The international journal of esthetic dentistry, 2016
To assess the influence of conventional glass ionomer cement (GIC) vs resin-modified GIC (RMGIC) ... more To assess the influence of conventional glass ionomer cement (GIC) vs resin-modified GIC (RMGIC) as a base material for novel, super-closed sandwich restorations (SCSR) and its effect on shrinkage-induced crack propensity and in vitro accelerated fatigue resistance. A standardized MOD slottype tooth preparation was applied to 30 extracted maxillary molars (5 mm depth/5 mm buccolingual width). A modified sandwich restoration was used, in which the enamel/dentin bonding agent was applied first (Optibond FL, Kerr), followed by a Ketac Molar (3M ESPE)(group KM, n = 15) or Fuji II LC (GC) (group FJ, n = 15) base, leaving 2 mm for composite resin material (Miris 2, Coltène-Whaledent). Shrinkageinduced enamel cracks were tracked with photography and transillumination. Samples were loaded until fracture or to a maximum of 185,000 cycles under isometric chewing (5 H z), starting with a load of 200 N (5,000 X), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,...
Since the early reports on home bleaching under clinician supervision by means of nocturnal plate... more Since the early reports on home bleaching under clinician supervision by means of nocturnal plates bearing a peroxide-based whitening agent, the benefits of this tech-nique were quickly recognized by the profession, and it became a very popular cosmetic procedure widely accepted by the public. Although this procedure has become widespread, 2 efficient 6 and reliable, enabling predictable results, the use of these bleaching agents can provoke morphologic changes in enamel, dentin, and cement, 7 such as changes to their chemical composition, 3 to the surface microhardness of enamel and dentin, 1,4,8-10 and to bonding with resin systems.
Quintessence international (Berlin, Germany : 1985), 2005
This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day an... more This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day and 7 hours/day) using 10% carbamide peroxide (Nite White Excel 2Z) on the surface microhardness of dentin over a 21-day period. Nine blocks of dentin derived from the teeth of subjects, each with at least two thirds molar in need of extraction, were obtained from the cervical region and submitted to surface-hardness analysis (Shimadsu HMV/2000), fixed to an intraoral palate device fabricated for each subject, and positioned (3 left side, 3 right side, 3 center) according to experimental group. During the bleaching period, casts bearing the whitening agent were applied to the blocks for 7, 1, and 0 hours, respectively (7 left side, 3 right side, 0 center). After the treatment period, the specimens were once again submitted to microhardness analysis, using the same equipment as before, and then analysis of variance and the Scheffé test were applied to the mean differences between the initia...
The current study investigated the effects of different polishing systems on the surface roughnes... more The current study investigated the effects of different polishing systems on the surface roughness and microhardness of a silorane-based resin composite. Forty disks were fabricated (ø = 12 mm, h = 2.5 mm) of Filtek P90 (3 M ESPE, USA). The specimens were divided into four groups (n = 10), according to the polishing system: G1 -Mylar strip (control); G2 -Felt-disc + diamond paste, G3 -Sandpaper discs; G4 -Silicone tips. The specimens were stored in distilled water at 37°C for 24 h. The external surface roughness was determined through measuring the R a of the specimens. The Vickers microhardness was measured using a microhardness tester. The values of surface roughness and microhardness of each specimen were statistically analyzed using one-way ANOVA, Games-Howell and Ryan-Einot-Gabriel-Welsch (REGW-Q), and setting the statistical significance at p ≤ 0.05. It was observed that G2 (0.42 μm) and G4 (0.43 μm) showed statistically significant differences when compared to groups G1 (0.25 μm) and G3 (0.19 μm) (p <0.05). There was no statistical difference between groups regarding microhardness (p > 0.05). The polishing systems altered the surface roughness of a silorane-based resin composite, but did not influence the microhardness values.
Statement of Problem. After the occlusal adjustment of a ceramic restoration, polishing is necess... more Statement of Problem. After the occlusal adjustment of a ceramic restoration, polishing is necessary to promote surface smoothness and increase the ceramic flexural strength. However, the internal adjustment procedure may affect ceramic flexural strength.
Finishing of composites may adversely influence the sealing ability of direct adhesive restoratio... more Finishing of composites may adversely influence the sealing ability of direct adhesive restorations. This study was conducted to determine whether finishing time and techniques under wet or dry conditions affect the microleakage of 2 types of class V composite restorations. Eighty class V preparations were made in the buccal surfaces of noncarious molars with the occlusal margins ending in enamel and the gingival margins in dentin. Dental adhesive (Single Bond) was applied according to the manufacturer&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s instructions. Half of the preparations were restored with a microfilled composite (Silux Plus) and the other half with a hybrid composite (Filtek Z250). Within each major composite group (n = 40), 4 subgroups (n = 10) were established based on finishing technique (diamond finishing burs or aluminum oxide discs) and finishing time (immediate or delayed by 24 hours). The specimens were stored for 24 hours in 37 degrees C water, thermocycled for 250 cycles between 5 degrees C and 55 degrees C, immersed in 2% methylene blue solution for another 24 hours, and sectioned longitudinally. For both enamel and dentin margins, dye solution penetration at the tooth/composite interface was scored from 0 to 4 under stereoscopy at original magnification x 20. Data were analyzed with the Kruskal-Wallis test (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). Significantly lower leakage scores were recorded for teeth restored with microfilled composite and finished under wet conditions after 24 hours (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.01). No significant differences were found among the hybrid composite groups. For microfilled composite restorations on dentin margins, delayed wet finishing with diamond burs resulted in significantly lower microleakage scores than all other finishing protocols. Hybrid composite restorations had equivalent levels of microleakage regardless of the finishing method.
Journal of Esthetic and Restorative Dentistry, 2001
The functional and esthetic restoration of severely compromised anterior teeth is a challenge to ... more The functional and esthetic restoration of severely compromised anterior teeth is a challenge to clinicians in their daily practice. The duplication of the optical characteristics of an intact tooth, including shade, translucency, and fluorescence, is often made difficult by the use of metal infrastructures, such as post-and-cores and copings. The development of reinforced ceramics and nonmetallic post systems made possible the generation of metal-free ceramic restorations in severely compromised anterior and posterior teeth. This article discusses one available technique for the generation of a single all-ceramic restoration involving the use of a zirconia-or leucite-reinforced post-and-core system and of an all-ceramic crown system. A representative clinical case is presented illustrating the potential of the technique. 0 2 0 0 1 BC Decker Inc
Thin, bonded, posterior occlusal veneers constitute a conservative alternative to traditional com... more Thin, bonded, posterior occlusal veneers constitute a conservative alternative to traditional complete coverage crowns. Information regarding selection of the appropriate material and its influence on fatigue resistance, which may affect the longevity of the restoration, is missing.
The purpose of the study was to evaluate the effect of autoclaving one-step polishing systems on ... more The purpose of the study was to evaluate the effect of autoclaving one-step polishing systems on the surface roughness of a nanoparticle resin composite. Sixty disk-shaped specimens were fabricated (ø 12 mm and 2.5 mm height) with Tetric N-Ceram (IvoclarVivadent). Thirty discs were polished with brushes (Astrobrush, IvoclarVivadent)and the other 30 discs with rubber tips (Optrapol, Ivoclar Vivadent). The specimens were divided into 6 groups (n = 10), according to the association between polishing system and number of autoclave cycles: G1, Astrobrush used for first time and without autoclave (control); G2, Astrobrush used after the 10th autoclave cycle; G3, Astrobrush used after the 20th autoclave cycle; G4, Optrapol used for first time and without autoclave (control); G5, Optrapol used after the 10th autoclave cycle; G6, Optrapol used after the 20th autoclave cycle. The surface roughness (R a ) of each specimen and the data was used for analysis of variance (ANOVA). There was no significantly statistical difference between groups for both of the one-step polishing systems (p > 0.05). The Astrobrush system presented R a values statistically lower than Optrapol system (p < 0.05). Twenty cycles of autoclaving, did not affect the surface roughness produced by polishing systems on the resin composite evaluated.
To assess the influence of material/technique selection (direct vs. CAD/CAM inlays) for large MOD... more To assess the influence of material/technique selection (direct vs. CAD/CAM inlays) for large MOD composite adhesive restorations and its effect on the crack propensity and in vitro accelerated fatigue resistance. A standardized MOD slot-type tooth preparation was applied to 32 extracted maxillary molars (5mm depth and 5mm bucco-palatal width) including immediately sealed dentin for the inlay group. Fifteen teeth were restored with direct composite resin restoration (Miris2) and 17 teeth received milled inlays using Paradigm MZ100 block in the CEREC machine. All inlays were adhesively luted with a light curing composite resin (Filtek Z100). Enamel shrinkage-induced cracks were tracked with photography and transillumination. Cyclic isometric chewing (5 Hz) was simulated, starting with a load of 200 N (5000 cycles), followed by stages of 400, 600, 800, 1000, 1200 and 1400 N at a maximum of 30,000 cycles each. Samples were loaded until fracture or to a maximum of 185,000 cycles. Teeth restored with the direct technique fractured at an average load of 1213 N and two of them withstood all loading cycles (survival=13%); with inlays, the survival rate was 100%. Most failures with Miris2 occurred above the CEJ and were re-restorable (67%), but generated more shrinkage-induced cracks (47% of the specimen vs. 7% for inlays). CAD/CAM MZ100 inlays increased the accelerated fatigue resistance and decreased the crack propensity of large MOD restorations when compared to direct restorations. While both restorative techniques yielded excellent fatigue results at physiological masticatory loads, CAD/CAM inlays seem more indicated for high-load patients.
Journal of Esthetic and Restorative Dentistry, 2012
Background: The translucency of enamel shade is a crucial property that affects the color of a la... more Background: The translucency of enamel shade is a crucial property that affects the color of a layered restoration.
The international journal of esthetic dentistry, 2016
To assess the influence of conventional glass ionomer cement (GIC) vs resin-modified GIC (RMGIC) ... more To assess the influence of conventional glass ionomer cement (GIC) vs resin-modified GIC (RMGIC) as a base material for novel, super-closed sandwich restorations (SCSR) and its effect on shrinkage-induced crack propensity and in vitro accelerated fatigue resistance. A standardized MOD slottype tooth preparation was applied to 30 extracted maxillary molars (5 mm depth/5 mm buccolingual width). A modified sandwich restoration was used, in which the enamel/dentin bonding agent was applied first (Optibond FL, Kerr), followed by a Ketac Molar (3M ESPE)(group KM, n = 15) or Fuji II LC (GC) (group FJ, n = 15) base, leaving 2 mm for composite resin material (Miris 2, Coltène-Whaledent). Shrinkageinduced enamel cracks were tracked with photography and transillumination. Samples were loaded until fracture or to a maximum of 185,000 cycles under isometric chewing (5 H z), starting with a load of 200 N (5,000 X), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,...
Since the early reports on home bleaching under clinician supervision by means of nocturnal plate... more Since the early reports on home bleaching under clinician supervision by means of nocturnal plates bearing a peroxide-based whitening agent, the benefits of this tech-nique were quickly recognized by the profession, and it became a very popular cosmetic procedure widely accepted by the public. Although this procedure has become widespread, 2 efficient 6 and reliable, enabling predictable results, the use of these bleaching agents can provoke morphologic changes in enamel, dentin, and cement, 7 such as changes to their chemical composition, 3 to the surface microhardness of enamel and dentin, 1,4,8-10 and to bonding with resin systems.
Quintessence international (Berlin, Germany : 1985), 2005
This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day an... more This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day and 7 hours/day) using 10% carbamide peroxide (Nite White Excel 2Z) on the surface microhardness of dentin over a 21-day period. Nine blocks of dentin derived from the teeth of subjects, each with at least two thirds molar in need of extraction, were obtained from the cervical region and submitted to surface-hardness analysis (Shimadsu HMV/2000), fixed to an intraoral palate device fabricated for each subject, and positioned (3 left side, 3 right side, 3 center) according to experimental group. During the bleaching period, casts bearing the whitening agent were applied to the blocks for 7, 1, and 0 hours, respectively (7 left side, 3 right side, 0 center). After the treatment period, the specimens were once again submitted to microhardness analysis, using the same equipment as before, and then analysis of variance and the Scheffé test were applied to the mean differences between the initia...
The current study investigated the effects of different polishing systems on the surface roughnes... more The current study investigated the effects of different polishing systems on the surface roughness and microhardness of a silorane-based resin composite. Forty disks were fabricated (ø = 12 mm, h = 2.5 mm) of Filtek P90 (3 M ESPE, USA). The specimens were divided into four groups (n = 10), according to the polishing system: G1 -Mylar strip (control); G2 -Felt-disc + diamond paste, G3 -Sandpaper discs; G4 -Silicone tips. The specimens were stored in distilled water at 37°C for 24 h. The external surface roughness was determined through measuring the R a of the specimens. The Vickers microhardness was measured using a microhardness tester. The values of surface roughness and microhardness of each specimen were statistically analyzed using one-way ANOVA, Games-Howell and Ryan-Einot-Gabriel-Welsch (REGW-Q), and setting the statistical significance at p ≤ 0.05. It was observed that G2 (0.42 μm) and G4 (0.43 μm) showed statistically significant differences when compared to groups G1 (0.25 μm) and G3 (0.19 μm) (p <0.05). There was no statistical difference between groups regarding microhardness (p > 0.05). The polishing systems altered the surface roughness of a silorane-based resin composite, but did not influence the microhardness values.
Statement of Problem. After the occlusal adjustment of a ceramic restoration, polishing is necess... more Statement of Problem. After the occlusal adjustment of a ceramic restoration, polishing is necessary to promote surface smoothness and increase the ceramic flexural strength. However, the internal adjustment procedure may affect ceramic flexural strength.
Finishing of composites may adversely influence the sealing ability of direct adhesive restoratio... more Finishing of composites may adversely influence the sealing ability of direct adhesive restorations. This study was conducted to determine whether finishing time and techniques under wet or dry conditions affect the microleakage of 2 types of class V composite restorations. Eighty class V preparations were made in the buccal surfaces of noncarious molars with the occlusal margins ending in enamel and the gingival margins in dentin. Dental adhesive (Single Bond) was applied according to the manufacturer&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s instructions. Half of the preparations were restored with a microfilled composite (Silux Plus) and the other half with a hybrid composite (Filtek Z250). Within each major composite group (n = 40), 4 subgroups (n = 10) were established based on finishing technique (diamond finishing burs or aluminum oxide discs) and finishing time (immediate or delayed by 24 hours). The specimens were stored for 24 hours in 37 degrees C water, thermocycled for 250 cycles between 5 degrees C and 55 degrees C, immersed in 2% methylene blue solution for another 24 hours, and sectioned longitudinally. For both enamel and dentin margins, dye solution penetration at the tooth/composite interface was scored from 0 to 4 under stereoscopy at original magnification x 20. Data were analyzed with the Kruskal-Wallis test (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). Significantly lower leakage scores were recorded for teeth restored with microfilled composite and finished under wet conditions after 24 hours (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.01). No significant differences were found among the hybrid composite groups. For microfilled composite restorations on dentin margins, delayed wet finishing with diamond burs resulted in significantly lower microleakage scores than all other finishing protocols. Hybrid composite restorations had equivalent levels of microleakage regardless of the finishing method.
Journal of Esthetic and Restorative Dentistry, 2001
The functional and esthetic restoration of severely compromised anterior teeth is a challenge to ... more The functional and esthetic restoration of severely compromised anterior teeth is a challenge to clinicians in their daily practice. The duplication of the optical characteristics of an intact tooth, including shade, translucency, and fluorescence, is often made difficult by the use of metal infrastructures, such as post-and-cores and copings. The development of reinforced ceramics and nonmetallic post systems made possible the generation of metal-free ceramic restorations in severely compromised anterior and posterior teeth. This article discusses one available technique for the generation of a single all-ceramic restoration involving the use of a zirconia-or leucite-reinforced post-and-core system and of an all-ceramic crown system. A representative clinical case is presented illustrating the potential of the technique. 0 2 0 0 1 BC Decker Inc
Thin, bonded, posterior occlusal veneers constitute a conservative alternative to traditional com... more Thin, bonded, posterior occlusal veneers constitute a conservative alternative to traditional complete coverage crowns. Information regarding selection of the appropriate material and its influence on fatigue resistance, which may affect the longevity of the restoration, is missing.
The purpose of the study was to evaluate the effect of autoclaving one-step polishing systems on ... more The purpose of the study was to evaluate the effect of autoclaving one-step polishing systems on the surface roughness of a nanoparticle resin composite. Sixty disk-shaped specimens were fabricated (ø 12 mm and 2.5 mm height) with Tetric N-Ceram (IvoclarVivadent). Thirty discs were polished with brushes (Astrobrush, IvoclarVivadent)and the other 30 discs with rubber tips (Optrapol, Ivoclar Vivadent). The specimens were divided into 6 groups (n = 10), according to the association between polishing system and number of autoclave cycles: G1, Astrobrush used for first time and without autoclave (control); G2, Astrobrush used after the 10th autoclave cycle; G3, Astrobrush used after the 20th autoclave cycle; G4, Optrapol used for first time and without autoclave (control); G5, Optrapol used after the 10th autoclave cycle; G6, Optrapol used after the 20th autoclave cycle. The surface roughness (R a ) of each specimen and the data was used for analysis of variance (ANOVA). There was no significantly statistical difference between groups for both of the one-step polishing systems (p > 0.05). The Astrobrush system presented R a values statistically lower than Optrapol system (p < 0.05). Twenty cycles of autoclaving, did not affect the surface roughness produced by polishing systems on the resin composite evaluated.
To assess the influence of material/technique selection (direct vs. CAD/CAM inlays) for large MOD... more To assess the influence of material/technique selection (direct vs. CAD/CAM inlays) for large MOD composite adhesive restorations and its effect on the crack propensity and in vitro accelerated fatigue resistance. A standardized MOD slot-type tooth preparation was applied to 32 extracted maxillary molars (5mm depth and 5mm bucco-palatal width) including immediately sealed dentin for the inlay group. Fifteen teeth were restored with direct composite resin restoration (Miris2) and 17 teeth received milled inlays using Paradigm MZ100 block in the CEREC machine. All inlays were adhesively luted with a light curing composite resin (Filtek Z100). Enamel shrinkage-induced cracks were tracked with photography and transillumination. Cyclic isometric chewing (5 Hz) was simulated, starting with a load of 200 N (5000 cycles), followed by stages of 400, 600, 800, 1000, 1200 and 1400 N at a maximum of 30,000 cycles each. Samples were loaded until fracture or to a maximum of 185,000 cycles. Teeth restored with the direct technique fractured at an average load of 1213 N and two of them withstood all loading cycles (survival=13%); with inlays, the survival rate was 100%. Most failures with Miris2 occurred above the CEJ and were re-restorable (67%), but generated more shrinkage-induced cracks (47% of the specimen vs. 7% for inlays). CAD/CAM MZ100 inlays increased the accelerated fatigue resistance and decreased the crack propensity of large MOD restorations when compared to direct restorations. While both restorative techniques yielded excellent fatigue results at physiological masticatory loads, CAD/CAM inlays seem more indicated for high-load patients.
Journal of Esthetic and Restorative Dentistry, 2012
Background: The translucency of enamel shade is a crucial property that affects the color of a la... more Background: The translucency of enamel shade is a crucial property that affects the color of a layered restoration.
Uploads
Papers by Hamilton Maia