acid, hydrofluoric acid with silane, sandblasted, sandblasted with silane, laser etched, laser etched with silane, and glazed surface served as a control group. In the laser etched groups, the specimens were irradiated with 2-watt superpulse carbon dioxide ($CO_2$) laser for 20 seconds. Ceramic brackets were bonded with light-cure composite resin and all specimens were stored in water at $37^{\circ}C$ for 24 hours. Shear bond strength was determined in megapascals (MPa) by shear test at 1 mm/minute crosshead speed and the failure pattern was assessed. For statistical analysis, one-way ANOVA and tukey test were used. Results: Statistical analysis showed significant differences between the groups. The HFA + S group showed the highest mean shear bond strength ($13.92{\pm}1.94\;MPa$). This was followed by SB + S ($10.16\;{\pm}\;1.27\;MPa$), HFA ($10.09\;{\pm}\;1.07\;MPa$), L + S ($8.25\;{\pm}\;1.24\;MPa$), L ($7.86\;{\pm}\;0.96\;MPa$), OFA + S ($7.22\;{\pm}\;1.09\;MPa$), SB ($3.41\;{\pm}\;0.37\;MPa$), OFA ($2.81\;{\pm}\;0.37\;MPa$), G ($2.46\;{\pm}\;1.36\;MPa$), Bond failure patterns of HFA and silane groups, except L + S, were cohesive modes in porcelain while adhesive failure was observed in the control group and the rest of the groups. Conclusions : A 2-watt superpulse $CO_2$ laser etching of porcelain surfaces can provide a satisfactory result for porcelain surface treatment for ceramic bracket bonding. Laser irradiation may be an alternative conditioning method for the treatment of porcelain surfaces.