Jourtial of Otal Rehabilitation, 1992. Volume 19. pages 457-469
Microleakage of indirect inlays placed on different kinds of glass ionomer cement linings L. KARAAGACLIOGLU, A, ZAIMOGLU am/ A,C. AKOREN Depattment of Prosthodontics, Faculty of Detttistry, University of Ankata.
Turkey
Summary The objective of this study is to compare the marginal seal of Class II eavities r'estored with indirect inlays constructed on glass ionomer cement linings having different curing pr'operties. Also the effect of acid-etching of these liners on microleakage was investigated. Mesio-occlusal and disfo-occlusal cavities in 80 extracted human molars having the cervical lloor below the cernetitoenamel junctioti were prepared (/i;160). Half of the preparations were restored with Ceramco II® porcelain and the rest with SR-Isosit® resin inlay material. Liners as light curing Ionoseal® light-l-chetnieally curing LCL 8® and Zionomer® and chernieally curing Ketac-Bond® glass ionomer cements (GICs) were used. On mesial preparations GICs were acid-etched but were not on distal preparations. All inlays were cemented with Ultrabond® composite material. After thermocycling the teeth were placed in a basic fuchsin dye solution for 24 h, then each tooth was sectioned. By using a stereornicroscope the extent of marginal leakage was scored and statistically evaluated. Mieroleakage was observed beneath all GIC linings and was more extensive between light curing GlC/dentine interface. By acid-efching of GICs the microleakage between GlC/dentine interfaee was increased significantly. Whether acid-etching was applied or not a significantly increased microleakage was recorded between chemieally curing GlC/composife interfaees. Although the marginal microleakage was witnessed in both inlays, it appeared that poreelain inlays provided a better tnarginal seal, in comparison to SR-Isosit inlays. Introduction Although, the physieal properties of recently introduced composite resins have been improved, polymerization shrinkage and the results of this continue to affect the longevity of direct posterior resin restorations (Bauer & Hanson, 1984). Polymerization shrinkage causes marginal gaps and then leakage especially, when the border of the preparation is extetided to dentine (Hansen, f982; Davidson et al., 1984; Crim, 1987). Henee, cavomarginal discolouration, post-operative sensitivity, secondar'y caries formation and bacterial penetration may result in pulpal pathosis (Douglas et al., 1989; Tjan et al., 1989). In recent years, improved marginal adaptation of indirect inlay techniques has been suggested in order to reduce the effeet of bulk polymerization of composites (Douglas et al., 1989; Sheth et al., f989b; Shortall et al., 1989). The restorations used in this technique are; (1) Composite resin inlays: made at chairside or in the Correspondence; Dr L, Karaagaelioglu, Y, Ayranci, Ho^idere Cad,, 75 (79) B/1. Ankara. Turkey. 457
458
L. Karaagaelioglu et al,
laboratory; (2) Porcelain inlays: refractory die technique, glass ceramics and Dicor inlays made in the laboratory and Cerec inlays computer designed and made at chairside (Mormann et al., 1989) These types of inlays are not only recommended for aesthetic purposes, but also give reinforcement to tooth structures (.lackson and Ferguson, 1990). For this reason fhe indications of these types of inlays are positive in heavy stress-bearing, large ar'eas (Mormann et al., 1989; Jackson & Ferguson, 1990). In luting these inlays, dual curing composite resin cements are preferred. They also ensure a complete polymerization in those areas that cannot be reached by light. The effect of polymerization shrinkage on marginal adaptation can be reduced by use of a smaller proportion of resin (Cavel et al., 1988). However, their main disadvantage is pulp toxicify r'esulting from unpolymerized monomers present in fhe resin. Because baeferial, physical and chemical irritation are primary causes of pulpal reaction, the use of a base or liner with good sealing properties is indicated, particttlarly in deep cavities (Chan & Swift, 1989), The use of glass ionomer eement (GIC) as a liner, wifh indirect inlay restorations, is used widely. The GICs first infr'oduced in 1972 are a hybrid of the silicate and polycarboxylate cements. Chemically they are formed by the r'cacfion of an ion-leachable calcium aluminosilicate glass with polyacrylic or polymaleic acid (Wilson & Kent, 1972; Kent et al., 1973), Some of fhe inherent physical and chemical properties make the GICs excellent dental restorative materials in selected clinical situations. These include fhe slow I'elease of fluoride; physicochernical bonding to enamel and dentine; bioeompatibility with pulpal tissue; a coefficient of thermal expansion that is slightly lower than that of toofh structure (Wilson & Prosser, 1984; Swiff, 1988). However there are some disadvantages such as short working time and long setting time, but manufacfur'er's are continually improving these properties. In recent years, light curing and lighfH-chemical curing glass ionomers have been developed and used clinically, Wifh these materials, modified chemistry of setting gives a pr'olonged working time and a command set as well as enhanced mechanical and physical properties. Light curing GICs are radio-opaque one component materials. Light-l-chernical curing GICs are two component materials. The powder is radio-opaque ion-leachable fluoroaluminusilicafe glass powder which is photosensitive. The liquid component is composed of light-curable polymer, water, hydroxyethylmethacrylafc and a phofoinitiator. The setting reaction consists of chelafion and then polymerization through fhe methacrylate end groups. It is suggested that, by acid-etching of GIC, bonding between composite luting agent and GIC liner can be enhanced (McLean et al., 1985), but fhe effect of etching on marginal leakage is controversial (Gar'cia-Godoy, 1988). The purpose of this investigation was to evaluate the mar'ginal seal of Class II cavities restored with Ceramco II* porcelain inlay and SR Isosit inlay'l', placed on GIC liners having different curing properties. Also, fhe effect of acid-efching of the liners on microleakage has been investigated. Materials and methods A total of 80 caries and defect-free extracted human molar teeth wer'e used in this investigation, Mesio-occlusal and disto-occlusal inlay preparations were made on all * ,lohnson and ,Iohnson, East Windsor. NJ., U,S,A, 'I' Ivoelar Schaan, Liechtenstein,
Micfoleakage of indifeet itilays
459
teeth, under the guidance of the sfudy by Shortall et al. (1989) (n:160). The inlay preparations consisted of a proximal slot preparation with no interlocking occlusal form. The cervical floor was extended approximately 0-5 mtn apical to the cetnentoenamel junction. Standard inlay preparations were made but were modified to inelude slightly rounded internal line angle to tninimize areas of stress eoticentration atid non-beveled cavosurface atigle that approached 90°, Mesiodisfal width of the cervical floor was approximately 0-75 mtn. Following cavity preparations, they were divided into 16 groups of 10 restorations (Table I). Hydrogen peroxide (3%) was utilized, as dentine pre-tr'eafment, befor'e applying tbe GIC liners to cavities. After drying the cavities, GIC liners were applied to axial dentine cavity walls and cervical walls. They were chamfered to the edge of the gingival dentinal floor (McLean et al., 1985; Katica, 1987; Shortall et al., 1989), The GIC liners used in our investigation were; (1) Light curitig Ionoseal*; (2) Light4-chemical curing LCL 8*; (3) Light-l-chetnical curing Zionomer'l'; (4) Chemical curing Ketac-Bond;]:, The light curing and light-Fchemical curing GIC liners were polymerized wifh a light curing unit Optilux 50§ for 60s. Impressions of the inlay preparations were made using a silicon impression material, Colfex fnie, If and teeth wer'e provisionally r'esfored wifh an eugenol free cement (Cavif):|:, The prepared teeth were stored in distilled water at 37°C in individual containers, until cementation of the restorations.
Table 1. Experimental groups and restorative materials Experimental groups 1 2 3 4
5 6
7 8 9 fO 11 12 13 14 15 16
* t t § f
GIC
liner Ionoseal Ionoseal LCL 8 LCL 8 Zionomer Zionomer Ketae-Bond Kctac-Bond Ionoseal Ionoseal LCL 8 LCL 8 Zionomer Zionomer Ketac-Bond Ketac-Bond
Voco Chemie, Cuxhaven. Germany Den-Mat Corp,, Santa Maria, CA, U,S,A, ESPE. GmbH, Seefeld Oberbay, Germany Demetron Rcseareh Corp,, U,S,A, Coltene AG, Altstattcn Switzerland,
Acid elch of liner -l-
+ 4-
+ + + — -1— -1—
Indirect inlay material Ceranieo 11 Ceramco 11 Ceramco H Ceramco 11 Ceranieo II Ceramco II Ceramco II Ceramco 11 SR-Isosit SR-Isosit SR-Isosit SR-lsosit SR-lsosit SR-lsosit SR-lsosit SR-lsosit
Number of restorations 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
460
L. Karaagaelioglu et al.
Following standardized laboratory procedures, Ceramco II porcelain inlays were fired and glazed on refractory models («:80), The internal surfaces of inlays were treated by means of a 1-tnin application of 30% hydrofluoric acid which effectively etches the porcelain surfaces, ther'eby creating deep micr'oporosifies. After impressions were tnade, SR-Isosit inlays were prepared on hard dental stone dies and polymerized at 120°C and 6 bar pressure for 10min, by utilizing an Ivomat pressure pot*, (/7:80). The porcelain conditioner (citric acid) supplied wifh the Ultrabond kit, was applied to the internal surfaces for a 20s period in order to clean the porcelain. The inlays were washed with wafer and thoroughly dried. Cerinate Prime'l' was then applied to the fitting surf'aees of the inlays. The internal sui'faces of resin inlays were cleaned wifb 35% phosphoric acid for 10 s application then washed and dried thoroughly. One of the purposes of our investigation was fo establish the effeet of acid-etching of GIC liners on mar'ginal leakage. For this purpose etching was used on both fhe GIC liner and enamel in mesial cavities of the feeth, but in distal cavities only fhe enamel was etched. In this two-stage application after removing of provisional cement of mesial cavities, gel etchanf was applied to the enamel margins for 60s. During the last 30s of fhe etching time, gel was placed over the surface of the GIC liner (Crim & Shay, 1987), On distal cavities, only fhe enamel surfaces were etched for 60s, After washing and drying the prepar'afions. Creation 3 in One enamel/dentine bonding agent'l' was applied fo the etched enamel and GIC liner surfaces, fhe excess was removed using compressed air. A low viscosity dual initiated hybrid composite, Ulfr'abond'l', was applied to the internal surfaces and inlays were seated individually, excess resin was removed from the cavity margins with a brush tip. The composite resin was light polymerized using three 40-s light applications. The light guide tip was placed over the occlusal sur'face of the inlay for fhe fir'sf 40 s and directed from the buccal and lingual surfaces for 40s each (Shor'fall et al., 1989). The completed restorations were checked for deficiencies and polished using burs, rubber wheels and polishing paste, Microleakage assessment The bonded specimens were stored in distilled water af 37°C, for 14 days. These were fhen sealed with two coats of nail varnish, 1 mm away frotn the restorations, and then subjected fo thermocycling. One hundred cycles were applied to the specimens, A cycle consisted of 15 s at 37°C, 15 s at 5°C, 15 s at 37°C and 15 s at 5.5°C. The teeth were retrieved and placed in a 0-5% solution of basic fuchsin dye for 24h. The nail varnish was removed and the teeth lightly pumiced to remove superfieial dye. Each tooth was sectioned longitudinally, in a mesio-distal direction through fhe centre of the restorations. The microleakage was evaluated at the following five interfaces; (1) Cervical GIC liner/dentine interface; (2) Cervical GIC liner/cornposife luting agent interface; (3) Cervical composite luting agent/restor'ation interface; (4) Occlusal r'estoration/ composite lufing agent interface; (5) Occlusal composite luting agent/enamel inter'faee.
* Ivoelar Schaan, Liechtenstein, '1' Den-Mat Corp,, Santa Maria, CA. U,S,A,
Microleakage of ittdirect itilays
461
Microleakage was scored (Figs 1 and 2) using a stereomicroscope. Wild M3Z Stereozoom Microscope*, at X40 magnification. Two examiners scored the specimens iticlependently and the scores were compared and an agreed scor'e was achieved. Mean scores were calculated for each group and statistically analyzed. Results In most specimens of all groups, sonic amount of leakage was established. Mean scores and standard errors of Interface 1 and 2 at the cervical margin of porcelain and resin inlays can be seen in Tables 2 atid 3, Talile 4 shows tnean scor'es at interface 3 and the r'esults of two interfaces af occlusal margin of por'celain and resin inlays can be seen in Table 5, After squar'e root transformation (VX4-0-5), the data of the investigation was analyzed in factorial order with analysis of variance (ANOVA), Duncan's test was used in establishing the different groups. Interface I. When porcelain and resin inlays were evaluated individually, excessive leakage was found beneath light curing Ionoseal specimens in both groups (Fig, 3). The least leakage was seen in light-l-chemical curing Zionomer and chemical curing Kefac-Bond groups. In light-l-clicmical curing LCL 8, the leakage was befween these two groups (Fig, 4), The significances according to the GIC liner materials were demonstrated in Table 2, After acid etching of GIC liners, the leakage at this interface was increased in all samples. In general, the evaluation by acid-etching of GIC liners (X 1-90; Sx:0-14; n:80)
ENAMEL
DENTINE
Composite Luting agent GIC Liner
Fig. 1. Mieroleakage scoring diagram at cervical margin lor interface l(a) (Hinoura et (tl., 1988) and interface 2 and 3 (b).
Wild Heerbrugg Ltd,, Heerbrugg. Switzerland,
462
L. Karaagaelioglu et al. (a)
(b)
ENAMEL
DENTINE GIC Liner Composite Luting agent Fig. 2. Mieroleakage seoring diagram at occlusal margin for interface 4(a) and interfaee 5(b) (Moore & Vann, 1988),
Fig. 3. Extensive microleakage at GIC liner/dentine interfaee with Ionoseal in porcelain inlay.
showed that leakage af this inferfaee was enhanced significantly compared to non acid-etched GIC liners group ¥ 1-17, Sx:O-ll; «:80) (P
Microleakage of indirect inlays placed on different kinds of glass ionomer cement linings L. KARAAGACLIOGLU, A, ZAIMOGLU am/ A,C. AKOREN Depattment of Prosthodontics, Faculty of Detttistry, University of Ankata.
Turkey
Summary The objective of this study is to compare the marginal seal of Class II eavities r'estored with indirect inlays constructed on glass ionomer cement linings having different curing pr'operties. Also the effect of acid-etching of these liners on microleakage was investigated. Mesio-occlusal and disfo-occlusal cavities in 80 extracted human molars having the cervical lloor below the cernetitoenamel junctioti were prepared (/i;160). Half of the preparations were restored with Ceramco II® porcelain and the rest with SR-Isosit® resin inlay material. Liners as light curing Ionoseal® light-l-chetnieally curing LCL 8® and Zionomer® and chernieally curing Ketac-Bond® glass ionomer cements (GICs) were used. On mesial preparations GICs were acid-etched but were not on distal preparations. All inlays were cemented with Ultrabond® composite material. After thermocycling the teeth were placed in a basic fuchsin dye solution for 24 h, then each tooth was sectioned. By using a stereornicroscope the extent of marginal leakage was scored and statistically evaluated. Mieroleakage was observed beneath all GIC linings and was more extensive between light curing GlC/dentine interface. By acid-efching of GICs the microleakage between GlC/dentine interfaee was increased significantly. Whether acid-etching was applied or not a significantly increased microleakage was recorded between chemieally curing GlC/composife interfaees. Although the marginal microleakage was witnessed in both inlays, it appeared that poreelain inlays provided a better tnarginal seal, in comparison to SR-Isosit inlays. Introduction Although, the physieal properties of recently introduced composite resins have been improved, polymerization shrinkage and the results of this continue to affect the longevity of direct posterior resin restorations (Bauer & Hanson, 1984). Polymerization shrinkage causes marginal gaps and then leakage especially, when the border of the preparation is extetided to dentine (Hansen, f982; Davidson et al., 1984; Crim, 1987). Henee, cavomarginal discolouration, post-operative sensitivity, secondar'y caries formation and bacterial penetration may result in pulpal pathosis (Douglas et al., 1989; Tjan et al., 1989). In recent years, improved marginal adaptation of indirect inlay techniques has been suggested in order to reduce the effeet of bulk polymerization of composites (Douglas et al., 1989; Sheth et al., f989b; Shortall et al., 1989). The restorations used in this technique are; (1) Composite resin inlays: made at chairside or in the Correspondence; Dr L, Karaagaelioglu, Y, Ayranci, Ho^idere Cad,, 75 (79) B/1. Ankara. Turkey. 457
458
L. Karaagaelioglu et al,
laboratory; (2) Porcelain inlays: refractory die technique, glass ceramics and Dicor inlays made in the laboratory and Cerec inlays computer designed and made at chairside (Mormann et al., 1989) These types of inlays are not only recommended for aesthetic purposes, but also give reinforcement to tooth structures (.lackson and Ferguson, 1990). For this reason fhe indications of these types of inlays are positive in heavy stress-bearing, large ar'eas (Mormann et al., 1989; Jackson & Ferguson, 1990). In luting these inlays, dual curing composite resin cements are preferred. They also ensure a complete polymerization in those areas that cannot be reached by light. The effect of polymerization shrinkage on marginal adaptation can be reduced by use of a smaller proportion of resin (Cavel et al., 1988). However, their main disadvantage is pulp toxicify r'esulting from unpolymerized monomers present in fhe resin. Because baeferial, physical and chemical irritation are primary causes of pulpal reaction, the use of a base or liner with good sealing properties is indicated, particttlarly in deep cavities (Chan & Swift, 1989), The use of glass ionomer eement (GIC) as a liner, wifh indirect inlay restorations, is used widely. The GICs first infr'oduced in 1972 are a hybrid of the silicate and polycarboxylate cements. Chemically they are formed by the r'cacfion of an ion-leachable calcium aluminosilicate glass with polyacrylic or polymaleic acid (Wilson & Kent, 1972; Kent et al., 1973), Some of fhe inherent physical and chemical properties make the GICs excellent dental restorative materials in selected clinical situations. These include fhe slow I'elease of fluoride; physicochernical bonding to enamel and dentine; bioeompatibility with pulpal tissue; a coefficient of thermal expansion that is slightly lower than that of toofh structure (Wilson & Prosser, 1984; Swiff, 1988). However there are some disadvantages such as short working time and long setting time, but manufacfur'er's are continually improving these properties. In recent years, light curing and lighfH-chemical curing glass ionomers have been developed and used clinically, Wifh these materials, modified chemistry of setting gives a pr'olonged working time and a command set as well as enhanced mechanical and physical properties. Light curing GICs are radio-opaque one component materials. Light-l-chernical curing GICs are two component materials. The powder is radio-opaque ion-leachable fluoroaluminusilicafe glass powder which is photosensitive. The liquid component is composed of light-curable polymer, water, hydroxyethylmethacrylafc and a phofoinitiator. The setting reaction consists of chelafion and then polymerization through fhe methacrylate end groups. It is suggested that, by acid-etching of GIC, bonding between composite luting agent and GIC liner can be enhanced (McLean et al., 1985), but fhe effect of etching on marginal leakage is controversial (Gar'cia-Godoy, 1988). The purpose of this investigation was to evaluate the mar'ginal seal of Class II cavities restored with Ceramco II* porcelain inlay and SR Isosit inlay'l', placed on GIC liners having different curing properties. Also, fhe effect of acid-efching of the liners on microleakage has been investigated. Materials and methods A total of 80 caries and defect-free extracted human molar teeth wer'e used in this investigation, Mesio-occlusal and disto-occlusal inlay preparations were made on all * ,lohnson and ,Iohnson, East Windsor. NJ., U,S,A, 'I' Ivoelar Schaan, Liechtenstein,
Micfoleakage of indifeet itilays
459
teeth, under the guidance of the sfudy by Shortall et al. (1989) (n:160). The inlay preparations consisted of a proximal slot preparation with no interlocking occlusal form. The cervical floor was extended approximately 0-5 mtn apical to the cetnentoenamel junction. Standard inlay preparations were made but were modified to inelude slightly rounded internal line angle to tninimize areas of stress eoticentration atid non-beveled cavosurface atigle that approached 90°, Mesiodisfal width of the cervical floor was approximately 0-75 mtn. Following cavity preparations, they were divided into 16 groups of 10 restorations (Table I). Hydrogen peroxide (3%) was utilized, as dentine pre-tr'eafment, befor'e applying tbe GIC liners to cavities. After drying the cavities, GIC liners were applied to axial dentine cavity walls and cervical walls. They were chamfered to the edge of the gingival dentinal floor (McLean et al., 1985; Katica, 1987; Shortall et al., 1989), The GIC liners used in our investigation were; (1) Light curitig Ionoseal*; (2) Light4-chemical curing LCL 8*; (3) Light-l-chetnical curing Zionomer'l'; (4) Chemical curing Ketac-Bond;]:, The light curing and light-Fchemical curing GIC liners were polymerized wifh a light curing unit Optilux 50§ for 60s. Impressions of the inlay preparations were made using a silicon impression material, Colfex fnie, If and teeth wer'e provisionally r'esfored wifh an eugenol free cement (Cavif):|:, The prepared teeth were stored in distilled water at 37°C in individual containers, until cementation of the restorations.
Table 1. Experimental groups and restorative materials Experimental groups 1 2 3 4
5 6
7 8 9 fO 11 12 13 14 15 16
* t t § f
GIC
liner Ionoseal Ionoseal LCL 8 LCL 8 Zionomer Zionomer Ketae-Bond Kctac-Bond Ionoseal Ionoseal LCL 8 LCL 8 Zionomer Zionomer Ketac-Bond Ketac-Bond
Voco Chemie, Cuxhaven. Germany Den-Mat Corp,, Santa Maria, CA, U,S,A, ESPE. GmbH, Seefeld Oberbay, Germany Demetron Rcseareh Corp,, U,S,A, Coltene AG, Altstattcn Switzerland,
Acid elch of liner -l-
+ 4-
+ + + — -1— -1—
Indirect inlay material Ceranieo 11 Ceramco 11 Ceramco H Ceramco 11 Ceranieo II Ceramco II Ceramco II Ceramco 11 SR-Isosit SR-Isosit SR-Isosit SR-lsosit SR-lsosit SR-lsosit SR-lsosit SR-lsosit
Number of restorations 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
460
L. Karaagaelioglu et al.
Following standardized laboratory procedures, Ceramco II porcelain inlays were fired and glazed on refractory models («:80), The internal surfaces of inlays were treated by means of a 1-tnin application of 30% hydrofluoric acid which effectively etches the porcelain surfaces, ther'eby creating deep micr'oporosifies. After impressions were tnade, SR-Isosit inlays were prepared on hard dental stone dies and polymerized at 120°C and 6 bar pressure for 10min, by utilizing an Ivomat pressure pot*, (/7:80). The porcelain conditioner (citric acid) supplied wifh the Ultrabond kit, was applied to the internal surfaces for a 20s period in order to clean the porcelain. The inlays were washed with wafer and thoroughly dried. Cerinate Prime'l' was then applied to the fitting surf'aees of the inlays. The internal sui'faces of resin inlays were cleaned wifb 35% phosphoric acid for 10 s application then washed and dried thoroughly. One of the purposes of our investigation was fo establish the effeet of acid-etching of GIC liners on mar'ginal leakage. For this purpose etching was used on both fhe GIC liner and enamel in mesial cavities of the feeth, but in distal cavities only fhe enamel was etched. In this two-stage application after removing of provisional cement of mesial cavities, gel etchanf was applied to the enamel margins for 60s. During the last 30s of fhe etching time, gel was placed over the surface of the GIC liner (Crim & Shay, 1987), On distal cavities, only fhe enamel surfaces were etched for 60s, After washing and drying the prepar'afions. Creation 3 in One enamel/dentine bonding agent'l' was applied fo the etched enamel and GIC liner surfaces, fhe excess was removed using compressed air. A low viscosity dual initiated hybrid composite, Ulfr'abond'l', was applied to the internal surfaces and inlays were seated individually, excess resin was removed from the cavity margins with a brush tip. The composite resin was light polymerized using three 40-s light applications. The light guide tip was placed over the occlusal sur'face of the inlay for fhe fir'sf 40 s and directed from the buccal and lingual surfaces for 40s each (Shor'fall et al., 1989). The completed restorations were checked for deficiencies and polished using burs, rubber wheels and polishing paste, Microleakage assessment The bonded specimens were stored in distilled water af 37°C, for 14 days. These were fhen sealed with two coats of nail varnish, 1 mm away frotn the restorations, and then subjected fo thermocycling. One hundred cycles were applied to the specimens, A cycle consisted of 15 s at 37°C, 15 s at 5°C, 15 s at 37°C and 15 s at 5.5°C. The teeth were retrieved and placed in a 0-5% solution of basic fuchsin dye for 24h. The nail varnish was removed and the teeth lightly pumiced to remove superfieial dye. Each tooth was sectioned longitudinally, in a mesio-distal direction through fhe centre of the restorations. The microleakage was evaluated at the following five interfaces; (1) Cervical GIC liner/dentine interface; (2) Cervical GIC liner/cornposife luting agent interface; (3) Cervical composite luting agent/restor'ation interface; (4) Occlusal r'estoration/ composite lufing agent interface; (5) Occlusal composite luting agent/enamel inter'faee.
* Ivoelar Schaan, Liechtenstein, '1' Den-Mat Corp,, Santa Maria, CA. U,S,A,
Microleakage of ittdirect itilays
461
Microleakage was scored (Figs 1 and 2) using a stereomicroscope. Wild M3Z Stereozoom Microscope*, at X40 magnification. Two examiners scored the specimens iticlependently and the scores were compared and an agreed scor'e was achieved. Mean scores were calculated for each group and statistically analyzed. Results In most specimens of all groups, sonic amount of leakage was established. Mean scores and standard errors of Interface 1 and 2 at the cervical margin of porcelain and resin inlays can be seen in Tables 2 atid 3, Talile 4 shows tnean scor'es at interface 3 and the r'esults of two interfaces af occlusal margin of por'celain and resin inlays can be seen in Table 5, After squar'e root transformation (VX4-0-5), the data of the investigation was analyzed in factorial order with analysis of variance (ANOVA), Duncan's test was used in establishing the different groups. Interface I. When porcelain and resin inlays were evaluated individually, excessive leakage was found beneath light curing Ionoseal specimens in both groups (Fig, 3). The least leakage was seen in light-l-chemical curing Zionomer and chemical curing Kefac-Bond groups. In light-l-clicmical curing LCL 8, the leakage was befween these two groups (Fig, 4), The significances according to the GIC liner materials were demonstrated in Table 2, After acid etching of GIC liners, the leakage at this interface was increased in all samples. In general, the evaluation by acid-etching of GIC liners (X 1-90; Sx:0-14; n:80)
ENAMEL
DENTINE
Composite Luting agent GIC Liner
Fig. 1. Mieroleakage scoring diagram at cervical margin lor interface l(a) (Hinoura et (tl., 1988) and interface 2 and 3 (b).
Wild Heerbrugg Ltd,, Heerbrugg. Switzerland,
462
L. Karaagaelioglu et al. (a)
(b)
ENAMEL
DENTINE GIC Liner Composite Luting agent Fig. 2. Mieroleakage seoring diagram at occlusal margin for interface 4(a) and interfaee 5(b) (Moore & Vann, 1988),
Fig. 3. Extensive microleakage at GIC liner/dentine interfaee with Ionoseal in porcelain inlay.
showed that leakage af this inferfaee was enhanced significantly compared to non acid-etched GIC liners group ¥ 1-17, Sx:O-ll; «:80) (P
