Résumé
Complicated crown fractures of maxillary anterior teeth caused by trauma in adolescence can cause functional and aesthetic problems. For crown fractures with pulp exposure, various restorative methods can be considered depending on the amount of remaining tooth structure. Direct resin restorations are the most traditional and effective method, but they are likely to discolor and break over time. Fixed prosthesis have a high possibility of re-restoration due to marginal disharmony due to tooth movement during the growth period, and restorations using post which are mainly performed for extensive crown fractures increase the risk of root perforation and root fracture. However, endocrown is an integrated structure that gains retention force from the pulp space, enabling effective reconstruction from a biomechanical perspective and providing advantages in restoring function and aesthetics.Therefore, endocrown can be considered as a restoration method for complicated crown fractures caused by trauma in adolescence.
Résumé
Omnichroma (OMN) is a recently introduced structurally colored resin composite that expresses color based on the tooth structure surrounding the cavity. This study aims to investigate the effects of varying the cavity depth on the color blending of OMN.Conventional resin composite (Filtek Z250 in the A2, A3, and A4 shades) and structurally colored resin (Omnichroma) were used. Two types of specimens were prepared using custom silicone molds (diameter: 8 mm, thickness: 2, 3, 4 mm). Single specimens (diameter: 8 mm) comprised only Z250 in the A2, A3, A4 or OMN (n=10 each). Dual specimens comprised an outer ring (diameter : 8 mm) of Z250 in the A2, A3, or A4 and an inner hole (diameter: 4 mm) filled with OMN to different depths (1, 2, 3, or 4 mm, n=10 per shade per thickness). The colors were measuredusing the Commission Internationale d’Eclairage (CIE) L*a*b* system. Color differences (ΔE) according to the cavity depth and translucency parameter were measured.The ΔE values of dual specimens with the A2, A3, and A4 shades of Z250 were 1.66–5.07, 0.50–2.57, and 1.26– 3.48, respectively. At the same specimen thickness, ΔE increased with increasing cavity depth. At the same cavity depth, ΔE increased with decreasing thickness of the bottom of the restoration. The highest translucency parameterwas observed for 2 mm-thick OMN. The color blending of OMN increased with decreasing cavity depth in specimens of the same thickness, and with increasing bottom thickness of the restoration at the same cavity depth.
Résumé
Dental trauma is very common in children and relatively young people, with the line of treatment depending on the time elapsed, age of the child, and tooth maturity. If the fractured segment is available and there is close approximation of the segment to the remaining tooth, reattachment of the fractured segment is a feasible option. This treatment offers several advantages, including the reestablishment of function, aesthetics, shape, shine and surface texture, in addition to the original contour and alignment of the teeth. The following cases present two different complex crown fracture cases that were treated using tooth fragment reattachment with fiber-reinforced composite post.
Résumé
Calcium hydroxide has been widely used for root canal dressing material in endodontic treatment. This report describes that when the accurate diagnosis and proper nonsurgical endodontic retreatment is applied to periapical lesion with accidentally extruded calcium hydroxide paste, the lesion can be successfully treated. Overfilled calcium hydroxide can affect the healing process, so the overextension of calcium hydroxide agent should be avoided.
Résumé
Universal adhesives that simplify bonding procedures and be used in multi-etch mode have been developed. In this study, the effects of agitation and solvent evaporation time of a universal adhesive on microtensile bond strength (µTBS) were evaluated by varying the times of these two procedures. Eighteen human molars were used to fabricate specimens, and the teeth were randomly divided into six experimental groups. Each group had different agitation time (5 s, 10 s, 20 s) and evaporation time (10 s, 20 s). The specimens were cut into a rod-shape with a cross-sectional area of 1 mm2 , and their µTBS was measured. The data were analyzed using an ANOVA and Tukey’s post hoc test. After this, the debonded surface was observed using scanning electron microscopy (SEM). In the groups with a solvent evaporation time of 20 s, µTBS was statistically higher, even with a short agitation time (p<0.05). Furthermore, for the groups with the shorter evaporation time, bonding strength decreased statistically as the agitation time shortened (p<0.05). The results of this experiment suggest that if the solvent was adequately evaporated, sufficient bonding strength could be obtained even when the adhesive was agitated for a short time. This is supported by the results of SEM image analysis, which revealed a uniform adhesive layer with well-infiltrated tags in the groups with the prolonged evaporation time. It may be crucial to secure an adequate evaporation time in order to obtain optimal bonding strength.
Résumé
Universal adhesives that simplify bonding procedures and be used in multi-etch mode have been developed. In this study, the effects of agitation and solvent evaporation time of a universal adhesive on microtensile bond strength (µTBS) were evaluated by varying the times of these two procedures. Eighteen human molars were used to fabricate specimens, and the teeth were randomly divided into six experimental groups. Each group had different agitation time (5 s, 10 s, 20 s) and evaporation time (10 s, 20 s). The specimens were cut into a rod-shape with a cross-sectional area of 1 mm2 , and their µTBS was measured. The data were analyzed using an ANOVA and Tukey’s post hoc test. After this, the debonded surface was observed using scanning electron microscopy (SEM). In the groups with a solvent evaporation time of 20 s, µTBS was statistically higher, even with a short agitation time (p<0.05). Furthermore, for the groups with the shorter evaporation time, bonding strength decreased statistically as the agitation time shortened (p<0.05). The results of this experiment suggest that if the solvent was adequately evaporated, sufficient bonding strength could be obtained even when the adhesive was agitated for a short time. This is supported by the results of SEM image analysis, which revealed a uniform adhesive layer with well-infiltrated tags in the groups with the prolonged evaporation time. It may be crucial to secure an adequate evaporation time in order to obtain optimal bonding strength.
Résumé
The purpose of this study was to evaluate the effect of different dentin surface treatments on the bond strength of self-adhesive resin cement (G-CEM one). Human permanent molars were sectioned horizontally and standard smear layer was created. Teeth were divided into 4 groups according to the treatment methods: 1) no treatment, 2) 10% polyacrylic acid treatment, 3) exclusive primer (G-CEM one primer) treatment, 4) polyacrylic acid + exclusive primer treatment. After surface treatment, composite resin blocks were cemented with G-CEM one. After storage, specimens were cut into bars to measure the microtensile bond strength. Measured data were statistically analyzed. Confocal laser scanning microscopy was used to observe the bonding interface of cemented surface. Polyacrylic acid surface treatment group showed significantly lower µTBS than other groups (p<0.05). µTBS of exclusive primer treated groups was significantly higher than the control group (p<0.05). As a result, the exclusive primer improved dentin-cement bond strength. Polyacrylic acid treatment alone had negative effect on µTBS of G-CEM one and dentin.
Résumé
The purpose of this study was to evaluate the effects of deproteinization and an additional primer treatment on the microtensile bond strength of a newly developed self-adhesive resin cement to dentin. The occlusal dentin of extracted human third molars was randomly divided into four groups according to the surface treatment: a control (CON) with no treatment; applying a deproteinizing agent (DPT) (5% sodium hypochlorite); using a primer (PRI) (G-CEM ONE Adhesive enhancing primer, GC); and applying a deproteinizing agent and a primer (DPT-PRI). Composite resin blocks with a disk shape (diameter, 10 mm; height, 4 mm) were bonded to the treated dentin using a self-adhesive resin cement (G-CEM ONE, GC). The specimens were sectioned into sticks with a cross-section of 1 mm² and tested to failure in tension mode at a crosshead speed of 1 mm/min. All groups showed a significantly higher microtensile bond strength compared to CON (p0.05). Within the limitations of this study, a deproteinizing agent or specific primer can enhance the microtensile bond strength of the self-adhesive resin cement to dentin. However, it is not recommended to use a primer in combination with the deproteinizing agents.
Sujets)
Humains , Adhésifs , Dentine , Dent de sagesse , Céments résine , Sodium , Hypochlorite de sodiumRésumé
Crown fractures are the most frequent traumatic injuries to permanent teeth and mainly involve the maxillary incisors due to their exposed position in the dental arch. One option for managing crown fractures, when the tooth fragment is present and in good condition, is reattachment of the fragment to its original position. This paper reports on three crown fracture cases in which successful esthetic and functional results were achieved by reattachment of the tooth fragment.
Sujets)
Couronnes , Arcade dentaire , Incisive , DentRésumé
The purpose of this study was to examine effects of bioactive glass on Vickers hardness of bleached enamel surface. Enamel specimens were bleached with 15% carbamide peroxide (CP) for 14days. After bleaching, Artificial saliva (AS), 45S5 bioactive glass (BAG) and fluoride varnish (FV) are applied each specimens (n=10). The Vickers hardness of the specimens was measured before and after the bleaching, after the remineralized treatment at 1 day and after 7 and 14 days. The Vickers hardness on enamel surface after bleaching decreased statistically (p < 0.05) compared to before bleached enamel surface. The Vickers hardness increased significantly in the BAG and FV groups compared to the AS group values at 1 day and 7 days after remineralization (P < 0.05). 45S5 bioactive glass rapidly increase Vickers hardness of the bleached enamel surface.
Sujets)
Émail dentaire , Fluorures , Verre , Dureté , Peinture , Salive artificielle , UréeRésumé
The purpose of this study is to evaluate the compatibility of universal adhesives with two dual-cured resin cements. Eighty human molars were divided into eight groups. Tooth was embedded in self-curing acrylic resin and sectioned horizontally to exposure dentine surface. After polishing with 600-grit SiC paper, adhesives were applied. All-Bond Universal (Bisco), G-premio bond (GC), Scotch-bond universal (3M ESPE), Scotch-bond Multipurpose (3M ESPE) were used in this study. Calibra (Dentsply) as a conventional dual-curing resin cement and RelyX Ultimate (3M ESPE) as an amine free resin cement were used. The adhesives and the cements were applied according to the manufacturer's instructions. Final specimens were cylinder (diameter 2mm, height 3mm) shape. After storing in distilled water at 37℃ for 7 days the shear bond strength (SBS) test was performed. There was no significant difference in shear bond strength between the adhesives when RelyX Ultimate was used (p>0.05). However, when Calibra used with Scotch-bond Multipurpose and All-Bond Universal were used, statistically higher SBS was observed, as compared to the groups which Calibra cements with G-premio bond and Scotch-bond universal adhesive (p < 0.05) were used. Within the limitations of this study, RelyX Ultimate resin cement was compatible with universal adhesives of various pH. All-Bond Universal adhesive was compatible with a resin cement containing the tertiary amine.
Sujets)
Humains , Adhésifs , Dentine , Concentration en ions d'hydrogène , Molaire , Céments résine , Dent , EauRésumé
Anterior diastemas are common esthetic problems. One of the challenges in clinical esthetic dentistry is closing anterior diastemas without creating “black triangles” between the teeth. The success of a restorative treatment in anterior teeth depends on the esthetic integration between soft tissues and hard tissues. This report describes the successfully accomplished diastema closure case by producing the emergence profile with natural contours at the gingival-tooth interface and then generating of gingival recontouring process.
Sujets)
Odontologie , Diastème , DentRésumé
PURPOSE: The aim was to evaluate the effect of curing mode and different dentin surface pretreatment on microtensile bond strength (microTBS) of self-adhesive resin cements. MATERIALS AND METHODS: Thirty-six extracted human permanent molars were sectioned horizontally exposing flat dentin surface. The teeth were divided into 12 groups (3 teeth/group) according to the dentin surface pretreatment methods (control, 18% EDTA, 10% Polyacrylic acid) and curing mode (self-curing vs. light-curing) of cement. After pretreatment, composite resin blocks were cemented with the following: (a) G-CEM LinkAce; (b) RelyX U200, followed by either self-curing or light-curing. After storage, the teeth were sectioned and microTBS test was performed using a microtensile testing machine. The data was statistically analyzed using one-way ANOVA, Student T-test and Scheffe's post-hoc test at P<.05 level. RESULTS: For G-CEM LinkAce cement groups, polyacrylic acid pretreatment showed the highest microTBS in the self-cured group. In the light-cured group, no significant improvements were observed according to the dentin surface pretreatment. There were no significant differences between curing modes. Both dentin surface pretreatment methods helped to increase the microTBS of RelyX U200 resin cement significantly and degree of pretreatment effect was similar. No significant differences were found regarding curing modes except control groups. In the comparisons of two self-adhesive resin cements, all groups within the same pretreatment and curing mode were significantly different excluding self-cured control groups. CONCLUSION: Selecting RelyX U200 used in this study and application of dentin surface pretreatment with EDTA and polyacrylic acid might be recommended to enhance the bond strength of cement to dentin.
Sujets)
Humains , Dentine , Acide édétique , Molaire , Céments résine , DentRésumé
OBJECTIVES: This study examined the color changes of a resin composite with different shades upon exposure to water with different pH. MATERIALS AND METHODS: Nanohybrid resin composites (Filtek Z350XT, 3M ESPE) with four different shades (A2, A3, B1, and B2) were immersed in water with three different pH (pH 3, 6, and 9) for 14 day. The CIE L*a*b* color coordinates of the specimens were evaluated before and after immersion in the solutions. The color difference (DeltaE*) and the translucency parameter (TP) were calculated using the color coordinates. RESULTS: DeltaE* ranged from 0.33 to 1.58, and the values were affected significantly by the pH. The specimens immersed in a pH 6 solution showed the highest DeltaE* values (0.87 - 1.58). The specimens with a B1 shade showed the lowest DeltaE* change compared to the other shades. TP ranged from 7.01 to 9.46 depending on the pH and resin shade. The TP difference between before and after immersion in the pH solutions was less than 1.0. CONCLUSIONS: The resulting change of color of the tested specimens did not appear to be clinically problematic because the color difference was < 1.6 in the acidic, neutral, and alkaline solutions regardless of the resin shade, i.e., the color change was imperceptible.
Sujets)
Résines composites , Concentration en ions d'hydrogène , Immersion , EauRésumé
OBJECTIVES: This study examined the effects of additional acid etching on the dentin bond strength of one-step self-etch adhesives with different compositions and pH. The effect of ethanol wetting on etched dentin bond strength of self-etch adhesives was also evaluated. MATERIALS AND METHODS: Forty-two human permanent molars were classified into 21 groups according to the adhesive types (Clearfil SE Bond [SE, control]; G-aenial Bond [GB]; Xeno V [XV]; Beauti Bond [BB]; Adper Easy Bond [AE]; Single Bond Universal [SU]; All Bond Universal [AU]), and the dentin conditioning methods. Composite resins were placed on the dentin surfaces, and the teeth were sectioned. The microtensile bond strength was measured, and the failure mode of the fractured specimens was examined. The data were analyzed statistically using two-way ANOVA and Duncan's post hoc test. RESULTS: In GB, XV and SE (pH 0.05). In AU (pH = 3.2), additional etching increased the bond strength significantly (p < 0.05). When adhesives were applied to the acid etched dentin with ethanol-wet bonding, the bond strength was significantly higher than that of the no ethanol-wet bonding groups, and the incidence of cohesive failure was increased. CONCLUSIONS: The effect of additional acid etching on the dentin bond strength was influenced by the pH of one-step self-etch adhesives. Ethanol wetting on etched dentin could create a stronger bonding performance of one-step self-etch adhesives for acid etched dentin.
Sujets)
Humains , Adhésifs , Résines composites , Dentine , Éthanol , Concentration en ions d'hydrogène , Incidence , Molaire , DentRésumé
OBJECTIVES: This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites. METHODS: Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) L*a*b* system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to alpha = 0.05. RESULTS: The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness. CONCLUSIONS: Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk.
Sujets)
Humains , Champignons , Dureté , VénusRésumé
OBJECTIVES: This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites. METHODS: Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) L*a*b* system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to alpha = 0.05. RESULTS: The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness. CONCLUSIONS: Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk.
Sujets)
Humains , Champignons , Dureté , VénusRésumé
OBJECTIVES: This study examined the influence of the resin thickness on the polymerization of silorane- and methacrylate-based composites. MATERIALS AND METHODS: One silorane-based (Filtek P90, 3M ESPE) and two methacrylate-based (Filtek Z250 and Z350, 3M ESPE) composite resins were used. The number of photons were detected using a photodiode detector at the different thicknesses (thickness, 1, 2 and 3 mm) specimens. The microhardness of the top and bottom surfaces was measured (n = 15) using a Vickers hardness with 200 gf load and 15 sec dwell time conditions. The degree of conversion (DC) of the specimens was determined using Fourier transform infrared spectroscopy (FTIR). Scratched powder of each top and bottom surface of the specimen dissolved in ethanol for transmission FTIR spectroscopy. The refractive index was measured using a Abbe-type refractometer. To measure the polymerization shrinkage, a linometer was used. The results were analyzed using two-way ANOVA and Tukey's test at p < 0.05 level. RESULTS: The silorane-based resin composite showed the lowest filler content and light attenuation among the specimens. P90 showed the highest values in the DC and the lowest microhardness at all depth. In the polymerization shrinkage, P90 showed a significantly lower shrinkage than the rest two resin products (p < 0.05). P90 showed a significantly lower refractive index than the remaining two resin products (p < 0.05). CONCLUSIONS: DC, microhardness, polymerization rate and refractive index linearly decreased as specimen thickness linearly increased. P90 showed much less polymerization shrinkage compared to other specimens. P90, even though achieved the highest DC, showed the lowest microhardness and refractive index.
Sujets)
Résines composites , Éthanol , Dureté , Photons , Polymérisation , Polymères , Réfractométrie , Spectroscopie infrarouge à transformée de Fourier , Analyse spectraleRésumé
PURPOSE: The aim of this study was to evaluate the effects of additional acid etching and curing mechanism (light-curing or self-curing) of a composite resin on the dentin bond strength and compatibility of one-step self-etching adhesives. MATERIALS AND METHODS: Sixteen human permanent molars were randomly divided into eight groups according to the adhesives used (All-Bond Universal: ABU, Clearfil S3 Bond: CS3), additional acid etching (additional acid etching performed: EO, no additional acid etching performed: EX), and composite resins (Filtek Z-250: Z250, Clearfil FII New Bond: CFNB). Group 1: ABU-EO-Z250, Group 2: ABU-EO-CFNB, Group 3: ABU-EX-Z250, Group 4: ABU-EX-CFNB, Group 5: CS3-EO-Z250, Group 6: CS3-EO-CFNB, Group 7: CS3-EX-Z250, Group 8: CS3-EX-CFNB. After bonding procedures, composite resins were built up on dentin surfaces. After 24-hour water storage, the teeth were sectioned to make 10 specimens for each group. The microtensile bond strength test was performed using a microtensile testing machine. The failure mode of the fractured specimens was examined by means of an optical microscope at x20 magnification. The data was analyzed using a one-way ANOVA and Scheffe's post-hoc test (alpha=.05). RESULTS: Additional etching groups showed significantly higher values than the no additional etching group when using All-Bond Universal. The light-cured composite resin groups showed significantly higher values than the self-cured composite resin groups in the Clearfil S3 Bond. CONCLUSION: The additional acid etching is beneficial for the dentin bond strength when using low acidic one-step self-etch adhesives, and low acidic one-step self-etch adhesives are compatible with self-cured composite resin. The acidity of the one-step self-etch adhesives is an influencing factor in terms of the dentin bonding strength and incompatibility with a self-cured composite resin.
Sujets)
Humains , Adhésifs , Collodion , Résines composites , Ciments dentaires , Dentine , Agents de collage dentinaire , Molaire , Céments résine , Dent , EauRésumé
OBJECTIVES: The purpose of this study was to evaluate the effect of various application methods of one-step self-etch adhesives to microtensile resin-dentin bond strength. MATERIALS AND METHODS: Thirty-six extracted human molars were used. The teeth were assigned randomly to twelve groups (n = 15), according to the three different adhesive systems (Clearfil Tri-S Bond, Adper Prompt L-Pop, G-Bond) and application methods. The adhesive systems were applied on the dentin as follows: 1) The single coating, 2) The double coating, 3) Manual agitation, 4) Ultrasonic agitation. Following the adhesive application, light-cure composite resin was constructed. The restored teeth were stored in distilled water at room temperature for 24 hours, and prepared 15 specimens per groups. Then microtensile bond strength was measured and the failure mode was examined. RESULTS: Manual agitation and ultrasonic agitation of adhesive significantly increased the microtensile bond strength than single coating and double coating did. Double coating of adhesive significantly increased the microtensile bond strength than single coating did and there was no significant difference between the manual agitation and ultrasonic agitation group. There was significant difference in microtensile bonding strength among all adhesives and Clearfil Tri-S Bond showed the highest bond strength. CONCLUSIONS: In one-step self-etching adhesives, there was significant difference according to application methods and type of adhesives. No matter of the material, the manual or ultrasonic agitation of the adhesive showed significantly higher microtensile bond strength.