• The korean journal of orthodontics
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• v.41 no.2
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• pp.121-126
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• 2011

Objective: The purpose of this study was to evaluate shear bond strength (SBS) and failure site location of brackets bonded to enamel with or without desensitizer application. Methods: Sixty-six freshly extracted human premolar teeth were randomly divided into 3 groups of 22. Group 1 served as the control. Desensitizer was applied to the remaining teeth at two time intervals (Group 2, bonded immediately after Pro-$Relief^{TM}$ (Colgate-Palmolive Co., New York, NY, USA) application and Group 3, bonded 30 days after Pro-$Relief^{TM}$ application with the teeth stored in artificial saliva during the 30 days). Orthodontic brackets were bonded with a light cure composite resin and cured with a halogen light. After bonding, the SBS of the brackets was tested using a universal testing device. Adhesive remnant index (ARI) scores were determined after the brackets failed. Data were analyzed with analysis of variance, Tukey's HSD, and G tests. Results: The SBS was significantly lower in Group 2 than in Groups 1 (p = 0.024) and 3 (p = 0.017). Groups 1 and Group 3 did not differ (p = 0.991). ARI scores did not differ significantly among groups. Conclusions: The Pro-$Relief^{TM}$ desensitizer agent applied immediately before bonding significantly reduces bond strength, but the SBS values still exceed the minimum 5.9 - 7.8 MPa required for adequate clinical performance. Immersing the teeth in artificial saliva for 30 days after applying the Pro-$Relief^{TM}$ desensitizer agent and before bonding increased the SBS to control levels.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.3
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• pp.249-256
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• 2015

Restorative dental materials have advanced rapidly, with improved physical properties that improve survival rates. Accordingly, various materials can be selected. Amalgam, composite resin, glass-ionomer cement, and preformed stainless steel crowns have all been used widely for the restoration of dental caries in primary molars. The various dental materials used to treat proximal caries in the primary molars have distinct advantages and disadvantages. However, few studies have examined their survival rates. This retrospective study examined the 2-year survival rates of more than 700 class II restorations of proximal caries in primary molars clinically and radiologically according to the type of restoration. The study results should help in the selection of class II restorations for molars, one of the biggest concerns of pediatric dentists.

• Restorative Dentistry and Endodontics
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• v.40 no.4
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• pp.299-305
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• 2015

Objectives: The purpose of this study was to investigate the effectiveness of multiple decontamination procedures for salivary contamination after curing of a universal adhesive on dentin bond strength according to its etch modes. Materials and Methods: Forty-two extracted bovine incisors were trimmed by exposing the labial dentin surfaces and embedded in cylindrical molds. A universal adhesive (All-Bond Universal, Bisco) was used. The teeth were randomly divided into groups according to etch mode and decontamination procedure. The adhesive was applied according to the manufacturer's instructions for a given etch mode. With the exception of the control groups, the cured adhesive was contaminated with saliva for 20 sec. In the self-etch group, the teeth were divided into three groups: control, decontamination with rinsing and drying, and decontamination with rinsing, drying, and adhesive. In the etch-and-rinse group, the teeth were divided into four groups: control, decontamination with rinsing and drying, decontamination with rinsing, drying, and adhesive, and decontamination with rinsing, drying, re-etching, and reapplication of adhesive. A composite resin (Filtek Z350XT, 3M ESPE) was used for filling and was cured on the treated surfaces. Shear bond strength was measured, and failure modes were evaluated. The data were subjected to one-way analysis of variation and Tukey's HSD test. Results: The etch-and-rinse subgroup that was decontaminated by rinse, drying, re-etching, and reapplication of adhesive showed a significantly higher bond strength. Conclusions: When salivary contamination occurs after curing of the universal adhesive, additional etching improves the bond strength to dentin.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.85-93
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• 1986

The purpose of this study was to investigate the curing effect of visible light through tooth substance, 0.5mm, 1.0mm thickness of enamel and dentin were prepared. Experimental specimen were made by Bisfil M & Silux packing into cylindrical brass mold 6.0mm in diameter, 2.0mm and 3.0mm, in height. All specimen were irradiated by visible light (Grip type) model No. SDL-50 Shofu Co.) for 30 seconds through tooth substance. Experimental groups were classified into enamel group (group 1) and dentin group (group 2) according to the thickness of tooth materials and then were divided into 2 subgroups (0.5mm group and 1.0mm group). In experimental groups, visible light irradiated to the specimen through either 0.5mm in thick or 1.0mm in think of tooth material. In Control group specimen were prepared by direct irradiation on the specimen surface of visible light without through tooth substance. The hardness was measured with a Barcol hardness tester (Barber-Colman Co. U.S.A.) for each prepared specimen. The results were as follows: 1. In control group, there were higher hardness values than those of in experimental group. 2. In experimental groups, 0.5mm groups had higher hardness values than 1.0mm groups did. 3. The hardness value at top surface of the specimen were higher than the hardness of bottom surface in each group. 4. Bisfil M had higher hardness values than Silux. 5. In all specimen of 3.0mm height polymerization effect was not occurred at bottom surface except Bisfil M in control group.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.326-331
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• 2001

목적 - 최근 복합레진의 미세변연누출을 줄이기 위한 새로운 광중합 조사방법이 연구되고 있다. 또한 구치용 복합레진이 개발되면서 그 제조회사에서는 5mm 깊이까지 광중합이 가능하다고 소개하고 있다. 본 연구에서는 논리적 가설에 근거한 몇가지 광중합 조사방법이 구치부 class II 와동의 복합레진 충전시 미세변연누출에 어떠한 영향을 미치는지를 관찰하였다. 재료 및 방법 - 100개의 우식증이 없는 사람의 상하악 대구치를 사용했다. 각 치아에 교합-치은방향으로 4mm, 협설 4mm, 깊이 2mm의 class II 와동을 형성하여 인접치와 함께 베이스플레이트 왁스에 매몰하고 구치용 복합레진인 Surefil을 제조 회사의 지시대로 충전하였다. 이때 5가지의 광조사방법을 이용하여 5개의 군으로 나누어 중합하였다(Table 1). 수복된 치아들을 5$^{\circ}C$와 55$^{\circ}C$의 수조에서 번갈아 1분씩 총 500회의 온도변화를 주어 thermocycling을 실시한 후 근첨을 폐쇄하고 수복와동의 치은경계를 제외한 전 표면에 nail varnish를 2회 도포하였다. 2%의 methylene blue용액에 24시간 침적시키고 흐르는 물에 세척한 후 시편을 투명한 에폭시 레진에 매몰하였다. 매몰된 시편을 치아 장축에 평행하게 절단 연마하였다. 입체 현미경으로 미세변연누출을 관찰하고 Kruskal-Wallis One Way ANOVA 와 Dunn's Method로 통계처리 하였다. 결과 - 1. 미세누출은 1군, 4군과 5군, 2군 3군 순으로 증가였다. 이때 1군, 4군과 5군은 통계적 유의성이 없었다(P>0.05). 2. 2군의 경우 1군, 4군, 5군에 비교하여 유의성 있게 미세누출이 많았으며(P<0.05) 3군에 비하여 유의성 있게 적게 나타났다(P<0.05). 3. 3군의 경우 다른 방법들에 비교하여 통계적으로 유의성 있게 미세누출이 많았다(P<0.05).

• Restorative Dentistry and Endodontics
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• v.37 no.1
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• pp.9-15
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• 2012

Objectives: This study evaluated the effect of 2% chlorhexidine digluconate (CHX) with different application times on microtensile bonds strength (MTBS) to dentin in class I cavities and intended to search for ideal application time for a simplified bonding protocol. Materials and Methods: Flat dentinal surfaces with class I cavities ($4mm{\times}4mm{\times}2mm$) in 40 molar teeth were bonded with etch-and-rinse adhesive system, Adper Single Bond 2 (3M ESPE) after: (1) etching only as a control group; (2) etching + CHX 5 sec + rinsing; (3) etching + CHX 15 sec + rinsing; (4) etching + CHX 30 sec + rinsing; and (5) etching + CHX 60 sec + rinsing. Resin composite was builtup with Z-250 (3M ESPE) using a bulk method and polymerized for 40 sec. For each condition, half of the specimens were immediately submitted to MTBS test and the rest of them were assigned to thermocycling of 10,000 cycles between $5^{\circ}C$ and $55^{\circ}C$ before testing. The data were analyzed using two-way ANOVA, at a significance level of 95%. Results: There was no significant difference in bond strength between CHX pretreated group and control group at the immediate testing period. After thermocycling, all groups showed reduced bond strength irrespective of the CHX use. However, groups treated with CHX maintained significantly higher MTBS than control group (p < 0.05). In addition, CHX application time did not have any significant influence on the bond strength among groups treated with CHX. Conclusion: Application of 2% CHX for a short time period (5 sec) after etching with 37% phosphoric acid may be sufficient to preserve dentin bond strength.

• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.153-161
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• 2004

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength(${\mu}TBS$). Human molars were sectioned to expose the superficial dentin surfaces. Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (0)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D), blot dry (BD) or dry for 15s, and rewet with different rewetting agents [distilled water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)] for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with $1\textrm{mm}^2$ cross sectional area and the ${\mu}TBS$ was determined by EZ test. In the S group, the mean ${\mu}TBS$ of GD, AP, and BD group was significantly higher than that of DW and D group (p < 0.05), In the O group, the mean, ${\mu}TBS$ of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05). The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.585-601
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• 1996

The purpose of this study was to elucidate the effect of blood-and saliva-contamination during dentin pretreatment procedure on tensile bond strength, and to investigate the effect of contaminant-removing treatments on the recovery of bond strength of dentin bonding agents. Dentin specimens prepared from freshly extracted bovine mandibular anterior teeth were divided into non-contaminated control and contaminated experimental groups. The specimens of the contaminated group were contaminated with saliva or blood after etching or priming procedure, followed by contaminant-removing treatments. All the specimens were bonded with All Bond$^{(R)}$ 2 dentin bonding agent and Bisfil$^{TM}$ composite resin or Scotchbond$^{TM}$ Multipurpose and Z100. After all the bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, tensile bond strengths were measured. The contaminated dentin and fractured dentin surfaces were examined under the scanning electron microscope. The results were as follows : Contaminated specimens showed lower bond strength than non-contaminated ones regardless of the kind of contaminant, contamination time and contaminant-removing treatments, except specimens which were acid-etched following saliva contamination after etching in All Bond$^{(R)}$ 2 groups (p<0.05). Blood contaminant resulted in much bond strength decrease than saliva ones (p<0.01), and contamination after priming resulted in much decrease in bond strength than after etching (p<0.01). Re-etching resulted in increase of bond strength in the specimens contaminated with saliva after etching but not in blood contaminated ones. Re-priming resulted in increase of bond strength in the specimens contaminated after priming regardless of the kind of contaminant.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.111-118
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• 2019

Post-endodontic restorations are both important and challenging for clinical success in endodontically treated posterior teeth. Several options have been proposed to restore endodontically treated molars. In pediatric dentistry, restoration using conventional single crowns, especially for partially erupted molars with insufficient retentive tooth structure, has proven to be difficult. However, the endocrown presents a conservative and esthetic restorative alternative to conventional crowns with post-and-core, as it acquires additional retention within the pulp chamber. The tooth preparation consists of a circular, equigingival, butt-joint margin and a central retention cavity in the pulp chamber that helps to construct both the crown and core as a single unit. This case report describes the esthetic and conservative endocrown restorations of erupting permanent first molars with extensive coronal destruction.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.3.1-3.14
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• 2021

Objectives: This study aimed to evaluate the interface between a calcium silicate cement (CSC), Biodentine and dental adhesives in terms of sealing ability. Materials and Methods: Microleakage test: 160 standardized class II cavities were prepared on 80 extracted human molars. The cavities were filled with Biodentine and then divided into 2 experimental groups according to the time of restoration: composite resin obturation 15 minutes after Biodentine handling (D0); restoration after 7 days (D7). Each group was then divided into 8 subgroups (n = 5) according to the adhesive system used: etch-and-rinse adhesive (Prime & Bond); self-etch adhesive 2 steps (Optibond XTR and Clearfil SE Bond); self-etch adhesive 1 step (Xeno III, G-aenial Bond, and Clearfil Tri-S Bond); and universal used as etch-and-rinse or self-etch (ScotchBond Universal ER or SE). After thermocycling, the teeth were immersed in a silver nitrate solution, stained, longitudinally sectioned, and the Biodentine/adhesive percolation was quantified. Scanning electron microscopic observations: Biodentine/adhesive interfaces were observed. Results: A tendency towards less microleakage was observed when Biodentine was etched (2.47%) and when restorations were done without delay (D0: 4.31%, D7: 6.78%), but this was not significant. The adhesives containing 10-methacryloyloxydecyl dihydrogen phosphate monomer showed the most stable results at both times studied. All Biodentine/adhesive interfaces were homogeneous and regular. Conclusions: The good sealing of the CSC/adhesive interface is not a function of the system adhesive family used or the cement maturation before restoration. Biodentine can be used as a dentine substitute.