Long-term clinical comparison of a resin-based composite and resin modified glass ionomer in the treatment of cervical caries lesions.

This 72-month study compared the clinical effectiveness of a resin-based composite (RBC) (Spectrum TPH3, Dentsply Sirona) with a resin-modified glass ionomer cement (RMGIC) (Riva Light Cure, SDI) in restoring cervical caries lesions (CCLs). Thirty-three patients, each with at least two CCLs, were enrolled. After caries removal, the dimensions of the cavities were recorded. In a split-mouth study design, a total of 110 restorations were randomly placed. Fifty-five restorations were placed with RBC using an etch-and-rinse adhesive system (Prime&Bond NT, Dentsply Sirona), while the remaining 55 were restored with RMGIC. The restorations were assessed at baseline, 6, 12, 18, 24, 36, 60, and 72 months according to modified USPHS criteria. Statistical analysis included Pearson Chi-square, Friedman tests, Kaplan Meier, and Logistic Regression analysis (p < 0.05). After 72 months, 47 restorations in 19 patients were evaluated (55% follow-up rate). Seventy-five percent of the RBC (n = 26) and 74% (n = 21) of the RMGIC restorations were fully retained. There were no significant differences between materials regarding retention and marginal adaptation (p > 0.05). Cavity dimensions, caries activity, and retention exhibited no correlation (p > 0.05). The increase in marginal staining in both groups over time was significant (p < 0.001). RMGIC restorations exhibited higher discoloration than RBC restorations (p = 0.014). At 72 months, three secondary caries lesions were detected in both restoration groups: two RMGIC and one RBC. There were no reports of sensitivity. After 72 months, both RBC and RMGIC restorations were clinically successful, with similar retention and marginal adaptation scores. However, it is noteworthy that RMGIC restorations tend to discoloration over time compared to RBC. The trial is registered in the database of "Clinical Trials". The registration number is NCT0372-2758, October 29, 2018.

Which is the most effective biomaterial in indirect pulp capping? 4- year comparative randomized clinical trial.

Purpose: The aim of this study is to compare the clinical outcomes of Mineral Trioxide Aggregate (MTA) and calcium hydroxide pulp capping after complete caries removal. Materials and methods: In 73 regular patients (47 women, 26 men; age 20.65±3.02 years), having at least one deep carious lesion was recruited. Following complete caries removal, the pulp was indirectly capped with either MTA(n=51) or calcium hydroxide (n =49), randomly. Final restoration with a resin-based composite in a single session was performed. Clinical parameters including pulp vitality, sensitivity to cold or heat stimulants, percussion tests and discomfort during chewing and color were recorded after 6 months, 1 year, 2- year, 3- year and 4- year. Data were analysed statistically (p<0.05). Results: After 4- year, the survival rates were 86% (for MTA), and 82.9% (for calcium hydroxide). Totally, 8 teeth from calcium hydroxide group and 7 teeth from MTA group were endodontically treated. No significant difference was detected between the groups in terms of pulp vitality (p=0.613). Grey discoloration rate was 63% in MTA group. Conclusion: Both pulp-capping materials, MTA and calcium hydroxide showed similar clinically successful performance in terms of pulp vitality in the treatment of deep dentin caries lesions after 4- year.

Clinical comparison of a micro-hybride resin-based composite and resin modified glass ionomer in the treatment of cervical caries lesions: 36-month, split-mouth, randomized clinical trial.

PURPOSE: The aim of the study was to compare the 36-month clinical performances of a micro-hybride resin based composites (RBC) and a type II resin modified glass ionomer cement (RMGIC) in the treatment of cervical caries lesions. METHODS: Thirty-three patients (23 females,  10 males) with at least two cervical caries lesions participated in this study. A total of 110 restorations were randomly placed, half using RBC (Spectrum TPH3, Dentsply Sirona) with respective adhesive system (Prime & Bond NT, Dentsply Sirona) the other half using the RMGIC (Riva Light Cure, SDI, Bayswater, Victoria, Australia). Restorations were assessed at baseline, and after 6, 12, 18, 24 and 36 months using modified USPHS criteria. The data were analyzed statistically (p < 0.05). RESULTS: Recall rate was 90.91% at 36 months. Of the RBC lesions 84.3% (n = 43) and of the RMGIC restorations 92.2% (n = 47) were fully retained at 36 months. There was no significant difference between two materials in terms of retention and marginal adaptation (p > 0.05). No relation was found between caries activity, cavity dimensions and marginal adaptation (p > 0.05) but RMGIC restorations showed significantly more discoloration than RBC restorations after 36 months (p < 0.001). CONCLUSIONS: Considering the middle-term outcomes, both materials showed clinically successful performance in the treatment of cervical caries lesions.

A comparison of cuspal movement of premolar teeth restored with bulk-filled composite resins combined with universal adhesives.

BACKGROUND: The aim of the present study was to compare bulk-filled composite resins with conventional composites in terms of cuspal movement and micro-leakage scores. METHODS: Ninety-six maxillary premolar teeth with mesial-occclusal-distal cavities were allocated to four groups. Twelve teeth in each group was treated etch-and-rinse, self-etch or selective-etch (N.=8) protocols with respective adhesive system. Bucco-palatal cusp measurements were performed before and after preparation, and 180s after curing and then subjected to 5000 thermocyclws. After immersed in 0.2% basic fuchsin dye for 24h, cervical micro-leakage was evaluated. The data was analyzed by One-way ANOVA and post-hoc Tukey's honest Test (P<0.05). RESULTS: All groups and bonding protocols revealed no significant differences in total cuspal deflection measurement and micro-leakage scores. After preparation, a significant increase was found in bucco-palatal width of the teeth compared to baseline (P=0.002). There were no significant relationship among composite resins and adhesives (P>0.05). CONCLUSIONS: Cuspal relief after cavity preparation should be taken into account when evaluating deflection.

Dopaminergic induction of human dental pulp stem cells by photobiomodulation: comparison of 660nm laser light and polychromatic light in the nir.

Human dental pulp stem cells (hDPSCs) are able to differentiate into dopaminergic neurons and help the maintenance of partially degenerated neurons, which makes them as an alternative cell source for treatment of Parkinsons' disease (PD) patients. Here, the effect of photobiomodulation with polychromatic light source in the near infrared (NIR) range (600-1200 nm) or low level 660 nm diode laser light on hDPSCs during dopaminergic induction was investigated. Real time RT-qPCR analysis indicated that expressions of brain derived neurotrophic factor (BDNF), glial cell line derived neurotropic factor (GNDF), matrix associated protein 2 (MAP2), nuclear receptor related 1 protein (NURR1) and dopamine transporter (DAT) were increased, especially in the first 7 days of dopaminergic induction when 660 nm laser light was applied with a total energy density of 1.6 J/cm2. The activity of polychromatic light on hDPSCs depended on the differentiation media and protein type. BDNF, GDNF, NURR-1 and MAP2 expressions were increased in the presence of pre-induction factors, and decreased when the post-induction factors were added into the culture medium. In contrast with all these promising results, the dopaminergically induced hDPSCs did not show any functional characteristics of dopaminergic neurons and died after they were transferred to a new laminin coated culture plates. In conclusion, the expression of dopaminergic neuron protective protein mRNAs in hDPSCs was increased by photobiomodulation in defined conditions. However, the cells were not able to differentiate into functional dopaminergic neurons either in control or in photobiomodulated groups that are prone to cell death and exhibit immature dopaminergic neuron characteristics.

Effectiveness of two desensitizing products: A 6-month randomized clinical, split-mouth study.

PURPOSE: This randomized controlled clinical trial compared the efficacy of a desensitizer containing calcium phosphate with a two-step self-etch adhesive and placebo over a 6-month period. METHODS: 50 subjects aged between 21-64 years with a sensitivity score of 6 or higher according to the Visual Analog Scale (VAS) in at least three teeth participated in this study. Teethmate Desensitizer, Clearfil SE Bond 2, and placebo (distilled water) were applied randomly to three teeth of each patient. Recall reviews were performed at baseline, 1 week, 1 month, 3 months, and 6 months after treatment, and the sensitivity scores were assessed by air-blast application. The normality of data was analyzed with Shapiro-Wilk. Since the placebo treatment was successful only in a small number of teeth, the three materials could only be compared 10 minutes after the treatment. Data were analyzed with Wilcoxon Test, Friedman and Dunn post-hoc tests (P= 0.05). RESULTS: Sensitivity decreased significantly after application for each of the three test groups when compared to the pretreatment condition (P< 0.05). There were no significant differences between the Teethmate Desensitizer and Clearfil SE Bond 2, and both materials were more effective than the placebo (P< 0.05). CLINICAL SIGNIFICANCE: Teethmate Desensitizer and Clearfil SE Bond 2 had similar desensitizing effects; both of them could be applied to treat dentin hypersensitivity for a 6-month period.

Effect of cavity lining on the restoration of root surface carious lesions: a split-mouth, 5-year randomized controlled clinical trial.

OBJECTIVE: To compare the clinical performance of cavities with no lining and lining with resin-modified glass ionomer (RMGIC) for the treatment of root surface carious lesions. MATERIALS AND METHODS: The study included 39 patients (mean age, 39.6 years) who visited the university hospital for the treatment of at least 2 root surface carious lesions. After caries removal, the depth, length, and height of the cavities were measured. Using a paired-tooth design and simple randomization technique, the cavities were assigned to one of two groups that were either unlined or lined with RMGIC (Glass Liner II). All cavities were restored with a nanohybrid resin-based composite (Clearfil Majesty Esthetic). One hundred restorations (50 lined, 50 unlined) were placed. Two examiners other than the operator blindly evaluated the restorations at the follow-ups according to the modified Havemann criteria for marginal adaptation, anatomic form, marginal staining, caries in the adjacent tooth structure, caries at the cavosurface margin, and tooth sensitivity. Chi-square, Fisher's exact, Mann-Whitney U, and Cochran Q tests were used for the analysis (p < 0.05). RESULTS: At the 5-year follow-up, 12 restorations were failed. However, there was no significant difference between the marginal adaptation and marginal staining of the materials (p = 0.526 and p = 0.893, respectively). Four caries lesions were detected in the adjacent tooth structure and at the cavosurface margin at the 5-year assessment. CONCLUSION: There was no significant difference in the clinical performance of the lined and unlined restorations. CLINICAL RELEVANCE: The clinical performance of both unlined and RMGIC-lined cavities at the 5-year post-restoration assessment was acceptable. TRIAL REGISTRATION: NCT03802539.

Chitosan-based double-faced barrier membrane coated with functional nanostructures and loaded with BMP-6.

In the present study, a chitosan-based, multifunctional and double-faced barrier membrane was developed for the periodontitis therapy. The porous surface of the membrane was coated with bone-like hydroxyapatite (HA) produced by microwave-assisted biomimetic method and enriched with bone morphogenetic factor 6 (BMP-6) to enhance the bioactivity of chitosan. This surface of the membrane was designed to be in contact with the hard tissue that was damaged due to periodontitis. Otherwise the nonporous surface of membrane, which is in contact with the inflammatory soft tissue, was coated with electrospun polycaprolactone (PCL) fibers to prevent the migration of epithelial cells to the defect area. PrestoBlue, Scanning Electron Microscope (SEM) and real-time PCR results demonstrated that while porous surface of the membrane was enhancing the proliferation and differentiation of MC3T3-E1 preosteoblasts, nonporous surface of membrane did not allow migration of epithelial Madine Darby Bovine Kidney (MDBK) cells. The barrier membrane developed here is biodegradable and can be easily manipulated, has osteogenic activity and inactivity for epithelial cells. Thus, by implanting this membrane to the damaged periodontal tissue, bone regeneration will take place and integrity of periodontal tissues will be preserved.

Clinical Performance and Epidemiologic Aspects of Fractured Anterior Teeth Restored with a Composite Resin: A Two-Year Clinical Study.

PURPOSE: To investigate the etiologic factors, effect of age and gender on dental trauma, and to evaluate the performance of composite resin on the fractured crown of permanent anterior teeth. MATERIALS AND METHODS: Over a 2-year period, 73 permanent teeth from 51 patients with dental trauma were treated with direct composite resin restoration. Informed consent and standardized trauma forms were completed by the patient; teeth were restored with a submicron hybrid composite resin (Spectrum TPH) and respective adhesive system (Prime&Bond NT). Sixty-nine teeth were directly restored without fiber posts, while four were treated with fiber posts. Two experienced clinicians, besides the operator, evaluated each restoration at 6-, 12-, and 24-month follow-ups according to US Public Health Service (USPHS) criteria for the following characteristics: anatomical form, marginal adaptation, color match, marginal discoloration, surface roughness, and caries. Data were analyzed using the Wilcoxon Signed Rank, Kruskal-Wallis, Mann-Whitney U, and Siegel and Castellan tests. RESULTS: A total of 73 traumatized teeth in 51 patients aged from 14 to 64 years (mean age 25.47 ± 14.058 years) were assessed according to the Ellis classification and restored over a 2-year period. Crown fractures were more common in the maxilla (84.9%) and caused by falls (58.8%). At the end of 24 months, a total of ten restorations were lost. The survival rate after 24 months was 82.14%. There were statistically significant differences in marginal adaptation between the 6-, 12-, and 24-month follow-ups. Although changes in marginal discoloration over time were not significant (p = 0.194), changes in color match were significant (p = 0.029). CONCLUSION: Within the limitations of this study, direct composite restorations were accepted as clinically satisfactory.

Nanofilled and conventional resin-modified glass ionomer fillings combined with connective tissue grafts for treatment of gingival recessions with non-carious cervical lesions.

The aim of this study was to evaluate the clinical root coverage results of subepithelial connective tissue grafts (SCTG) performed on teeth with gingival recessions and non-carious cervical lesions (NCCLs) that were restored with cervical fillings and compare the results of two different filling materials: resin-modified glass ionomer (RMGIC) and nano-ionomer cements (NIC). A total of 54 teeth with Miller Class I gingival recessions with or without NCCLs in 36 patients (28 females, 8 males) were treated with SCTGs. Cervical lesions were randomly treated with RMGIC or NIC restorations. Periodontal clinical parameters, height of gingival recession (HGR), width of gingival recession (WGR), height of keratinized tissue, and dentin sensitivity were measured at baseline and 3, 6, and 12 months postoperatively. HGR and WGR values were statistically significantly reduced at all time points when compared to baseline values in all groups. There were no statistically significant differences between the groups in any clinical periodontal parameter (P > 0.05). The percentage of root coverage at 12 months was 89.5%, 90.1%, and 96.2% in the RMGIC, NIC, and control groups, respectively. Successful root coverage with connective tissue grafts may be achieved on teeth restored with RMGIC or NIC cervical fillings.

Spreading, proliferation and differentiation of human dental pulp stem cells on chitosan scaffolds immobilized with RGD or fibronectin.

Nowadays, human dental pulp stem cells (hDPSCs) became more attractive for therapeutic purposes because of their high proliferation and differentiation potential. Thus, coupling the desired cellular characteristics of hDPSCs with good biomaterial properties of the chitosan scaffolds provide an interesting approach for tissue engineering applications. On the other hand, scaffold surface modification is also needed to promote stem cell adhesion since chitosan lacks adhesion motifs to support direct cell anchorage. In this study, hDPSCs were isolated from third molars of healthy female individuals (aged 16-25) with enzymatic digestion. For cell culture studies, the chitosan scaffolds which have approximately 9 mm diameter and 2 mm thickness with interconnected structure were prepared by freeze-drying. To support cellular attachment the scaffolds were covalently immobilized with either RGD (arginine-glycine-aspartic acid) or fibronectin (Fn) molecules. Cells were seeded on chitosan scaffolds with or without immobilized RGD and fibronectin. Cell attachment, spreading, adhesion behaviors and proliferation capacity were examined by scanning electron microscopy, immunofluorescence staining and PrestoBlue® assays, respectively. In addition, differentiation potential of hDPSCs on Fn immobilized chitosan scaffolds was determined with real time reverse transcriptase polymerase chain reaction analysis. The results showed that chitosan scaffolds were not able to support stem cell attachment. hDPSCs on chitosan scaffolds formed spheroids more quickly and the size of spheroids were smaller than on chitosan-RGD while Fn-immobilized chitosan scaffolds strongly supported cellular attachment but not odontogenic differentiation. The results suggest that the Fn-immobilized chitosan scaffolds may serve as good three-dimensional substrates for dental pulp stem cell attachment and proliferation. In the case of dental regeneration, they must be supported by appropriate biosignals to induce odontogenic differentiation.

Bond strength of dental nanocomposites repaired with a bulkfill composite.

BACKGROUND: The aim of this study was to analyze the bond strength of aged resin based nanocomposites repaired with the same and bulk fill composites. MATERIAL AND METHODS: Seventy-two disc shaped resin composites consisted of three different nanocomposite resins (Filtek Ultimate/FU, Herculite XRV Ultra/HXRV, and Reflectys/R) were produced. After storing the samples for 8 weeks in distilled water, each material was combined with the same material or the bulk-fill composite resin system (Filtek Ultimate+Filtek Ultimate/Group-1; Filtek Ultimate+Tetric BF/Group-2; Herculite XRV+Herculite XRV/Group-3; Herculite XRV+Tetric BF/ Group-4; Reflectys+Reflectys/Group 5; Reflectys+Tetric BF/Group-6), for repair. Then specimens were subjected to shear bond strength testing(SBS), and the debonded surfaces were examined. RESULTS: There was a significant difference among three materials(repaired with itself+bulk fill) for SBS testing values (p=0.001). FU and R were found to be similar, while HXRV was significantly different from them. A significant difference between group-1 and 2 (p=0.006) was detected, while there were no differences between group 3 and 4 (p= 0.142), and 5 and 6 (p=0.346). Among the six groups, repair SBS testing values with TBF were higher than repair with itself except for FU. CONCLUSIONS: The bulk-fill repaired materials showed higher bond strength except for FU, which showed the highest SBS value when repaired with itself. An increased incidence of adhesive fracture was observed at low strengths. Key words:Resin-based composites, nanofillers, surface treatment, macro-shear, repair.

Polychromatic light-induced osteogenic activity in 2D and 3D cultures.

Photobiomodulation (PBM) has been applied to manipulate cellular responses by using monochromatic light in different wavelengths from ultraviolet (UV) to infrared (IR) region. Until now, an effective wavelength has not been revealed to induce proliferation and/or differentiation of cells. Therefore, in the presented study, we decided to use a specially designed plasma arc light source providing wavelengths between 590 and 1500 nm in order to investigate its biomodulatory effects on chitosan scaffold-supported three-dimensional (3D) cell cultures. For comparison, two-dimensional (2D) cell cultures were also carried out in tissue-culture polystyrene dishes (TCPS). The results showed that light-induced temperature rise did not affect cells when the distance between the light source and the cells was 10 cm and the frequency of administration was daily. Moreover, light was applied for 5 and 10 min to the cells in TCPS and in chitosan scaffold groups, respectively. Cell culture studies under static conditions indicated that polychromatic light significantly stimulated bone nodule formation via the prolonged cell survival and stimulated differentiation of MC3T3-E1 preosteoblastic cells in both TCPS and chitosan scaffold groups. In conclusion, specially designed plasma arc light source used in this study induces formation of bone tissue and so, this light source is proposed as an appropriate system for in vitro bone tissue engineering applications. Statistical analyses were performed with one-way ANOVA by using GraphPad Instat software and standard deviations were calculated by using data of three parallel samples for each group.

Etiologic factors and clinical evaluation of restored fractured anterior teeth: an observational study.

PURPOSE: The aims of this study were to investigate the etiologic factors and to evaluate performance of composite resin on fractured crown in permanent anterior teeth at 6 and 12 months. SUBJECTS AND METHODS: Records from 51 patients were retrieved from a Dental School Clinic, comprising 73 fractured anterior teeth directly restored with a submicron hybrid composite (Spectrum TPH) resin and respective adhesive system (Prime and Bond NT) were evaluated. The United States Public Health Service criteria were used to assess the clinical evaluation. Data were analyzed using the Wilcoxon Signed Rank, Kruskal-Wallis, Mann-Whitney U, and Siegel and Castellan tests. RESULTS: Seventy-two maxillary incisors and one canine of 51 patients were evaluated. The patient's age at the time of therapy ranged from 14 to 64 years old (mean 25.47). Mostly observed crown fracture was seen in upper incisors (84.9%) and due to falls (58.8%). At the 6-month follow-up, one patient lost one restoration and at the 12-month, one patient lost one and one lost two restorations. A statistically significant difference was found in terms of marginal adaptation between 6 and 12 months. CONCLUSION: In this short-term observation period, remaining tooth structure was conserved and good patient compliance was achieved. Factors such as esthetic and/or cost should be considered to indicate the direct composite restorations.

Effect of bleaching on mercury release from amalgam fillings and antioxidant enzyme activities: a pilot study.

OBJECTIVE: The aim of this pilot clinical study was to determine the mercury release from amalgam fillings and antioxidant enzyme activities (Superoxide Dismutase [SOD] and Catalase[CAT] ) in body fluids after exposure to two different vital tooth bleaching systems. MATERIAL AND METHODS: Twenty eight subjects with an average age of 25.6 years (18-41) having at least two but not more than four Class II amalgam fillings on each quadrant arch in the mouth participated in the study. Baseline concentrations of mercury levels in whole blood, urine, and saliva were measured by a Vapor Generation Accessory connected to an Atomic Absorption Spectrometer. Erythrocyte enzymes, SOD, and CAT activities in blood were determined kinetically. Subjects were randomly assigned to two groups of 14 volunteers. Group 1 was treated with an at-home bleaching system (Opalescence PF 35% Carbamide Peroxide, Ultradent), and Group 2 was treated with a chemically activated office bleaching system (Opalescence Xtra Boost 38% Hydrogen Peroxide, Ultradent) according to the manufacturer's recommendations. Twenty-four hours after bleaching treatments, concentrations of mercury and enzymes were remeasured. RESULTS: There were no significant differences on mercury levels in blood, urine, and saliva before and after bleaching treatments (p > 0.05). No differences were also found in the level of antioxidant enzyme activities (SOD and CAT) before and after treatments (p > 0.05). Mercury release did not affect the enzyme activities (p > 0.05). CONCLUSION: Bleaching treatments either office or home did not affect the amount of mercury released from amalgam fillings in blood, urine, and saliva and the antioxidant-enzyme activities in blood. CLINICAL SIGNIFICANCE: Bleaching treatments with the systems tested in this pilot study have no deleterious effect on the mercury release from amalgam fillings and antioxidant enzymes in body fluids.

Effect of Er,Cr:YSGG laser irradiation on the apical sealing ability of AH Plus/gutta-percha and Hybrid Root Seal/Resilon Combinations.

OBJECTIVE: The objective of this study was to evaluate the sealing ability of 2 different resin-based endodontic filling systems after smear layer removal with 2 different techniques. STUDY DESIGN: Extracted human single-rooted teeth (n = 74) were instrumented using HERO Shaper rotary instruments and irrigated with 1 mL of 2.5% NaOCl between each instrument. Additionally, the canals received either an extra 3-minute rinse with 2 mL of 17% EDTA or a 40-second Er,Cr:YSGG laser treatment. The root canals were filled with either Hybrid Root Seal/Resilon combination or AH Plus/gutta-percha combination using lateral condensation technique (n = 11). Apical leakage quantity was measured with the computerized fluid filtration meter at 1 and 4 weeks. One root from each group, which was not submitted to the fluid filtration test, was selected for scanning electron microscopy (SEM) analysis. Statistical analysis was performed using 3-way ANOVA and the post hoc Tukey HSD test (α = 0.05). RESULTS: A significant decrease was observed in the microleakage values of all the experimental groups tested with time (P < .0001). EDTA + AH Plus/gutta-percha combination exhibited the least microleakage, whereas laser irradiation + Hybrid Root Seal/Resilon combination showed the greatest microleakage at each of the 2 time periods. Each experimental combination exhibited architecture in SEM that seemed to correlate with its sealing performance. CONCLUSION: Er,Cr:YSGG laser treatment does not enhance the sealing ability of the sealers compared with EDTA application. The root canal adaptation and sealing ability of the Hybrid Root Seal/Resilon combination is not superior to that of the AH Plus/gutta-percha combination.

Effect of different adhesive systems and laser treatment on the shear bond strength of bleached enamel.

PURPOSE: This study determined the shear bond strength of a nanohybrid composite resin to bleached enamel immediately or 15 days later using different adhesive systems and laser application. METHODS: One hundred and forty enamel specimens were prepared from human molar teeth and bleached either with 16% carbamide peroxide (CP) or 30% CP according to the manufacturer's (Vivastyle/Vivadent) recommendations. After bleaching treatments specimens were divided into two groups according to the treatment time of the adhesive procedures: immediately or 15 days after the bleaching treatments. The four groups were then divided into five subgroups due to the surface treatments: using a two-step self-etching adhesive (AdheSe, Ivoclar Vivadent G, Schaan, Liechtenstein) or a two-step etch and rinse adhesive (Excite, Ivoclar Vivadent G, Schaan, Liechtenstein) and application of laser prior to adhesive procedures or not. After adhesive procedures nanohybrid composite resin cylinders of 4 mm x 2 mm (Tetric Evo Ceram/Vivadent) were bonded to the enamel surfaces. All specimens were subjected to shear bond strength test after thermocycling and 24h of storage in water. Data were analyzed statistically. RESULTS: Mann-Whitney U-test analysis showed no significant difference in the mean bond strength values of enamel bleached with either 16% CP or 30% CP (p>0.05). There was no difference between the groups bonded immediately or 15 days after bleaching (p>0.05). Application of the etch and rinse adhesive after 15 days showed the highest bond strength values, whereas self-etching adhesive and laser application showed the lowest values in both bleaching treatments. CONCLUSIONS: The results suggested that following the bleaching treatments, the use of etch and rinse adhesive system may provide higher bond strengths than self-etching adhesive and laser application.

Six-year clinical evaluation of packable composite restorations.

OBJECTIVE: For decades, resin composites have been used with increasing frequency as posterior restorative materials, because of the demand for aesthetic restoration. This study evaluated the six-year clinical performance of Filtek P60 (3M ESPE) packable composite restorations in combination with a one-bottle etch and rinse adhesive, Single Bond (3M ESPE), in Class II restorations. METHODS: A total of 47 restorations were placed in the Class II cavity preparations (27 premolars and 20 molars) of 33 patients (22 female/11 male; mean age 34) by the same operator. The restorations were evaluated by two examiners at baseline and 1, 2, 3 and 6 years according to the method developed by Ryge, which also is known as the United States Public Health Service (USPHS) criteria. The following characteristics were observed: marginal adaptation, anatomical form, surface texture, marginal discoloration, surface staining, post-operative sensitivity and secondary caries. The Chi-square and Wilcoxon signed rank test with Bonferroni adjustment were used for statistical analysis (p = 0.05). RESULTS: All the restorations received Alpha scores at baseline assessment, except for one restoration, which showed post-operative sensitivity. At the three-year recall examination, two patients, with a total of three restorations, were not included. From baseline to three years, only two of the 44 restorations changed from Alpha to Bravo, for numerous reasons. At the six-year recall, 44 restorations were available for examination. The majority of restorations exhibited Alpha or Bravo scores for the evaluated criteria. No significant differences were found for any of the clinical criteria (p > 0.05). Only two restorations needed to be repaired due to caries that began independently from the restorations. Three or four restorations showed slight surface staining and marginal discoloration. CONCLUSIONS: The clinical performance of the posterior composite restorations that were evaluated was acceptable after six years of service.

Shear bond strength of composite bonded to erbium:yttrium-aluminum-garnet laser-prepared dentin.

The purpose of this study was to evaluate the dentin bond strength to resin composite following erbium:yttrium-aluminum-garnet (Er:YAG) laser preparation using different adhesive systems. Seventy dentin specimens prepared from human molar teeth were randomly assigned to seven groups of ten. The first five groups were prepared with an Er:YAG laser 2940 nm at the manufacturer's recommended settings and (1) acid etched, and etch-and-rinse adhesive Excite was applied; (2) Excite was applied; (3) two-step self-etching adhesive AdheSE was applied; (4) laser etched (120 mJ/10 Hz), and Excite was applied; (5) laser etched, and AdheSE was applied. The last two groups were added as controls (prepared with a diamond bur): (6) acid etched, and Excite was applied; (7) AdheSE was applied. Nanohybrid composite cylinders 4 mm x 2 mm were bonded to the dentin surfaces. After the specimens had been stored in distilled water and had undergone thermocycling, the shear bond strength was tested and the data were analyzed statistically. The Duncan multiple comparison test showed that specimens prepared with a diamond bur and with acid and Excite applied showed the highest mean bond strength (13.01 +/- 2.09 MPa), followed by those prepared with Er:YAG and with AdheSE applied (11.5 +/- 3.59 MPa) and those prepared with a diamond bur and with AdheSE applied (10.75 +/- 1.95 MPa), but there were no significant differences among them (P > 0.05). Er:YAG-prepared specimens, with acid, Excite (3.28 +/- 0.95 MPa) and specimens that were laser etched and with AdheSE applied (3.37 +/- 0.63 MPa) showed the lowest mean values for bond strength (P < 0.05). The results suggested that dentin surfaces prepared with Er:YAG laser may provide comparable composite resin bond strengths depending on the adhesives used.

Shear bond strength of composite bonded to Er,Cr:YSGG laser-prepared dentin.

OBJECTIVE: The purpose of this in vitro study was to evaluate dentin bond strength to resin composite following high-speed rotary or Er,Cr:YSGG laser preparation using two different adhesive systems. MATERIALS AND METHODS: One hundred and forty dentin specimens were prepared from human molars. Seventy specimens were prepared with a high-speed diamond bur and 70 of the specimens were prepared with an Er,Cr:YSGG laser. Each group was subdivided into 7 groups of 10 teeth and etched with either 37% H3PO4, laser etched at two different power levels (1.25 W and 3 W), or not etched. Nano-hybrid composite resin cylinders 4 x 2 mm in size (Tetric EvoCeram, Vivadent) were bonded to the dentin surfaces with the application of an etch-and-rinse adhesive (Exite/Vivadent), or a self-etching adhesive (AdheSe/Vivadent). After storage in distilled water and thermocycling, a shear bond strength test was performed on all specimens and the data were statistically analyzed. RESULTS: ANOVA detected significant differences between the tested groups (p < 0.001). Duncan's multiple comparison test showed that Excite-applied specimens that were prepared with laser and laser etched (1.25 W or 3 W) had higher mean bond strengths. Both AdheSe- and Excite-applied specimens prepared with the diamond bur and laser etched (1.25 W) showed the lowest mean bond strength values (p < 0.05). CONCLUSION: The results suggest that dentin surfaces prepared with the Er,Cr:YSGG laser and etched with the laser (at either 1.25 or 3 W) may provide comparable or increased composite resin bond strengths, depending on the adhesive used.