Microtensile bond strength of repaired indirect resin composite

PURPOSE: The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded to a conventional direct resin composite. MATERIALS AND METHODS: Indirect resin composite blocks of Ceramage and SR Nexco were prepared in a plastic mold having a dimension of 10 × 10 × 4 mm. These composite blocks were divided into three groups according to their surface treatments: Group1: Sandblast (SB); Group2: Sandblast and ultrasonically clean (SB+UL); Group3: Sandblast plus silane (SB+SI). After bonding with direct resin composite, indirect-direct resin composite blocks were kept in distilled water for 24 hours at 37℃ and cut into microbars with the dimension of 1 × 1 × 8 mm. Microbar specimens (n = 40 per group) were loaded using a universal testing machine. Failure modes and compositions were evaluated by SEM. The statistical analyses of MTBS were performed by two-way ANOVA and Dunnett's test at α = .05. RESULTS: Surface treatments and brands had effects on the MTBS without an interaction between these two factors. For SR Nexco, the MTBSs of SB and SB+SI group were significantly higher than that of SB+UL. For Ceramage, the MTBSs of SB and SB+SI were significantly higher than that of SB+UL. The mean MTBS of the Ceramage specimens was significantly higher than that of SR Nexco for all surface treatments. CONCLUSION: Sandblasting with or without silane application could improve the bond strengths of repaired indirect resin composites to a conventional direct resin composite.

The evaluation of color and color difference according to the layering placement of Incisal shade composites on the body composites of the indirect resin restoration / 대한치과보존학회지

OBJECTIVES: The aim of this study was to evaluate the surface color of indirect resin restoration according to the layering placement of different shade of incisal composite. MATERIALS AND METHODS: In this study, CIE L*a*b* value of 16 Body composite of Tescera ATL (Bisco, Schaumburg IL,USA) was measured by spectrophotometer (NF999, Nippon Denshuku, Japan), and compared to CIE L*a*b* value of Vitapan shade guide. Nine shade Incisal composite of Tescera ATL were build-up to 1 mm thickness on Body composites inlay block, and CIE L*a*b* value was measured. Incisal composite was ground to 0.5 mm thickness and CIE L*a*b* value was re-measured. Color difference between Body composite and Incisal composites layered on Body composite was calculated as a function of thickness. RESULTS: Color difference between corresponding shade of Tescera Body composite and Vitapan shade guide was from 6.88 to 12.80. L* and b*value was decreased as layering thickness of Incisal composite on Body composite was increased. But, a* value did not show specific change tendency. CONCLUSIONS: Surface color difference between Body composites and Incisal composites layered on Body composite was increased as the layering thickness of Incisal composite increased (p < 0.05).

Influencia del envejecimiento, la marca y la ubicación de las fibras de refuerzos en la resistencia felxural de la resina compuesta Gradia® / Age influence, brand and location of reinforcement fibers in the resistance of the composite resin felxural Gradia®

La incorporación de fibras de refuerzo a resinas compuestas se ha convertido en una alternativa de tratamiento protésico altamente conservador. De esta investigación fue evaluar la resistencia flexural (RF) de una resina compuesta indirecta reforzada con tres diferentes marcas comerciales de fibras de vidrio, variando su ubicación y sometidas a envejecido físico ó químico. Se fabricaron 98 especímenes de resina compuesta Gradia™ (GC-America Inc.) de 22 mm x 2 mm x 3 mm; a 14 muestras no se les colocó fibras (SF), se almacenaron en agua destilada por 60 días, luego se subdividieron en dos grupos de 7 muestras,G1 - SFA y G2 - SFT el cual se sometió a termociclado (3000 ciclos de 5°/55°C en intervalos de 1 min); las otras 84 muestras se reforzaron fibras unidireccionales: 42 muestras para ser almacenadas en agua por 60 días (CFA), divididas en dos sub-grupos de 21, en relación a la ubicación de la fibra en la zona de compresión (CFAC) ó tracción (CFAT); finalmente en tres grupos de 7, dependiendo de la marca; Fibrex-Lab® (Angelus) los grupos G3 - CFACFLab y G6 - CFATFLab, FibreKor® (Jeneric/Penton) los grupos G4 - CFACFKor y G7 - CFATFKor y Vectris® (Ivoclar/Vivadent) los grupos G5 - CFACVectris y G8 - CFATVectris. Las 42 restantes después del almacenamiento en agua se sometieron al termociclado , se dividieron en dos subgrupos de 21, en relación a la ubicación de la fibra en la zona de compresión (CFTC) ó de tracción (CFTT); finalmente se dividió en tres grupos de 7, entonces Fibrex-Lab® conformó los grupos G9 - CFTCFLab y G12 - CFTTFLab, FibreKor® los grupos G10 - CFTCFKor y G13 - CFTTFKor y Vectris® los grupos G11 - CFTCVectris y G14 - CFTTVectris. Las muestras fueron sometidas a la prueba de flexión de tres puntos hasta su fractura, en maquina de pruebas universales (Shimadzu AGS-J) a una velocidad de 1mm/min. Los datos fueron recolectados, tabulados en hoja de cálculo y luego analizados con un estadístico de t de student....

The incorporation of reinforce fibers to composite has turned into an alternative of high conservative prosthetic treatment. The aim of this study was to evaluate the flexure strength (RF) of a indirect reinforce composite using three fiber glass commercial brands, varying the location and submitted to physical o chemical aging. 98 specimen were made of 22 mm x 2 mm x 3 mm Gradia™ resin compound (GC-America Inc.); 14 samples were not reinforce with fiber glass (SF), They were store in distilled water for 60 days then divided in 2 groups of 7 samples, G1 - SFA and G2 - SFT was thermocycled (3000 cycles of 5 °/55°C in intervals of 1 min); the other 82 samples were reinforce with unidirectional fibers: 42 to be stored in distilled water for 60 days (CFA), divided in 2 subgroups of 21, in relation with the localization of the fiber on the compression zone (CFAC) or traction (CFAT); Finally divided in 3 groups of 7, depending on the brand; Fibrex-Lab® (Angelus) the groups G3 - CFACFLab and G6 - CFATFLab, FibreKor® (Jeneric/Penton) the groups G4 - CFACFKor and G7 - CFATFKor and Vectris® (Ivoclar/Vivadent) the groups G5 - CFACVectris and G8 - CFATVectris. The remaining 42 samples after storage in water were submitted to thermocycling, divided in 2 subgroups of 21, in relation with the localization of the fiber on the compression zone (CFTC) or traction (CFTT); Finally divided in 3 groups of 7 then G9 was conformed Fibrex-Lab® CFTCFLab and G12 - CFTTFLab, FibreKor® the groups G10 - CFTCFKor and G13 - CFTTFKor and Vectris® the groups G11 - CFTCVectris and G14 - CFTTVectris. The samples were submitted to the three points flexion test until fracture, in a universal testing machine (Shimadzu AGS-J) to a speed of 1mm/min. The information was gathered, tabulated in spreadsheet and then analyzed with a statistician t of student to determine differences between the groups without fibers and 3 factors ANOVA on the reinforced groups for the varying location...

The effect of various bonding systems on the microtensile bond strength of immediate and delayed dentin sealing / 대한치과보존학회지

The purpose of this study was to compare the effect of various dentin bonding systems on microtensile bond strength of immediate dentin sealing (IDS) and delayed dentin sealing (DDS). Eighteen extracted permanent molars were used in this study. The teeth for DDS group were restored with a provisional restorations, and immersed in saline solution for 1 week, and divided into 3 subgroups according to various dentin bonding adhesives; SB subgroup (3 step total-etch adhesive), SE subgroup (2 step self-etch adhesive), XE subgroup (1 step self-etch adhesive). In IDS group, the teeth were divided into 3 subgroups, and applied with bonding adhesives as in DDS group. The teeth were restored with provisional restorations, and immersed in saline solution for 1 week. Indirect composite disc was cemented with resin cement, and all specimens were subjected to microtensile bond strength. The data were statistically analyzed with one-way ANOVA and Student t-test. The results were as follows: 1. The IDS group showed significantly higher microTBS than DDS group in 3 step total-etch and 2 step self-etch adhesive (p < 0.05). 2. In IDS and DDS group, 3 step total-etch adhesive showed the highest microTBS value, followed by 2 step self-etch, and 1 step self-etch adhesive. In IDS group, the microTBS value for 1 step self-etch adhesive was significantly different from those of the other subgroups (p < 0.05), and in DDS group, there were statistical differences in all subgroup (p < 0.05). 3. Failure modes of tested dentin bonding adhesives were mostly mixed failure and only 1 step self-etch adhesive showed adhesive failure.

Comparison of mechanical properties in 4 indirect composite resin / 대한치과보철학회지

STATEMENT OF PROBLEM: The esthetic component of dental care has become increasingly more important, while new tooth-colored materials are continually marketed. Various new indirect composite materials have been developed with required advantages. The most recent development in the indirect composites has been the introduction of the second-generation laboratory composite or poly-glass materials. They are processed by different laboratory techniques based on combinations of heat, pressure, vacuum and light polymerization. Although, second generation products became available in 1995, their characteristics and clinical performance have not been adequately investigated. PURPOSE: The aim of this study was to measure the mechanical properties of the second generation indirect resin system and compare these with an existing universal direct composite resin. MATERIAL AND METHOD: In this study four indirect composite material (Adoro LC, BelleGlass HP, Tescera, Synfony) were tested for flexural strength, wear resistance, hardness and their degree of conversion against Z250, a light cure direct composite. RESULTS: Within the limitations of this study, the following conclusions were drawn: 1. From the abrasion wear result, Adoro showed the least volume loss while Synfony showed the greatest volume loss. Z250 and BelleGlass HP didn't show significant difference (p>0.05), but they showed significant difference with other groups (p0.05). While Synfony showed the greatest volume loss that it showed significant difference with other groups (p>0.05). 2. Mean values of flexural strength by means of three point bending test was in the order of Z250, Adoro, Belleglass HP, Tescera and Synfony. Mean elastic modulus was in the order of Z250, BelleGlass HP, Tescera, Adoro and Synfony. 3. The result of Vicker's microhardness value showed that significantly higher value in Z250 (p<0.05), and is in the order of BelleGlass HP, Tescera, Adoro and Synfony. 4. The degree of conversion measured by FT-IR showed significantly higher value in BelleGlass HP (p<0.05), and is in the order of Adoro, Synfony, Tescera and Z250. CONCLUSION: Significant differences were found in the flexural strength, wear resistance, hardness and their degree of conversion.

Compatibility of self-etching dentin adhesives with resin luting cements / 대한치과보존학회지

This study was performed to investigate the compatibility between 4 dentin adhesives and 4 resin luting cements. Dentin adhesives used in this study were All-Bond 2 (Bisco Inc., Schaumbrug, IL, USA), Clearfil SE-Bond (Kuraray Medical Inc, Osaka, Japan), Prompt L-Pop (3M Dental Products, St. Paul, MN, USA), One-Up Bond F (Tokuyama corp., Tokyo, Japan). Resin luting cements used in this study were Choice (Bisco Inc., Schaumbrug, IL, USA), Panavia F (Kuraray Medical Inc, Osaka, Japan), RelyX ARC (3M Dental Products, St. Paul, MN, USA), Bistite II DC (Tokuyama corp., Tokyo, Japan). Combination of each dentin adhesive and corresponding resin cement was made to 16 experimental groups. Flat dentin surfaces was created on mid-coronal dentin of extracted mandibular third molars, then dentin surface was polished with 320-grit silicon carbide abrasive papers. Indirect resin composite block (Tescera, Bisco) was fabricated. Its surface for bonding to tooth was polished with silicon carbide abrasive papers. Each dentin adhesive was treated on tooth surface and resin composite overlay were luted with each resin cement. Each bonded specimen was poured in epoxy resin and sectioned occluso-gingivally into 1.0 mm thick slab, then further sectioned into 1.0 x 1.0 mm2 composite-dentin beams. Microtensile bond strength was tested at a crosshead speed of 1.0 mm/min. The data were analysed by one-way ANOVA and Duncan's multiple comparison tests. The results of this study were as follows; 2-step self-etching dentin adhesive which has additional bonding resin is more compatible than 1-step self-etching dentin adhesive.

Influence of cavity size and restoration methods on the cusp deflection in composite restoration / 대한치과보존학회지

The aim of this study was to measure the cusp deflection during composite restoration for MOD cavity in premolar and to examine the influence of cavity dimension, C-factor and restoration method on the cusp deflection. Thirty extracted maxillary premolar were prepared to four different sizes of MOD cavity and divided into six groups. The width and depth of the cavity were as follows. Group 1; 1.5 x 1 mm, Group 2; 1.5 x 2 mm, Group 3; 3 x 1 mm, and Group 4-6; 3 x 2 mm respectively. Group 1-4 were restored using bulk filling method with Z-250 composite. However, Group 5 was restored incrementally, and Group 6 was restored with an indirect resin inlay. The cusp deflection was recorded at the buccal and lingual cusp tips using LVDT probe for 10,000 seconds. The measured cusp deflections were compared between groups, and the relationship between the cube of the length of cavity wall/the cube of the thickness of cavity wall (L3 / T3), C-factor and cusp deflection or %flexure (100 x cuspal deflection / cavity width) was analyzed. The cusp deflection of Group 1-4 were 12.1 microm, 17.2 microm, 16.2 microm and 26.4 microm respectively. The C-factor was related to the %flexure rather than the cusp deflection. There was a strong positive correlationship between the L3 / T3 and the cusp deflection. The cusp deflection of Group 5 and 6 were 17.4 microm and 17.9 microm respectively, which are much lower value than that of Group 4.

Shear bond strength of repaired composite resin restorations / 대한치과보존학회지

This study was performed to evaluate the interfacial shear bond strength of base (direct and indirect) and repair composites with aging and surface treatment methods. Direct composite resin specimens (Charisma(R), Heraeus Kulzer, Germany) were aged for 5 min, 1 hour, 24 hours, and 1 week in 37degrees C distilled water before surface treatment, and then divided into five groups: Group 1, grinding; Group 2, grinding and application of bonding agent; Group 3, grinding, etching with 37% phosphoric acid for 30sec, and application of bonding agent; Group 4, grinding, etching with 37% phosphoric acid for 30sec, silane treatment, and application of bonding agent; Group 5, grinding, etching with 4% hydrofluoric acid for 30sec, silane treatment, and application of bonding agent. Indirect composite resin specimens (Artglass(R), Heraeus Kulzer, Germany) were aged for 1 week in 37degrees C distilled water and divided into seven groups: Group 1 - Group 5, equal to Charisma specimens; Group 6, grinding, etching with 37% phosphoric acid for 60sec, silane treatment, and application of bonding agent; Group7, grinding, etching with 4% hydrofluoric acid for 60 sec, silane treatment, and application of bonding agent. The repair material(Charisma(R)) was then added on the center of the surface (5 mm in diameter, 5 mm in height). The shear bond strength was tested and the data was analyzed using one-way ANOVA and the Student-Newman-Keuls test. The following conclusions were drawn. 1. The shear bond strength of Charisma(R) specimens aged for 1 hour was significantly higher in Group 2 and Group 5 than in Group 1 (p<0.05), and that of Charisma(R) specimens aged for 1 week was significantly higher in Group 3 and Group 5 than in Group 1 (p<0.05). No significant difference was found in the bond strength of specimens aged for 5 min and 24 hours. 2. In Group 2 of the Charisma(R) specimens, there was significant difference between the bond strength of 24 hours and that of 1 week (p<0.05). 3. In Group 4 of the Charisma(R) specimens, the shear bond strength of specimens aged for 24 hours was significantly higher than the others(p<0.05). 4. There was no significant difference between the shear bond strength of the Artglass(R) specimens. 5. Most of the Charisma(R) specimens showed cohesive fractures. Artglass(R) specimens that were etched with acid (phosphoric or hydrofluoric) for 30 sec showed more cohesive fractures.