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Objective@#To explore the clinical effect of bulk-fill composite resin combined with transparent preformed crowns for aesthetic restoration of deciduous incisor of children.@*Methods@#A predesigned clinical prospective randomized controlled research method was used to select 90 patients (123 teeth). The random number table method was divided into three groups: A, B, and C. Group A was treated with a bulk-fill composite resin of SF (SonicFill) combined with a transparent preformed crown (41 teeth in 30 cases), and group B was treated with a large block of Tetric N-Ceram Bulk Fill Composite resin combined with transparent preformed crowns (39 teeth in 29 cases). Group C was treated with 3M Z350 XT universal nano resin combined with transparent preformed crowns (43 teeth in 31 cases). The visual analog scale (VAS) and the modified USPHS standard were used to evaluate the completeness, marginal steps, marginal discoloration, surface condition, secondary caries and satisfaction of the parents with prostheses after 12 months.@*Results @#Twelve months after the operation, the evaluation indexes of group A were better than those of group B and group C, and the differences were statistically significant, including edge integrity (χ2=10.847, P=0.028), edge step (χ2=7.799, P=0.020), edge discoloration (χ2=10.391, P=0.034), surface state (χ2=11.476, P=0.021), and secondary caries (χ2=10.447, P=0.034). The satisfaction of parents in group A on the overall contour (χ2=10.238, P=0.037), shape and texture (χ2=11.521, P=0.021) were better than those in group B and group C, and the differences were statistically significant. There was no significant difference in the evaluation of color satisfaction among the three groups (χ2=0.990, P=0.610).@* Conclusion@#SonicFill bulk-fill composite resin combined with transparent preformed crown is good for short-term aesthetic restoration of deciduous incisor, and parental satisfaction is high.
ABSTRACT
Abstract Objective This randomized and clinical trial aimed to evaluate the performance of a new restorative Glass Ionomer Cement (GIC) for the restoration of non-carious cervical lesions (NCCLs) of patients with systemic diseases compared with a posterior resin composite after 12 months. Methodology 134 restorations were placed at 30 patients presenting systemic diseases by a single clinician. NCCLs were allocated to two groups according to restorative system used: a conventional restorative GIC [Fuji Bulk (GC, Tokyo Japan) (FB)] and a posterior resin composite [G-ænial Posterior (GC, Tokyo Japan) (GP)] used with a universal adhesive using etch&rinse mode. All restorative procedures were conducted according to manufacturer's instructions. Restorations were scored regarding retention, marginal discoloration, marginal adaptation, secondary caries, surface texture, and post-operative sensitivity using modified United States Public Health Service (USPHS) criteria after 1 week (baseline), 6, and 12 months. Descriptive statistics were performed using chi-square tests. Cochran Q and Mc Nemar's tests were used to detect differences over time. Results After 12 months, recall rate was 93% and the rates of cumulative retention failure for FB and GP were 4.9% and 1.6% respectively. Both groups presented similar alpha rates for marginal adaptation (FB 86.2%, GP 95.5%) and marginal discoloration (FB 93.8%, GP 97%) at 6-month recall, but FB restorations showed higher bravo scores than GP restorations for marginal adaptation and marginal discoloration after 12 months (p<0.05). Regarding surface texture, 2 FB restorations (3.1%) were scored as bravo after 6 months. All restorations were scored as alpha for secondary caries and postoperative sensitivity after 12 months. Conclusion Although the posterior resin composite demonstrated clinically higher alpha scores than the conventional GIC for marginal adaptation and discoloration, both materials successfully restored NCCLs at patients with systematic disease after a year. Clinical relevance Due to its acceptable clinical results, the tested conventional restorative GIC can be used for the restoration of NCCLs of patients with systemic diseases.
Subject(s)
Humans , Dental Restoration, Permanent , Glass Ionomer Cements , Follow-Up Studies , Dental Marginal Adaptation , Composite Resins , Resin Cements , Dental CariesABSTRACT
Objective: To investigate the effects of surface sealing on the shear bond strength(SBS) of the brackets. Methods: Twenty extracted premolars for orthodontics were cut into the buccofacial teeth pieces and etched by Transbond~TM Plus self-etching primers for 30 seconds firstly, then divided into two groups with 10 teeth pieces in each group randomly. ① experiment group, the buccal surface of the enamel was sealed with Filtek Flow 1400A3 flowable composite resin before bracket bonding;②control group, the bracket was bonded to the buccal surface of the enamel directly. All specimens were stored in deionized water at 37 ℃ for 48 h, thermocycled for 1 000 times at 30-second intervals between 5 ℃ and 55 ℃ water baths, and debonded with a universal testing machine. The amounts of resin remaining on the teeth pieces after debonding by using the resin remnant index (RRI), which were examined under 10×magnification stereo-microscope. Results: The SBS(MPa) between experiment group and control group was 8.08±1.38, 8.34±1.37 respectively, whereas the RRI was 2.80±1.03, 3.20±1.03 respectively. The SBS, RRI between experimental group and control group revealed no statistically significant differences. Conclusion: Surface sealing shows adequate bond strength, which is considered a clinically acceptable bond strength. The debonding of bracket is not affected by the surface sealing.
ABSTRACT
The purpose of this study was to investigate the effects of composite resin restorations on the stress distribution of notch shaped noncarious cervical lesion using three-dimensional (3D) finite element analysis (FEA). Extracted maxillary second premolar was scanned serially with Micro-CT (SkyScan1072; SkyScan, Aartselaar, Belgium). The 3D images were processed by 3D-DOCTOR (Able Software Co., Lexington, MA, USA). ANSYS (Swanson Analysis Systems, Inc., Houston, USA) was used to mesh and analyze 3D FE model. Notch shaped cavity was filled with hybrid or flowable resin and each restoration was simulated with adhesive layer thickness (40 microM). A static load of 500 N was applied on a point load condition at buccal cusp (loading A) and palatal cusp (loading B). The principal stresses in the lesion apex (internal line angle of cavity) and middle vertical wall were analyzed using ANSYS. The results were as follows 1. Under loading A, compressive stress is created in the unrestored and restored cavity. Under loading B, tensile stress is created. And the peak stress concentration is seen at near mesial corner of the cavity under each load condition. 2. Compared to the unrestored cavity, the principal stresses at the cemeto-enamel junction (CEJ) and internal line angle of the cavity were more reduced in the restored cavity on both load conditions. 3. In teeth restored with hybrid composite, the principal stresses at the CEJ and internal line angle of the cavity were more reduced than flowable resin.
Subject(s)
Adhesives , Bicuspid , Finite Element Analysis , Tooth , Tooth CervixABSTRACT
Statement of problem. Although many studies have been carried out to investigate the correlation between the degree of conversion and the flexural strength of composite resins, there is minimal information in the literature attempting to compare degree of conversion, flexural strength and their correlation between restorative composite resins and flowable composite resins. Purpose. The purposes of this study were to measure the degree of conversion and flexural strength of composite resins with different rheological behavior and to correlate the two properties. Materials and methods. Four restorative (Vit-l-escence, Z-250, Tetric ceram, Esthet-X) and four flowable (Aeliteflo, Admiraflow, Permaflo, Revolution) light-curing composite resins were investigated. The degree of conversion(DC) was analyzed with Fourier transfer infra-red spectroscopy(FTIR) spectrum by a potassium bromide(KBr) pellet transmission method. The spectrum of the unpolymerized specimen had been measured before the specimen was irradiated for 60s with a visible light curing unit. The polymerized specimen was scanned for its FTIR spectrum. The flexural strength(FS) was measured with 3-point bending test according to ISO 4049 after storage in water at 37 degree C for 24 hours. The data were statistically analyzed by an independent sample t-test and one-way ANOVA at the significance level of 0.05. The dependence of flexural strength on the degree of conversion was also analyzed by regression analysis. Results. Mean DC and FS values ranged from 43% to 61% and from 84.7MPa to 156.7MPa respectively. DC values of the flowable composite resins were significantly higher than those of restorative composite resins (P < 0.05). The FS values of restorative composite resins were greater than those of flowable composite resins. No statistically significant correlation was observed between the DC and the FS tested in any of the composites. The dependence of FS on DC in restorative or flowable composite resins was not significant. Conclusion. It can be concluded that radical polymerization of the organic matrix is not a major factor in determining flexural strength of the commercially available composite resins.
Subject(s)
Composite Resins , Light , Polymerization , Polymers , Potassium , Spectroscopy, Fourier Transform Infrared , WaterABSTRACT
The use of flowable composite resins as liners in class II packable composite restoration has been suggested by some manufacturers. However, the contributions of this technique are unproven. The purpose of this study was to compare the gingival microleakage in class II packable composite restorations with or without the use of flowable composite resins as liners. Slot cavities were prepared on both proximals of 80 extracted human molars and randomly assigned to 8 groups of 20 each. The gingival margins were located at 1mm above CEJ in 80 cavities (group1-4) and 1mm below CEJ in 80 cavities (group5-8). The prepared teeth were mounted in the customized tray with adjacent teeth to simulate clinical conditions and metallic matrix band (Sectional matrix) and wooden wedges were applied. After acid etching and application of Single Bond, each group was restored with the following materials using incremental placement technique: Group 1,5 (Filtek P60), group 2, 3, 4 and group 6, 7, 8 (AeliteFlo, TetricFlow, Revolution/Filtek P60). All specimens were thermocycled 500 times between 5degrees C and 55degrees C with 1 mimute dwell time, immersed 2% methylene blue dye for 24 hours and then rinsed with tab water. The specimens were embedded in clear resin and sectioned longitudinally through the center of restoration with a low speed diamond saw. Dye penetration at gingival margin was viewed at 20 magnification and analyzed on a scale of 0 to 4. Kruscal-Wallis One way analysis and Mann-Whitney Rank sum test were used to analyze the results. The results of this study were as follows. 1. The leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P0.05). 3. On the dentin margin, four groups demonstrated moderate to severe leakage, and there were no significant differences in leakage values(P>0.05).