MACRO-SHEAR BOND STRENGTH AND MICRO-SHEAR BOND STRENGTH OF CEROMER BONDED TO METAL ALLOY AND FIBER REINFORCED COMPOSITE

Park Hyung-Yoon,Cho Lee-Ra,Cho Kyung-Mo,Park Chan-Jin The Korean Academy of Prosthodonitics 2004 대한치과보철학회지 Vol.42 No.6

Statement of problem. According to the fracture pattern in several reports, fractures most frequently occur in the interface between the ceromer and the substructure. Purpose. The aim of this in vitro study was to compare the macro shear bond strength and microshear bond strength of a ceromer bonded to a fiber reinforced composite (FRC) as well as metal alloys. Material and methods. Ten of the following substructures, type II gold alloy, Co-Cr alloy, Ni-Cr alloy, and FRC (Vectris) substructures with a 12 mm in diameter, were imbedded in acrylic resin and ground with 400, and 1, 000-grit sandpaper. The metal primer and wetting agent were applied to the sandblasted bonding area of the metal specimens and the FRC specimens, respectively. The ceromer was placed onto a 6 mm diameter and 3 mm height mold in the macro-shear test and 1 mm diameter and 2 mm height mold in the micro-shear test, and then polymerized. The macro- and micro-shear bond strength were measured using a universal testing machine and a micro-shear tester, respectively. The macro- and micro-shear strength were analyzed with ANOVA and a post-hoc Scheffe adjustment ($\alpha$ = .05). The fracture surfaces of the crowns were then examined by scanning electron microscopy to determine the mode of failure. Chi-square test was used to identify the differences in the failure mode. Results. The macro-shear strength and the micro-shear strength differed significantly with the types of substructure (P<.001). Although the ceromer/FRC group showed the highest macroand micro-shear strength, the micro-shear strength was not significantly different from that of the base metal alloy groups. The base metal alloy substructure groups showed the lowest mean macro-shear strength. However, the gold alloy substructure group exhibited the least micro-shear strength. The micro-shear strength was higher than the macro-shear strength excluding the gold alloy substructure group. Adhesive failure was most frequent type of fracture in the ceromer specimens bonded to the gold alloys. Cohesive failure at the ceromer layer was more common in the base metals and FRC substructures. Conclusion. The Vectris substructure had higher shear strength than the other substructures. Although the shear strength of the ceromer bonded to the base metals was lower than that of the gold alloy, the micro-shear strength of the base metals were superior to that of the gold alloy.

A Study on Bracket-Adhesive Combinations in Aspect of Shear Bond Strength and Bond Failure

Han, Jae-Ik,Son, Woo-Sung 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.6

적절한 전단접착강도를 가지면서 법랑질손상과 브라켓파절을 적게 일으키는 브라켓-접착제의 그룹을 찾아내기 위하여 전단접착강도, 법랑질손상, 브라켓탈락양상, 브라켓 주위의 밀봉과 법랑질-접착제-브라켓 사이의 긴밀도를 연구하였다. 교정치료목적으로 발치한 240개의 치아를 각각 10개씩 24개 군으로 나누어서 브라켓을 접착한 후 48시간후에 전단접착강도를 측정하고 브라켓 탈락 양상을 조사하였다. 또한 브라켓주위의 밀봉과 법랑질-접착제-브라켓 사이의 긴밀도를 평가하기 위해서 브라켓이 접착된 치아를 반으로 자른후 주사전자현미경상에서 관찰하였다. 6종류의 브라켓과 4종류의 접착제가 사용되었으며 브라켓은 Image, Plastic, Crystaline, Fascination, Transcend, metal bracket을 사용하였으며 접착제로는 No-mix, Light-Bond, OrthoLC, Superbond C&B가 사용되었다. 이와같은 연구로 부터 다음과 같은 결론을 내렸다. 1. 전단접착강도는 Fascination-Light Bond 군에서 36.58Kg(410.07Kg/㎠)으로 가장 높았으며 Image-OrthoLC군에서 8.93Kg(75.51Kg/㎠)으로 가장 낮았다. OrthoLC를 접착제로 사용하였을 때 전단접착강도는 다른 접착제를 사용하였을 때 보다 비교적 낮았다. 2. 접착제의 종류에 관계없이 Fascination bracket의 전단접착강도는 비교적 높았으며 Image, Plastic bracket의 전단접착강도는 비교적 낮았다. Crystaline, Transcond bracket의 전단접착강도는 metal bracket의 전단접착강도와 비슷하거나 낮았다. 3. 전단접착강도와 법랑질 파절, 브라켓 파절은 상관관계가 있었으며, 접착강도가 증가할수록 법랑질 파절과 브라켓 파절은 증가하였다. 4. OrthoLC를 접착제로 사용하였을 때 법랑질 파절과 브라켓 파절은 일어나지 않았으나 Superbond C&B를 접착제로 사용하였을 때는 법랑질 파절과 브라켓 파절의 빈도가 높았다. 5. No-mix, Light-Bond를 접착제로 사용하였을 때 브라켓 주위의 밀봉과 법랑질-접착제-브라켓의 긴밀도는 양호하였다. 접착제의 종류에 관계없이 Ceramic bracket에서 접착제-브라켓의 긴밀도는 양호하였다. 6. 적절한 전단접착강도를 가지면서 법랑질 파절과 브라켓 파절을 일으키지 않은 군은 Crystaline-No mix, Crystaline-Light Bond, Crystaline-OrthoLC, metal-No mix, metal-Light Bond, metal-OrthoLC 군이였다. The purpose of the present study was to seek bracket-adhesive combinations which have adequate bond strength with no enamel and bracket fracture. The shear bond strengths were measured, the sites of failure and the enamel damage were investigated and the peripheral sealing and adaptation between enamel surface, bonging adhesive and bracket were evaluated, 240 noncarious human premolars were divided into twenty four groups of ten teeth. Shear bond strengths of each group were determined in an universal testing machine after two days passed and the debonded specimens were inspected to determine the predominant bond failure sites. To evaluate peripheral sealing and adaption between enamel surface adhesive and bracket, each specimen was cut longitudinally into two halves which included the midsection of the bracket, adhesive and enamel and examined in scanning electron microscope. Six different types of brackets were bonded to the tooth with four different type of adhesives. Six different types of brackets were Image, Plastic, Crystaline, Fascination, Transcend 2000 and metal bracket and four different adhesives were No-mix, Light-Bond, OrthoLC and Superbond C&B. From this study, it may be concluded that(1) The mean shear bond strength varied from a high of 36.58Kg(410.07Kg/㎠) with the Fascination-Light Bond combination group to a low 8.93Kg(75.51Kg/㎠) with the Image-OrthoLC combination group. When using OrthoLC as adhesive, the mean shear bond strength was significantly lower than that of other combination groups, (2) Regardless of adhesives, the mean shear bond strength of Fascination brackets was relatively high whereas Plastic and Image brackets had low shear bonding strength. The shear bond strength of Crystaline bracket and Transcend 2000 was relatively equal to or lower than that of metal bracket, (3) There was a correlation between bond strength, enamel damage and bracket fractrue. As the shear bond strength was increased, the rate of enamel damage and bracket fractrue were increased, (4) The combination groups that use OrthoLC as adhesive were debonded in shear stress without enamel fracture and bracket fracture, whereas the combination groups that use Superbond C&B as adhesive experienced a relative high enamel fracture rate and bracket fracture rate, (5) Peripheral sealing and adaptation between enamel-adhesive-bracket were relatively good when using Light-Bond or No-Mix as adhesive, Regardless of adhesives, adaptation between bracket-adhesive were relatively good in Ceramic brackets, (6) The combination groups which had adequate bonding strength with no enamel and bracket fracture were Crystaline-No mix, Crystaline-Light Bond, Crystaline-OrthoLC, metal-No mix, metal-Light Bond and metal-OrthoLC combination groups.

도재 수리시스템에 따른 도재와 복합레진의 전단결합강도

김경규,신상완,이정렬,김영수,Kim, Kyoung-Kyu,Shin, Sang-Wan,Lee, Jeong-Yeol,Kim, Young-Su 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.4

Purpose: This in vitro study evaluated shear bond strengths of surface treatment porcelains with four porcelain repair systems simulating intraoral bonding of composite resin to feldspathic porcelain or pressable porcelain. Material and methods: Eighty Porcelain disks were prepared. Group A: forty disk specimens were fabricated with Feldspathic Porcelain($Omega^{(R)}900$, Vident, Menlo Park, CA, USA). Group B: forty disk specimens were fabricated with Pressable Porcelain(IPS Empress 2 ingot, Ivoclar-Vivadent, Schaan, Liechtenstein, Germany). Each groups was divided into 4 subgroups and composite resin cylinders were bonded to specimen with one of the following four systems: Clearfil Porcelain Bond(L. Morita, Tustin, CA, USA), Ulradent Porcelain Etch. (Ultradent, Salt Lake City UT, USA), Porcelain Liner-M(Sun Medical Co., Kyoto, Japan), Cimara Kit(Voco, Germany). After surface conditioning with one of the four porcelain repair systems substrate surfaces of the specimen were examined microscopically(SEM). Shear bond strengths of specimens for each subgroup were determined with a universal testing machine (5mm/min crosshead speed) after storing them in distilled water at $37{\pm}1^{\circ}C$ for 24 hours. Stress at failure was measured in $MP_a$, and mode of failure was recorded. Differences among four repair systems were analyzed with two way ANOVA and Duncan test at the 95% significance level. Results: In the scanning electron photomicrograph of the treated porcelain surface, hydrofluoric acid etched group appeared the highest roughness. The shear bond strength of the phosphoric acid etched group was not significantly(p>0.05) different between feldspathic porcelain and pressable porcelain. But in no treatment and roughened with a bur group, the shear bond strength of the feldspathic porcelain was significantly higher than that of the pressable porcelain. In hydrofluoric acid etched group, the shear bond strength of the pressable porcelain was significantly higher(p<0.05). Conclusion: 1. Treatment groups showed significantly greater shear bond strengths than no treatment group(p<0.05). 2. Group with more roughened porcelain surface did not always show higher shear bond strengths. 3. In phosphoric acid etched group, there was no significant difference in shear bond strength between feldspathic porcelain and pressable porcelain(p>0.05). However in the other groups, there were significant differences in shear bond strengths between feldspathic porcelain and pressable porcelain(p<0.05).

교정용 브라켓에 가해지는 힘의 방향에 따른 결합강도의 비교

이현정,이형순,전영미,김정기 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.5

본 연구는 교정용 금속 브라켓에 다양한 방향에서의 복합적인 응력을 가하여 힘의 방향과 적용점에 따른 교정용 브라켓의 결합강도를 비교하고, 브라켓의 유지력을 평가하는데 기준이 되는 최소결합강도의 특성에 대해 알아보고자 시행되었다. 일정한 표면특성을 갖는 금속봉에 Micro-Loc base, Chessboard base, Non-etched Foil-Mesh base 등 서로다른 기저면 형태를 가지는 3가지 종류의 금속 브라켓을 부착시키고, 0˚, 15˚, 30˚, 45˚, 60˚, 75˚, 90˚의 peel 결합강도(_(0)PBS, _(15)PBS, _(30)PBS, _(45)PBS, _(60)PBS, _(75)PBS, _(90)PBS 및 전단결합강도(SBS)와 인장결합강도(TBS)에 대한 브라켓의 결합강도를 측정하고, 각 브라켓의 기저면 면적을 고려하여 단위면적당 결합강도를 산출하여 비교한 결과 다음과 같은 결론을 얻었다. 1. Micro-Loc base와 Chessboard base 및 Non-etched Foil-Mesh base 브라켓 모두에서 전단결합강도(SBS)가 가장 컸다(p<0.01). 2. Peel 응력의 방향 변화에 따른 peel 결합강도(PBS)의 변화양상은 Micro-Loc base와 Chessboard base, Non-etched Foil-Mesh base 브라켓 모두에서 유사하였으며(p>0.05), peel 응력의 적용 각이 증가할수록 peel 결합강도(PBS)는 감소하였고 60˚에서 최저값을 보였다(p<0.05). 3. Micro-Loc base에서 최저 peel 결합강도(_(60)PBS)는 전단결합강도(SBS)의 29% 수준이었으며, 인장결합강도(TBS)에 대해서는 52% 수준이었고, Chessboard base에서 최저 peel bond strength(_(60)PBS)는 전단결합강도(SBS)의 34% 수준이었으며, 인장결합강도(TBS)에 대해서는 61% 수준이었으며, Non-etched Foil-Mesh base에서 최저 peel 결합강도(_(60)PBS)는 전단결합강도(SBS)의 34% 수준이었으며, 인장결합강도(TBS)에 대해서는 55% 수준이었다. 4. 단위면적당 결합강도에 있어서 전단결합강도(SBS)와 인장결합강도(TBS) 및 75˚와 90˚ peel 결합강도는 Micro-Loc base와 Chessboard base에서 차이가 없었으며 Non-etched Foil-Mesh base에서 가장 작았고(p<0.05), 0˚, 15˚, 30˚, 60˚ peel 응력을 적용한 결과 Chessboard base에서 가장 큰 peel 결합강도를, Non-etched Foil-Mesh base에서 가장 작은 결합강도를 보였다(p<0.05). The purpose of this study was to evaluate the bond strength of orthodontic brackets bonded to metal bar with chemically cured adhesive (Ortho-one, Bisco Co, USA) in various types and directions of force application. Three types of metal bracket with different bracket base configurations; Micro-Loc base(Tomy Co, Japan), Chessboard base(Daesung Co, Korea), Non-etched Foil-Mesh base(Dentaurum, Germany); were used in this study. Peel, shear, tensile bond strengths were measured by universal testing machine and compared each other. The peel force directions applied were 0˚, 15˚, 30˚, 45˚, 60˚, 75˚, 90˚. And then, in consideration of the different surface area of the bracket bases, the bond strength per unit area were calculated and compared. The results obtained were summarized as follows : 1. The bond strengths according to the types and the directions of the forces were greatest at the shear forces in all three bracket base configuration groups(p<0.01). 2. As the peel force direction grew higher in degree, peel bond strength decreased. The patterns of peel bond strength change according to force direction was similar in all three bracket base configurations. The minimum bond strength was 60 degree-peel bond strengths in all three bracket base configurations. 3. In Micro-Loc base group, minimum peel bond strength(_(60)PBS) was in 29% level of shear bond strength and 52% level of tensile bond strength. In Chessboard base group, _(60)PBS was in 34% level of shear bond strength and 61% level of tensile bond strength. In Non-etched Foil-Mesh base group, _(60)PBS was in 34% level of shear bond strength and 55% level of tensile bond strength. 4. The bond strengths per unit area were lowest in Non-etched Foil-Mesh base group and highest in Chessboard base group(p<0.05). However, there were no differences in shear bond strength, tensile bond strength, _(75)PBS and _(90)PBS per unit area between Micro-Loc and Chessboard base groups.

도재 및 레진 브라켓에 대한 광중합 접착제의 전단 접착 강도

황유선,노준,황충주 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.2

성인 환자의 증가와 심미적인 장치에 대한 요구가 증가하면서 조재나 레진 브라켓의 사용이 증가되고 있다. 이러한 브라켓에서의 광중합 접착제의 사용은 짧은 광조사 시간에서도 광중합 접착제의 많은 장점을 얻을 수 있다. 이에 본 연구에서는 심미적으로 우수한 수 종의 도재 및 레진 브라켓을 수 종의 광중합 접착제로 접착시켜 전단 접착 강도와 접착 파절 양상을 관찰하였다. 교정 치료를 위해 발거한 140개의 소구치를 협측면이 노출되도록 자가중합 레진으로 매몰하고 소구치 협측면에 Plastic bracket, Transcend 6000, Signature 및 Starfire TMB 브라켓을 Orthobond, Light Bond 및 Transbond로 제조자 지시에 따라 접착시켜 열변환기로 1800회 온도 변화를 준 후 전단 접착 가도를 만능시험기로 측정하고 접착 파절 양상을 입체현미경으로 관찰하였고 10초와 20초의 광조사 시간과 두가지 광원에 대해 전단 접착 강도를 비교하여 다음의 결과를 얻었다. 1. 동일한 브라켓을 Orthobond, Light Bond와 Transbond로 접착시켰을 때 이들간의 전단 접착 강도는 Plastic bracket을 제외하고는 통계학적 유의차가 없었다(P<0.05). 2. 동일한 접착제로 Plastic bracket, Transcend 6000, Signature, Starfire TMB를 접착시켰을 때 이들간의 전단접착 강도는 통계학적 유의차를 보였다(p<0.05). Starfire TMB에서 가장 큰 전단 접착 강도를 보였고 이는 Transcend 6000과 통계학적 유의차가 없었으나 Singnature와는 통계학적 유의차를 보였다(p<0.05). 3. 접착 파절은 전체 군에서 잔루 접착제가 반 이상 또는 모두 치아면에 남은 경우가 72.1%로 대개 브라켓과 접착제 사이에서 파절이 일어났다. 4. 접착제 중합을 위한 광조사 시간은 10초와 20초에서 전단 접착 강도에 통계학적 유의차를 보이지 않았으며 400mW/㎠이상의 광도에서는 서로 다른 광원을 사용해도 전단 접착 강도에 통계학적 유의차를 나타내지 않았다(p<0.05). 이상의 결과로 보아 도재 브라켓의 전단 접착강도는 브라켓 조성과 브라켓 접착면의 유지형태 차이에 의한 영향을 받고 광중합 접착제 종류에 따른 접착 강도의 차이는 나타나지 않았으며 입상에서 브라켓이나 접착제 선택시 이를 고려해야 할 것으로 사료된다. The purpose of this study was to compare the shear bond strength obtained from ceramic and plastic brackets bonded with various light-cured adhesives and to evaluate their debonded failure sites. Plastic brackets, Transcend 6000, Signature and Starfire TMB brackets were bonded with Orthobond, Light Bond and Transbond on one hundred forty extracted human premolar teeth as manufacturer's descriptions. After thermocycling the brackets were debonded with an Instron universal testing machine and the debonded bracket base surfaces were inspected under steroscope to evaluate the failure sites. Also the shear bond strength and failure patterns with different curing time and with two different source of light were compared. The results were as follows. 1. There were no statistically significant differences among the mean shear bond strength of Orthobond, Light Bond and Transbond in a same bracket group except Plastic bracket group(p<0.05). 2. The mean shear bond strength of each adhesive with different bracket groups showed statistically significant differences. Starfire TMB showed the highest shear bond strength among the brackets in this study, but there was no statistically singnificant difference with Transcend 6000 while there was statistically significant difference with Signature.(p<0.05). 3. The various bonding failure patterns were occurred among different bracket groups but most of failure sites were bracket base-adhesive interfaces. 4. There were no statistically significant differences in shear bond strength between the groups with curing time of 10 second and 20 second, and between the groups with two different sources of light as long as sufficient light intensity(above 400mW/㎠) were provided(p<0.05). According to the result, it should be considered in clinical use of ceramic bracket with light-cured adhesives that the shear strengths of ceramic brackets were influenced by the retention from of bracket base as well as the composition of bracket and there was no difference in the shear bond strength among various light-cured adhesives used in this study.

Plasma arc light를 이용한 bracket 부착시의 전단결합강도와 파절양상의 유형

박영철,유형석,오영근,이승연 대한치과교정학회 2001 대한치과교정학회지 Vol.31 No.2

본 연구의 목적은 bracket 부착시 광조사시간을 획기적으로 감소시킬 수 있는 plasma arc licht의 임상적 유용성을 visible light 중합시의 전단결합강도와 접착파절양상과 비교해 봄으로써 평가해 보는데 있다. 사람의 상하악 소구치를 포매하여 만든 레진블럭시편에 광중합 접착제인 TransbondR를 사용하여 수종의 bracket을 각각의 조건에 따라 부착한 후 만능 물성시험기를 이용하여 전단결합강도를 측정하고, 접착파절양상을 stereoscope을 이용하여 관찰하여 다음과 같은 결과를 얻었다. 1.Plasma arc light를 이용한 수종의 bracket 접착시 metal bracket과 ceramic bracket의 전단결합강도는 임상적으로 사용하기에 충분한 값을 나타내었으며, resin bracket의 경우 다른 bracket에 비해 전단결합강도가 현저히 작은 값을 나타내었지만 임상적으로 사용이 가능한 값을 나타내었다. 2.Visible light를 이용한 metal bracket의 광중합시 광조사시 간에 따른 전단결합강도는 광조사 시 간에 따른 유의 한 차이를 보이지 않았으며, 임상적으로 사용하기에 충분한 강도를 나타내었다. 3.Plasma arc light를 이용한 수종의 bracket 접착시 접착제 잔류지수를 통해 접착파절양상을 관찰한 결과, metal bracket과 resin bracket의 경우 bracket기저면에 접착제가 반 이상 남아 있지 않은 경우가 많았으며, ceramic bracket의 경우 bracket기저면에 접착제가 반 이상 남아 있는 경우가 많았다. 4.Metal bracket의 부착시 plasma arc light를 2초간 광조사한 군과 visible light를 10초간 광조사한 군의 전단결합강도와 접착파절양상을 비교시 유의한 차이를 보이지 않았다. 6.Plasma arc light를 이용한 광중합시 광조사 거리에 따른 전단결합강도는 거리가 증가할수록 감소하였다. 이상의 실험 결과는 plasma arc light를 이용한 bracket의 접착시 전단결합강도 저하의 우려 없이 임상적으로 사용 가능함을 시사한다. The puruose of this study was to evaluate the clinical usefulness of plasma arc light which can reduce the curing time dramatically compared by shear bond strengths and failure patters of the brackens bonded with visible light in direct bracket bonding. Some kinds of brackets were bonded with the TransbondR to the human premolars which were embedded in the resin blocks according to the various conditions. After bonding, the shear bond strength was tested by Instron universal testing machine and in addition , the amount of residual adhesive remaining on the tooth after debonding was measured by the stereoscope and assessed with adhesive remnant index(ARI). The results were as follows : 1.When plasma arc light was used for bonding the brackets, the shear bond strength was clinically sufficient in both metal and ceramic brackets, but resin brackets showed significantly lower bond strength but which was clinically useful. 2.When metal brackets were bonded using visible light, there was no significant difference in shear bond strength due to the light-curing time and the bond strength was clinically sufficient. 3.When the adhesive failure patterns of brackets bonded with plasma arc light were observed by using the adhesive remnant index, the bond failure of the metal and resin bracket occurred more frequently at bracket-adhesive interface but the failure of the ceramic bracket occurred more frequently at enamel-adhesive interface. 4.There was no statistically significant difference of the shear bond strength and adhesive failure pattern between metal bracket bonded for 2 seconds by curing with plasma arc light and 10 seconds by curing with visible light. 6.When metal brackets were bonded using plasma arc light, the shear bond strength decreased as the distance from the light source increased. The above results suggest that plasma arc light can be clinically useful for bonding the brackets without fear of the decrease of the shear bond strength.

도재 브라켓의 전단접착강도에 관한 실험적 연구

이승진(Suhng-Jin Lee),장영일(Young-II Chang) 대한치과교정학회 1992 대한치과교정학회지 Vol.22 No.2

The purpose of this study was to evaluate the in vitro shear bond strengths to enamel and the failure sites of three ceramic brackets and one metal bracket in combination with light cured orthodontic adhesive. The brackets were divided into four groups. Each ceramic bracket group had different bonding mechanisms with adhesive. Group A; metal bracket with foil-mesh base (control group) Group B; ceramic bracket with micromechanical retention Group C; ceramic bracket with chemical bonding Group D; ceramic bracket with mechanical retention and chemical bonding. Forty extracted human lower first premolars were prepared for bonding and 10 brackets for each group were bonded to prepared enamel surfaces with Transbond^® light cured orthodontic adhesive. Twenty four hours after bonding, the Instron universal testing machine was used to test the shear bond strength of brackets to enamel. After debonding, brackets and enamel surfaces were examined under stereoscopic microscope to determine the failure sites. Statistical analysis of the data was carried out with ANOVA test and Scheffé test using SPSS PC+. The results were as follows: 1. There were statistically significant differences in mean shear bond strengths of three ceramic bracket groups (p<0.05). Shear bond strengths of group C and D were significantly higher than that of group B and shear bond strength of group C was significantly higher than that of group D. 2. Group C and D both had significantly higher shear bond strengths than metal bracket (group A), but there were no significant differences in shear bond strengths between group A and B (p<0.05). 3. The failure sites of four bracket groups were also different. Group C and D failed primarily at enamel-adhesive interface, but group A and B failed primarily at bracket base-adhesive interface. 4. Among all ceramic bracket groups, group B was very similar to metal bracket in the aspect of shear bond strength and failure site.

DICOR와 G-CERA PORCELAIN LAMINATE VENEER의 전단결합강도에 관한 비교연구

조미숙,양재호,이선형,Cho Mi-Sook,Yang Jae-Ho,Lee Sun-Hyung 대한치과보철학회 1991 대한치과보철학회지 Vol.29 No.3

Cermic has been widely used because of its excellent esthetics and strength. The recently introduced castable ceramic system is regarded as the more esthetic and biocompatible restorative material. The purpose of this study was to compare the shear bond strength of Dicer & G-Cera porcelain laminate veneer according to the type of cement and surface treatment and to observe the surface of bonding failure with SEM. Total forty disks(3.5mm $diam.\times2.0mm$ thickness) were prepared. Forty extracted human maxillary central incisor teeth were stored in saline solution. Ten teeth were bonded to Dicer specimen with Dicer ZPC cement and ten teeth were bonded with Dicer resin cement. Ten silicoated G-Cera specimen and ten non-silicoated G-Cera specimen were bonded to teeth with G-Cera resin cement. Bonded units were mounted in a plastic tube with hard stone and stored in a humidor at $37^{\circ}C$ for 24 hours. Shear bond strength was measured by Instron Universal Testing Machine (Model 1125) and all the specimen were observed with SEM(JEOL, JSM-T2000)and modes of failure were recorded. The obtained results were as follows: 1. The mean shear bond strength of Dicer bonded with Dicer resin cement was 11.62 MPa and that bonded with Dicor ZPC cement was 0.88 MPa : Shear bond strength of Dicer bonded with Dicer resin cement was significantly increased(P<0.05). 2. The mean shear bond strength of silicoated G-Cera was 13.10 MPa and that of non silicoated G-Cera was 10.93 MPa : Shear bond strength of silicoated G-Cera was not significantly increased (P>0.05). 3. Shear bond strength of Dicer and G-Cera porcelain laminate veneer was not significantly different (P>0.05). 4. In observation of bond failure with SEM, Dicer bonded with Dicer ZPC cement exhibited adhesive failure. Dicer bonded with Dicer resin cement and silicoated and non silicoated G-Cera exhibited cohesive failure.

The effect of repeated bonding on the shear bond strength of different resin cements to enamel and dentin

Ali Can Bulut,Saadet Sağlam Atsü 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.1

PURPOSE. Cementation failures of restorations are frequently observed in clinical practice. The purpose of this study is to compare the effect of initial and repeated bonding on the bond strengths of different resin cements to enamel and dentin. MATERIALS AND METHODS. Ninety human maxillary central incisors were bisected longitudinally. The 180 tooth halves were divided into 2 groups (n = 90) for enamel and dentin bonding. The enamel and dentin groups were further divided into 3 groups (n = 30) for different resin cement types. Composite resin (Filtek Ultimate) cylinders (3 × 3 mm) were prepared and luted to enamel and dentin using Variolink II (Group V), RelyX ARC (Group R), or Panavia F 2.0 (Group P) resin cement. After 24 hours, initial shear bond strengths of the resin cements to enamel and dentin were measured. Using new cylinders, the specimens were de-bonded and re-bonded twice to measure the first and the second bond strengths to enamel and dentin. Failure modes and bonding interfaces were examined. Data were statistically analyzed. RESULTS. Initial and repeated bond strengths to enamel were similar for all the groups. The first (15.3 ± 2.2 MPa) and second (10.4 ± 2.2 MPa) bond strengths to dentin were significantly higher in Group V (P<.0001). Second bond strengths of dentin groups were significantly lower than initial and first bond strengths to dentin (P<.0001). CONCLUSION. All resin cements have similar initial and repeated bond strengths to enamel. Variolink II has the highest first and second bond strength to dentin. Bond strength to dentin decreases after the first re-bonding for all resin cements.

재생 브라켓의 전단접착강도에 관한 비교 연구

서정훈,최은아 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.4

본 연구는 열을 이용한 금속 브라켓의 재생 처리시, 기저부 형태와 브라켓 재생 방법에 따른 전단접착강도 및 브라켓 탈락 양상을 비교하고자 시행되었다. 교정 치료를 위해 발거된 건전한 소구치 252개를 수집하고, Type I, Type II, Type III 스탠다드 브라켓을 각각 재생 방법에 따라 네 군으로 나누어 준비된 소구치에 접착하고, Instron Universal Testing Machine(Model 4466)으로 전단접착강도를 측정하였으며, 브라켓의 타락 양상을 관찰하고 브라켓 기저부의 주사전자현미경 소견을 관찰하였다. SP SS 통계처리 프로그램을 이용하여 일원분산분석(oneway ANOVA), Scheffe`s multiple range test를 실시하여 다음과 같은 결론을 얻었다. 1. 브라켓 기저부 형태에 따른 전단접착강도는 유의차가 있었으며(P<0.001), 그 크기는 Type III(round indentation, micro-etched base), Type I(foil-mesh base), Type II(grooved integral base, micro-etched)의 순이었다. 2. 재생 방법에 따른 전단접착강도는, Type I, Type II 브라켓에서는 Big Jane에 1분간 처리시 우수한 결과를 보였고(p<0.05), Type III 브라켓에서는 각 군간 유의한 차이를 보이지 않았다.(p>0.05). 3. Type I, Type II 브라켓은 기저부-레진 계면에서 가장 높은 빈도로 탈락하였고, Type III 브라켓에서는 레진의 절반가량이 치면에 잔존하는 탈락 양상이 가장 많았다. 4. 탈락 양상에 따라 탈락시의 전단접착강도가 유의성 있는 차이를 보였는데(p<0.05), 브라켓 탈락시 접착제의 절반가량이 치면에 잔존하는 경우 전단접착경우가 가장 큰 것으로 나타났다. 5. 브라켓 재생 후 기저부에 남아 있는 접착제는 전단접착강도의 감소에 영향을 미치지 않았다. This study was undertaken to compare the bond strength and the fracture site of new and recycled brackets according to the base design. 252 sound premolars extracted for orthodontic treatment were collected, and Type I, Type II, Type III brackets were divided into four groups by recycling method. Each bracket was then bonded to an extracted premolar. Instron Universal Testing Machine(model 4466) was used to measure the shear bond strength, and the surface of the recycled brackets were viewed in SEM. For the analysis of the results, one way ANOVA and Scheffe`s multiple range test was executed using the SPSSWIN program. 1. The shear bond strength showed statistically significant difference according to the bracket base design (P<0.001). Type III bracket(round indentation base, micro-etched) showed the highest bond strength, Type I bracket(foil-mesh base) was second, and Type II bracket(grooved integral base, micro-etched) was last. 2. The effect of recycling on the bond strength was different according to bracket type. The shear bond strength of Type I, Type II brackets showed the smallist reduction when treated for 1 minute in Big Jane(p<0.05), but the shear bond strength of Type III brackets showed no statistically significant difference according to recycling method(p>0.05). 3. In Type I, Type II brackets, frequent fracture site was bracket-resin interface, but in Type III brackets, about half of the resin was retained on the tooth surface frequently. 4. The shear bond strength was highest when about half of the resin was retained on the tooth surface(p<0.05). 5. The resin remnant on the bracket base after recycling had no effect on the shear bond strength.