Clinical Performance of a Glass Hybrid Restorative in Extended Size Class II Cavities.

OBJECTIVE: To evaluate the clinical performance of a glass hybrid restorative compared with a resin composite in the restoration of large and deep Class II cavities after 24 months. METHODS AND MATERIALS: A total of 108 extended size, with the width of the proximal box not interfering with the peak of the cusps and the proximal box in occlusion, Class II lesions in 37 patients were either restored with a glass hybrid restorative or with a micro-hybrid composite resin in combination with selective etching by two experienced operators according to the manufacturer's instructions. Two independent examiners evaluated the restorations at baseline and at the six-, 12-, 18-, and 24-month recalls according to the modified US Public Health Service criteria. Negative replicas at each recall were observed under scanning electron microscopy (SEM) to examine surface characteristics. Data were analyzed statistically. RESULTS: After 24 months, 90 restorations were evaluated in 32 patients (recall rate: 86.5%). Four glass hybrid restorations were missing; three were due to bulk and one was due to proximal fracture at 12 months. Only six restorations were scored as bravo at baseline and at the six-, 12-, 18-, and 24-month recalls for color (p<0.05). No significant differences were observed between the two restorative materials for the other criteria evaluated (p>0.05). SEM observations exhibited acceptable surface and marginal adaptation characteristics for both restorative materials at 24 months. CONCLUSIONS: Although glass hybrid restorations showed significant mismatch in color, both restorative materials exhibited successful performance for the restoration of large Class II cavities after 24 months.

Repair potential of a new glass hybrid restorative system.

BACKGROUND: Repair of a failed amalgam or composite resin (CR) restoration has been extremely studied and proposed as a routine clinical treatment option; however, repair potential of glass ionomer-based restorative materials was not studied sufficiently in the literature. AIM: The aim of this study is to evaluate the repair potential of a glass hybrid (GH) restorative repaired either by the same material (GH) or CR after different surface treatments using microtensile bond strength (µTBS) test. METHODS AND MATERIALS: One hundred and twenty bar-shaped (2 × 2 × 8 mm) GH blocks were prepared. After aging, the specimens were divided into two groups (n = 60) and five subgroups (n = 12). The specimens in Group I were repaired with the following protocols: (a) no treatment + GH, (b) diamond bur (B) + GH, (c) cavity conditioner + GH, (d) cavity conditioner + universal adhesive (A) + GH, (e) A + GH, and specimens in Group II were repaired with (a) no treatment + CR, (b) B + CR, (c) B + A + CR, (d) 40% phosphoric acid + A + CR, (e) A + CR. The specimens that were subjected to µTBS testing, scanning electron microscopy evaluations, and fracture modes were determined. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests (P = 0.05). RESULTS: Repair using CR resulted in higher bond strengths (P < 0.001). The lowest bond strength was obtained in Group Ie. The highest bond strength was obtained when GH was roughened in Group IIc. CONCLUSION: Repair of restorative GH with CR appears as a preferred option to improve the bond strength.

Mechanical performance of a newly developed glass hybrid restorative in the restoration of large MO Class 2 cavities.

OBJECTIVE: To evaluate the mechanical properties of a glass hybrid (GH) restorative system (EQUIA Forte/GC) and compare it with a microhybrid composite (G-aenial Posterior/GC) by compressive strength (CS) and fracture resistance (FR) tests. MATERIALS AND METHODS: Cylindrical specimens were subjected to a CS test (n = 12). There were about 48 mandibular molars were used for a FR test and divided into four groups: Group 1 (positive control), sound teeth; Group 2 (negative control), extended size Class 2 cavities prepared on the mesial surfaces of teeth; Group 3, extended size Class 2 cavities restored with a composite; and Group 4, extended size Class 2 cavities restored with GH. Specimens were subjected to loading until a fracture occurred. Data were analyzed statistically (α = 0.05). RESULTS: The fracture modes were examined by scanning electron microscope (SEM). The CS values of the composite and GH were 278.20 ± 17.34 MPa and 164.62 ± 25.72 MPa, respectively (P < 0.05). No differences were observed between the FR of restored groups (P > 0.05). CONCLUSIONS: The GH exhibited sufficient mechanical properties as a restorative material, and could be preferred for extensive caries lesions on posterior teeth.

Comparison of two different composite resins used for tooth reshaping and diastema closure in a 4-year follow-up.

AIMS: This aim of this study is to evaluate and to compare the clinical performances of two nanohybrid composite resin systems used for diastema closure and tooth reshaping at 4 years. SUBJECTS AND METHODS: Twenty-three patients with midline or multidiastema problem were enrolled in this study. Nanohybrid resin composite systems to be used on each patient were randomly selected. Thirty seven teeth of 10 patients were restored with Filtek-Z550 (3M/ESPE) in combination with Adper™ Single Bond 2 (3M/ESPE) etch and rinse adhesive in Group 1 whereas 39 teeth of 13 patients were restored with Charisma-Diamond (Heraeus Kulzer) in combination with Gluma2 Bond (Heraeus Kulzer) etch and rinse adhesive in Group 2, by two operators. Esthetic, functional, and biological properties of the restorations were evaluated at baseline, 1, 2, 3, and 4 years using foreign direct investment criteria by two independent examiners. STATISTICAL ANALYSIS USED: The data were evaluated using Fisher's Chi-Square (P = 0.05). RESULTS: Fifty-eight restorations (19 patients) with a mean service time of 43.4 months were evaluated (recall rate 82.6%). One Filtek-Z550 and two Charisma-Diamond restorations were repaired due to partial fracture (Score 4). Survival rates of Group 1 and Group 2 were 96.3% and 93.5%, respectively (Kaplan-Meier) (P > 0.05). Qualitative deteriorations were observed within each group according to baseline regarding surface luster, surface/marginal staining, marginal adaptation, patient's view, and periodontal response (P < 0.05). However, there were no significant differences between two restorative materials for any of the criteria assessed (P > 0.05). CONCLUSIONS: Both nanohybrid composite resin systems revealed esthetically, functionally, and biologically acceptable clinical performance when used for diastema closure and tooth reshaping at 4 years.

Criteria for the Replacement of Restorations: Academy of Operative Dentistry European Section.

The replacement of a restoration is one of the most common procedures in dentistry. However, the criteria for such intervention, excluding catastrophic failure and persistent discomfort and pain, continue to be the subject of considerable debate. The decision-making process remains subjective on the part of the treating clinician, while the evidence base for refurbishment and repair rather than replacement for the management of defective and failing restorations continues to grow and strengthen. This article, prepared as an Academy of Operative Dentistry European Section consensus publication, reviews existing criteria for the replacement of restorations and encourages practitioners to shift, if not already doing so, to considering the replacement of a restoration as a last resort rather than as a prudent action to be taken if in any doubt about clinical acceptability. Further research in the area, spanning the risk assessment of defective and failing restorations and new diagnostic tools and processes, together with work to enhance the evidence base of restoration repair vs replacement, would be of immense value.

Four-year randomized clinical trial to evaluate the clinical performance of a glass ionomer restorative system.

OBJECTIVE: The aim of this study was to evaluate the clinical performance of a glass ionomer restorative system compared with a microfilled hybrid posterior composite in a four-year randomized clinical trial. METHODS: A total of 140 (80 Class 1 and 60 Class 2) lesions in 59 patients were either restored with a glass ionomer restorative system (Equia, GC, Tokyo, Japan), which was a combination of a packable glass ionomer (Equia Fil, GC) and a self-adhesive nanofilled coating (Equia Coat, GC), or with a microfilled hybrid composite (Gradia Direct Posterior, GC) in combination with a self-etch adhesive (G-Bond, GC) by two experienced operators according to the manufacturer's instructions. Two independent examiners evaluated the restorations at baseline and at one, two, three, and four years postrestoration according to the modified US Public Health Service criteria. Polyvinyl siloxane impression negative replicas at each recall were observed under scanning electron microscopy (SEM) to evaluate surface characteristics. The statistical analyses were carried out with McNemar, Pearson Chi-square, and Cochran Q-tests (p<0.05). RESULTS: After four years, 126 (76 Class 1 and 50 Class 2) restorations were evaluated in 52 patients, with a recall rate of 88.1%. None of the restorations showed trends to downgrade in anatomical form, secondary caries, surface texture, postoperative sensitivity, and color match (p>0.05). Significant differences in marginal adaptation and discoloration were found at four years compared to baseline for both restorative materials for Class 1 and Class 2 restorations (p<0.05). Only one Class 2 Equia restoration was missing at three years (3.9%), and another one was missing at four years (7.7%) (p>0.05). SEM evaluations were in accordance with the clinical findings. CONCLUSIONS: The use of both materials for the restoration of posterior teeth exhibited a similar and clinically successful performance after four years.

The effect of bleaching systems on the gingiva and the levels of IL-1ß and IL-10 in gingival crevicular fluid.

OBJECTIVE: This study aimed to evaluate the color change and clinical periodontal parameters and to analyze the interleukin­1 beta (IL-1ß) and interleukin-10 (IL-10) levels in gingival crevicular fluid (GCF) of patients treated with different bleaching systems. MATERIALS AND METHODS: According to pre-established criteria, 30 healthy volunteers were selected and randomly divided into three groups (n=10): G1, home bleaching (Opalescence 35% Carbamide Peroxide, CP); G2, chemically activated office bleaching (Opalescence Xtra Boost 38% Hydrogen Peroxide, HP); G3, light-activated office bleaching (Opalescence Xtra 35% HP). Treatments were applied according to the manufacturer's recommendations. After shade evaluation, clinical periodontal parameters were evaluated as follows: gingival index (GI), plaque index (PI), and bleeding on probing (BOP). GCF were collected from six maxillary sites per patient at baseline (T0), one day (T1) after bleaching treatments, and 15 days (T2) after bleaching treatments and analyzed for IL-1ß and IL-10 by enzyme-linked immunosorbent assay. Data were subjected to statistical analysis (p<0.05). RESULTS: Spectrophotometer readings exhibited significant differences among the groups (p<0.05). The ΔE values (color change) of G3 were statistically higher than the other groups (p<0.05). The PI of G3 after 15 days was significantly higher than the PI of G2 after 15 days (p<0.05). The GI of G2 was lower than that of G1 and G3 before bleaching (p<0.05). According to BOP, no significant differences were found among the groups at any time intervals (p>0.05). In G3, the total amount of IL-1ß after 15 days was higher than the amount before bleaching (p<0.05). The IL-10 total amount and concentration levels did not exhibit any significant differences among the groups or by time (p>0.05). CONCLUSION: Home and chemically activated bleaching systems could be considered as safer in tooth whitening and maintaining gingival health when compared with a light-activated bleaching system, which might lead to increased proinflammatory cytokine (IL-1ß).

Chemical analysis of enamel and dentin following the application of three different at-home bleaching systems.

PURPOSE: To determine the change in the chemical composition of enamel and dentin as well as to evaluate the differences in surface texture of the same dental hard tissues following three at-home bleaching systems in vitro. METHODS: Sixty extracted intact human anterior teeth were used in this study. Thirty teeth were used as samples for enamel, and the buccal surfaces of the remaining 30 teeth were abraded and used as dentin samples. Prior to bleaching treatments, calcium (Ca), phosphorus (P), potassium (K), sodium (Na), magnesium (Mg), fluoride (F), and oxygen (O) levels of each sample were measured using an energy dispersive spectrometer. The teeth were then randomly allocated into three groups according to the bleaching system used, as follows: GI, 10% carbamide peroxide (CP); GII, 20% CP; GIII, and 35% CP. Following the bleaching treatments, Ca, P, K, Na, Mg, F, and O measurements were repeated. The surface configurations were examined using scanning electron microscopy (SEM). The data were analyzed using Wilcoxon signed rank and Kruskal-Wallis tests followed by the Dunn test. RESULTS: All three bleaching systems tested caused similar changes in the chemical composition of enamel and dentin. Bleaching systems decreased Ca and K, while F and O levels increased in enamel. In dentin, Ca, P, and K levels decreased; however, Na, F, and O levels increased. SEM observations revealed no deleterious effect on enamel and dentin. CONCLUSION: The use of home bleaching agents could affect the chemical composition of dental hard tissues, whereas the change in the chemical composition of enamel and dentin was not affected by the CP concentration of the bleaching systems used.

Effects of erbium:yttrium-aluminum-garnet and neodymium:yttrium-aluminum-garnet laser hypersensitivity treatment parameters on the bond strength of self-etch adhesives.

This in vitro study evaluated the shear bond strength (SBS) of two self-etch adhesives to coronal and root dentin treated with erbium:yttrium-aluminum-garnet (Er:YAG) or neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers for dentin hypersensitivity. The coronal and root dentin surfaces of 60 extracted human cuspids were divided into three groups (n = 20): (1) control (without treatment); (2) treated with Er:YAG; (3) treated with Nd:YAG laser and a one-step (S3) or two-step self-etch adhesive (SE). A nano-composite was applied and SBS tests were performed. The mean SBS values were calculated, failure modes were determined, and data were subjected to statistical analysis (P = 0.05). Control/SE exhibited higher values than did control/S3 and Nd:YAG/S3 on coronal dentin (P < 0.05). No significant differences were observed between the SE and S3 groups in root dentin (P > 0.05). Comparisons of two dentin substrates did not show any difference except control/SE (P < 0.05). The failure modes were mainly adhesive. The SBSs of self-etch adhesives to Er:YAG or Nd:YAG laser-treated surfaces were comparable with control for both coronal and root dentin.

Effects of three concentrations of carbamide peroxide on the structure of enamel.

Carbamide peroxide bleaching agents have raised important questions on their potential adverse effects on the structure of enamel. The purpose of this study was to examine the effects of three carbamide peroxide bleaching agents in different concentrations (10, 16 and 35%) on the structure of enamel. Forty enamel slabs prepared from human third molars were divided equally among four groups. The specimens in the first and second group were subjected to 10% or 16% carbamide peroxide for 8 h per day for 6 weeks. Thirty-five percent carbamide peroxide was applied to the third group for 30 min a day for a 4 day period according to the manufacturers recommendation. The fourth group served as the control and was kept in artificial saliva during the test period. At the completion of the treatment, all the specimens were examined by infrared absorbtion spectroscopy and X-ray diffraction analysis. The results revealed that 10% or 16% carbamide peroxide did not seem to effect the structure of enamel, whereas 35% carbamide did affect the structure. The use of lower concentrations of carbamide peroxide (10-16%) is recommended over higher concentrations (35%) to avoid changes to the enamel.

Effect of disinfectant application methods on the bond strength of composite to dentin.

The use of cavity disinfectants with composite resins has raised important questions regarding their potential adverse effects on bond strength. The purpose of this study was to evaluate the effect of cavity disinfection on the bond strength of composite resin to dentin. Buccal surfaces of 64 caries-free extracted human third molars were ground flat by diamond flat-end cylinder bur, polished with a series of silicon carbide abrasive papers and mounted in autopolymerizing acrylic resin. They were randomly distributed into four groups (of 16). In group 1 (control group), dentin surfaces were treated with 35% phosphoric acid, Permagen primer and Permagen bonding resin and no disinfectant was used. In group 2, cavity disinfectant was applied and acid etching, priming and bonding procedures were performed as in group 1. In group 3, cavity disinfectant was applied after acid etching. In group 4, cavity disinfectant was applied as in group 3, but it was rinsed off before priming and bonding procedures. Then a Teflon mould 3 mm thick and 4 mm in diameter was attached to the dentin surfaces, filled with composite resin and light polymerized. After the specimens had been thermocycled, shear bond strengths were determined. Application of the disinfectant before or after acid etching significantly reduced the shear bond strength of composite to dentin (P<0.05). Rinsing off the cavity disinfectant before the bonding procedure did not affect the bond strength (P>0.05). The use of cavity disinfectant with composite resin restorations can influence the dentin bond strength.

Two-year performance of glass-ceramic insert-resin composite restorations: clinical and scanning electron microscopic evaluation.

OBJECTIVE: This study evaluated the 2-year clinical performance of beta-quartz-resin composite restorations. METHOD AND MATERIALS: Twenty-two glass insert-resin composite restorations were placed. Restorations were placed in 6 molars, 12 premolars, and 4 incisors. After 2 years, clinical assessment of the restorations was made by three operators according to the US Public Health Service criteria. Scanning electron microscopic evaluations were made by replica technique. RESULTS: Nineteen restorations were graded Alfa and three restorations were graded Bravo for color match. Twenty-one restorations were graded Alfa and one restoration Charlie for proximal contact, marginal integrity, and anatomic form. None of the restorations showed marginal discoloration, tooth sensitivity, or caries. CONCLUSION: Glass-ceramic insert-resin composite restorations exhibited excellent performance after 2 years of clinical service.

In vitro adherence of bacteria to bleached or unbleached enamel surfaces.

The purpose of this in vitro study was to evaluate the effects of three 10% carbamide peroxide bleaching agents on adherence of bacteria to tooth enamel surface. Enamel specimens were subjected to one of three carbamide peroxide solutions for 8 h per day for 30 days. Control specimens were kept in saline solution. Profilometer evaluation of surface roughness was performed on all specimens. The adherence of Streptococcus mutans was determined bacteriologically. There was no significant difference in surface roughness between the untreated and treated enamel specimens but a statistically significant difference was found in the adherence of S. mutans to bleached and unbleached enamel specimens. Specimens treated with Opalescence showed the highest adherence.

In vitro effects of alcohol-containing and alcohol-free mouthrinses on microhardness of some restorative materials.

Daily application of mouthrinses has been recommended for the prevention and control of caries and periodontal disease. The aim of this study was to evaluate the effect of alcohol-containing and alcohol-free mouthrinses on the microhardness of three restorative materials. Materials tested included visible light cured (VLC) composite resin (Amelogen), VLC glass-ionomer cement (Fuji II LC) and a fissure sealant (Ultra Seal XT). Eighteen cylinders of each restorative were fabricated and initially stored in distilled water for 24 h. Six samples of the restoratives were stored for 12 hours to simulate a 2 min/day for 1 year exposure to mouthrinses in the following solutions: distilled water (control), alcohol-containing mouthrinse (Viadent) and alcohol-free mouthrinse (Rembrandt). At the end of the test period microhardness was measured with a Tukon microhardness tester. Kruskal-Wallis one-way analysis of variance was used to analyse the data. Both mouthrinses affected the hardness of the materials tested.

Antibacterial activity of 10% carbamide peroxide bleaching agents.

The antibacterial activity of three commercial 10% carbamide peroxide bleaching agents (Nite White, Karisma, and Opalescence) on Streptococcus mutans, Streptococcus mitis, Streptococcus sanguis, Lactobacillus casei, and Lactobacillus acidophilus was examined. Chlorhexidine (0.2%) was used as a positive control. Test materials and control solution were inserted in wells punched on the surface of disk sensitivity agars seeded with bacteria. After incubation of 24 to 48 h, zones of inhibition were measured. All three of the test materials displayed greater inhibition than the control. The pH of the solutions did not effect the bacterial inhibition.

Marginal seal of a resin-modified glass-ionomer restorative material: an investigation of placement techniques.

This study examined marginal seal of a visible resin-modified glass-ionomer restorative material. Class V cavity preparations in extracted human premolars were restored with one of four different placement techniques: bulk placement, vertical incremental placement, incremental placement with the gingival increment placed first, or incremental placement with the occlusal increment placed first. Either a cervical former or a hand instrument was used to contour the restorations. Measurement of dye penetration indicated that there was no statistically significant differences in microleakage among the groups, by placement technique or method of contouring. However, two groups contoured with a cervical former were found to be 100% leakage free.

[Bacteriological investigation of the cariogenic effects of sugar alcohols and sucrose]. / Seker alkolleri ve sukrozun çürük yapici etkilerinin bakteriyolojik yöntemlerle arastirilmasi.

Considerable evidence indicates that the disaccharide, sucrose is probably the major dietary factor in dental caries formation and much subsequent research has gone into the search for another sweetener to replace sucrose. Currently, there is much interest in the development of new sweeteners and the cariogenic properties of sugar alcohols. The present study aimed to examine the cariogenic properties of sugar alcohols (xylitol, sorbitol, mannitol) and sucrose on growth pattern and acid production of S. mutans, S. mitis, S. salivarius, S. sanguis, S. faecalis, S. viridans, L. casei and L. acidophilus in vitro by using Photo Electrical Colorimeter and pH meter. In conclusion the results in this study showed that out of sugar alcohols, xylitol is the only compound which, depending on its concentration, significantly did not affect the growth and acid production of all tested micro organisms.