• 대한치과의사협회지
• /
• 제58권7호
• /
• pp.413-434
• /
• 2020

Recently, there are much improvement in optical and mechanical properties of dental ceramic materials coupled with improved fabrication techniques, which have caused a considerable shift in the preference of the dentists to ceramic restorations. Because the chemical composition and microstructure of all-ceramic materials are different by the type, correct choice of cement type and surface treatment procedure, and cementation strategy is essential for the success of ceramic restorations with adequate retention and decreased incidence of complications. This manuscript reviews on the most often prescribed and some newly developed ceramic materials, and the selection criteria and usage guidelines of cement materials that are used in conjunction with various ceramic materials. This manuscript emphasizes that continuous updating the information of newly developed ceramic and cement materials and application techniques by the dentists and dental staffs are demanding in response to the constantly improving ceramic and cement materials and corresponding application protocol changes.

• Journal of Korean Dental Science
• /
• 제11권1호
• /
• pp.14-20
• /
• 2018

Purpose: The purpose of this study is to measure and compare the removal torques of different cements applied in attachments of zirconia restorations on titanium (Ti) abutments fitted with retrievable cement-type slot (RCS) on the lingual side for the better retrievablity by use of a slot driver. Materials and Methods: Three types of cements were used in the experiment: two permanent cements in $RelyX^{TM}$ U200 (RU) (3M ESPE) which is a resin cement and $FujiCem^{TM}$ (FC) (GC) which is a resin-modified glass ionomer cement, and a temporary cement in $Freegenol^{TM}$ temporary cement (TC) (GC). Measurements of removal torques were conducted as follows; an attached sample was fixed on the equipment customized for the experiment; a slot driver was connected to a MGT12 (Mark-10 Corp.), a torque measurement instrument; the sample had the driver fitted to its RCS and then was rotated until the it was removed; and finally, the maximum torque value was recorded. Result: As for the removal torque measurement results, the average values were $47.9{\pm}2.6Ncm$ for RU, $43.4{\pm}1.5Ncm$ for FC, and $20.9{\pm}1.0Ncm$ for TC. The statistical analysis using Kruskal-Wallis test yielded the significance probability of P<0.05 (P=0.002), which confirmed the presence of significant differences between the three groups. Conclusion: All three cements exhibit clinically acceptable levels of removal torque when applied to an upper zirconia implant restoration fitted with a lingual slot, with RU and FC, the two permanent cements, having the significantly higher values than that of TC, the temporary cement.

• 대한화학회지
• /
• 제62권2호
• /
• pp.93-98
• /
• 2018

Bis-GMA, TEGDMA, and camphorquinone were used as the main material, cross-linking agent, and photoinitiator, respectively. In addition, 2-isocyanatoethyl methacrylate was used as an additive for high strength, while the 3-hydroxypyridine was used as an additive for antibacterial activity. Photopolymerization was also carried out at a 440-480 nm wavelength and at about $1000mW/cm^2$ intensity for about 40 seconds. The breaking strength measurement of the samples showed that the breaking strength increased along with increasing the addition ratio of IEM, while it took less time until the polymerization was complete, thereby suggesting that the degree of polymerization has the tendency to increase. And also, compared to the size of the clear zone formed by ampicillin, the 3-hydroxypyridine group exhibited antimicrobial activity induced by ampicillin. The results of this study suggest that the use of 2-isocyanatoethyl methacrylate as an additive for high strength and 3-hydroxypyridine as an additive for improved antibacterial activity would improve the usability of the fabricated polymer as a dental resin cement material with high functionality.

• 대한치과보철학회지
• /
• 제38권2호
• /
• pp.169-177
• /
• 2000

The purpose of this study was to compare the retention of complete cast crown over amalgam ores, composite resin cores, and cast gold cores when cemented with three different luting agents. Eighteen core specimens each of amalgam(Bestaloy, Dong Myung, Seoul, Korea), composite resin (Z100, 3M Dental product, st. Paul, Minn) and type IV gold alloy (Ba-4, Heesung Engelhard Corp., Korea) were made in a customized milling stainless steel die. A wax pattern with a loop attached to occlusal surface was made for each core and a type II gold alloy casting was fabricated. The castings which had clinically acceptable marginal fit were used as test samples. The following luting cements were used to cement cast crowns on each core material : (1) zinc phosphate cement (Confi-dental Products Co., USA) (2) glass-ionomer cement (Fuji Plus, GC Industrial Corp., Tokyo, Japan) (3) resin cement (Panavia 21, Kuraray Co., USA). All cements were mixed according to manufacturers' instructions. A static load of 5kg was then applied for 10 minutes on the crowns. All specimens were stored in saline solution for 24 hours at $37^{\circ}C$ and thermocycled for 500 cycles. After storage and cycling, the tensile bond strengths were measured by using a universal testing machine (Instron Corp., Canton, Mass.) at a crosshead speed of 0.5mm/min. The results were as follows 1. The retentive strength of resin cement was the highest of alt three types of cement for resin core (p<0.05). 2. There was no statistical difference among the retentive strengths of three cements for amalgam core (p>0.05). 3. The retentive strength of resin cement was higher than that of zinc phosphate for cast core, but there was no difference between the retentive strength of glass ionomer cement and those of rein and zinc phosphate cement. 4. The retentive strength of the zinc phosphate cement for amalgam core was the highest of all type of cores.

• 대한소아치과학회지
• /
• 제24권2호
• /
• pp.436-448
• /
• 1997

Topical fluoride application for children is a widely performed procedure in the field of Pediatric Dentistry for its dental caries prevention effects. However, it is recently recognized as having some unwanted effects on several esthetic restorative materials as it roughens the surfaces of the restorative materials. In order to evaluate the surface changes in esthetic restorative materials, the author immersed composite resin, glass ionomer cement, and resin-modified glass ionomer cement specimens in various topical fluoride agents and measured the weight loss and also, examined the specimens under the scanning electron microscope. The followings are the results : 1. All the specimens immersed in APF gel for 4 minutes showed statistically significant weight loss. (paired t-test, P<0.05). 2. There was no statistically significant weight loss for the resin-modified glass ionomer cement and composite resin groups immersed in sodium fluoride solution (paired t-test, P>0.05). 3. When the glass ionomer cement group was immersed in APF gel for 1 and 4 minutes, there was a statistically significant weight loss compare to other esthetic restorative materials (ANOVA, P<0.05). 4. In the resin-modified glass ionomer cement group and the composite resin group, weight loss in the APF gel 4 minutes immersion group was greater than the 1 minute immersion group, and it was statistically significant (ANOVA, P<0.05). 5. When the specimens were examined under scanning electron microscope, the surface changes were greatest in the order of glass ionomer cement, resin-modified glass ionomer cement, composite resin and also in the order of APF gel 4 minute immersion group, 1 minute immersion group, sodium fluoride immersion group, and control group.

• 대한치과보철학회지
• /
• 제37권5호
• /
• pp.658-671
• /
• 1999

The major influencing factors on the strength of all-ceramic crowns are types of dental ceramics, fabrication techniques, methods of abutment preparation and cementation modes of all-ceramic restorations. Zinc phosphate cement and glass-ionomer cement were used as an early lot-ing media for all-ceramic crowns. Recently many studies have reported that resin cements have more advantages in increasing the fracture strength of restorations comparing with zincphosphate cement and glass-ionomer cement. The purpose of this study is to investigate the effect of etching, silane treatment, sandblasting and dentin bonding agents on fracture strengths of dental ceramics. 40 flat dentin specimens and 40 ceramic discs of 1.5mm thickness and 8mm diameter were fabricated, and divided into 4 groups according to surface treatments. Surface treatments before cementation were as follows Group I : (ceramic) : HF etching - silane treatment - application of bonding resin (dentin) : application of dentin bonding agent Group II : (ceramic) : sandblasting - application of bonding resin (dentin) : application of dentin bonding agent Group III : (ceramic) : application of bonding resin (dentin) : application of dentin bonding agent Group IV : (ceramic) : HF etching - silane treatment - application of bonding resin (dentin) : no dentin bonding procedure Dentin specimens and ceramic discs were cemented with dual cure resin cement, and went through thermocycling. Compressive stress es were loaded on the centers of ceramic discs with Instron test-ing machine, and fracture strengths resistance for catastrophic fracture were measured The results were as follows. 1. The group I showed the highest fracture resistance. The next was group II And group III, IV followed. 2. There was a significant difference in the mean value of fracture strengths between group I and group III (p<0.05), but no significant differences between group I and group II, and group II and group III (p>0.05). 3. There was a significant difference in the mean value of fracture strengths between group I and group IV (p<0.05).

• Restorative Dentistry and Endodontics
• /
• 제20권1호
• /
• pp.129-141
• /
• 1995

Composite resin and glass-ionomer cement can be used for the purpose of repair of defective amalgam restoration. The purpose of this study was to evaluate of shear bond strength of esthetic restorative materials to dental amalgam. The materials used in this study were Photo Clearfil Bright(light curing composite resin), Clearfil F II(chemical curing composite resin), Fuji II LC(light curing glass-ionomer cement), Fuji II (chemical curing glass-ionomer cement), All-Bond 2(intermediary), and Scotchbond Multi-Purpose (intermediary). A total of 120 acrylic cylinders with amalgam were divided into 8 groups After amalgam condensation, all specimens were stored for 48 hours in water at $37^{\circ}C$ and tested with Instron universal testing machine between amalgam and composite resins and glass-ionomer cements. The data were analyzes statiscally by ANOVA and Duncan test. The following results obtained ; 1. The shear bond strength of bonded composite resin to amalgam was higher than bonded glass-ionomer cement(P<.001). 2. The group 4 had highest shear bond strength with 15.45kgf/$cm^2$ and the group 5 had lowest shear bond strenght with 3.26kgf/$cm^2$(P<.001). 3. In the group 3, 4, 5, 6, the group 3, 4 with All-Bond 2 had higher shear bond strength than the group 5, 6 with Scotch bond MP both in light-curing and in chemical curing. 4. Both in composite resin and glass-ionomer cement, chemical curing materials had higher shear bond stength than light curing materials(P<.001).

• 대한치과의사협회지
• /
• 제53권3호
• /
• pp.195-200
• /
• 2015

Cementation is the last procedure and an important factor to access successful fixed prosthodontic treatment. Even though there are many kinds of luting materials in dental field, the resin cements are popularly used in now. Metals, polymers and ceramics are used as a material of fixed dental prosthesis. The bonding mechanisms between teeth and fixed restorations are composed of mechanical and chemical mechanism. In dentistry, we are relying on mechanical bonding, but we tried to get chemical bonding and many ways are introduced. So, we have to approach luting procedure differently by the materials of prosthesis for clinical success. In this article, let us think the proper cementation ways according to each prosthesis material.

• 대한치과보철학회지
• /
• 제51권1호
• /
• pp.27-32
• /
• 2013

연구 재료 및 방법: 본 연구에서는 간접 레진 수복시에 상아질 접착제와 저점도 레진을 이용한 상아질 레진코팅법을 자가 접착 레진 시멘트에 적용해 전단결합강도가 증가하는지 비교하고 기존의 레진 시멘트와의 전단결합강도 차이가 어떠한지 평가하고자 하였다. 연구 목적: 사람의 발거된 건전한 구치 36개의 치관부를 삭제하고 상아질을 노출시킨 후 3개의 군으로 분류하였다. 1군과 3군은 상아질에 아무런 처리 과정을 거치지 않고 2군만 Clearfil SE bond와 Metafil Flo를 사용해 상아질 레진코팅법을 시행하였다. 24시간의 임시수복 기간을 둔 후 Tescera를 이용하여 제작한 레진 인레이 블록을 1군과 2군에는 Unicem, 3군에는 Panavia F를 사용해 접착하였다. 그 후 증류수에 48시간 동안 보관한 후 전단결합강도를 측정하였다. 측정된 전단결합강도는 one-way ANOVA를 이용하여 비교 분석하였으며 유의한 차이가 있는 경우 Tukey method를 이용하여 multiple comparison를 시행하였다. 결과:상아질에 레진코팅법을 시행한 경우의 Unicem의 결합강도가 상아질에 아무런 처리를 하지 않은 대조군의 결합강도보다 높게 나타났고(P<.0001), 레진코팅을 하지 않고 Panavia F로 접착한 실험군의 결합강도보다 높게 나타났다(P<.0001). 결론: 상아질 레진코팅법은 자가 접착 레진 시멘트의 접착 강도를 증가시켰다.

• The Journal of Advanced Prosthodontics
• /
• 제5권2호
• /
• pp.126-132
• /
• 2013

PURPOSE. Post surface conditioning is necessary to expose the glass fibers to enable bonding between fiber post and resin cement. The purpose of the present study was to evaluate the effect of different surface conditioning on tensile bond strength (TBS) of a glass fiber reinforced post to resin cement. MATERIALS AND METHODS. In this in vitro study, 40 extracted single canal central incisors were endodontically treated and post spaces were prepared. The teeth were divided into four groups according to the methods of post surface treatment (n=10): 1) Silanization after etching with 20% $H_2O_2$, 2) Silanization after airborne-particle abrasion, 3) Silanization, and 4) No conditioning (Control). Adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber posts to the root canal dentin. Three slices of 3 mm thick were obtained from each root. A universal testing machine was used with a cross-head speed of 1 mm/minute for performing the push-out tests. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (${\alpha}$=0.05). RESULTS. It is revealed that different surface treatments and root dentin regions had significant effects on TBS, but the interaction between surface treatments and root canal regions had no significant effect on TBS. There was significant difference among $H_2O_2$ + Silane Group and other three groups. CONCLUSION. There were significant differences among the mean TBS values of different surface treatments. Application of hydrogen peroxide before silanization increased the bond strength between resin cements and fiber posts. The mean TBS mean values was significantly greater in the coronal region of root canal than the middle and apical thirds.