Method and Materials: Thirty-two freshly extracted caries-free human third molars were used. A wide mesio-occlusal-distal (MOD) cavity was prepared in each third molar, with the occlusal dimension being approximately twothirds of the intercuspal dimension, and the cervical limit of one proximal box was stopped 1 mm below and the other 1 mm above the cementoenamel junction. The cavities were filled with a methacrylate-based nanohybrid composite (Grandio, VoCo) and a silorane-based microhybrid composite (Filtek Silorane, 3M ESPE). All samples were subjected to 1000 thermal cycles of 5°C/55°C in water with a 30-second dwell time and, after the procedure, the teeth were immersed in a 0.5% basic fuchsin dye at 23°C for 24 hours. Sectioned samples were examined under a stereomicroscope (Leica MZ12, Leica Microsystems), and microleakage scores were statistically analyzed using the Kruskal-Wallis and the Mann-Whitney U tests. Clinical RelevanceThis in vitro study showed that the Silorane-based microhybrid resin composite system had no microleakage for wide Class II MOD restorations with oblique and vertical layering techniques.

ObjectivesThis study aimed to evaluate the color stability of bulk-fill and nanohybrid resin-based composites polished with 3 different, multistep, aluminum-oxide impregnated finishing and polishing disks.Materials and MethodsDisk-shaped specimens (8 mm in diameter and 4 mm in thickness) were light-cured between two glass slabs using one nanohybid bulk-fill (Tetric EvoCeram, Ivoclar Vivadent), one micro-hybrid bulk-fill (Quixfil, Dentsply), and two nanohybrid incremental-fill (Filtek Ultimate, 3M ESPE; Herculite XRV Ultra, Kerr) resin-based composites, and aged by thermocycling (between 5 - 55℃, 3,000 cycles). Then, they were divided into subgroups according to the polishing procedure as SwissFlex (Coltène/Whaledent), Optidisc (Kerr), and Praxis TDV (TDV Dental) (n = 12 per subgroup). One surface of each specimen was left unpolished. All specimens were immersed in coffee solution at 37℃. The color differences (ΔE) were measured after 1 and 7 days of storage using a colorimeter based on CIE Lab system. The data were analyzed by univariate ANOVA, Mann-Whitney U test, and Friedmann tests (α = 0.05).ResultsUnivariate ANOVA detected significant interactions between polishing procedure and composite resin and polishing procedure and storage time (p < 0.05). Significant color changes were detected after 1 day storage in coffee solution (p < 0.05), except Quixfil/Optidisc which was color-stable after 7 days (p > 0.05). Polishing reduced the discoloration resistance of Tetric EvoCeram/SwissFlex, Tetric EvoCeram/Praxis TDV, Quixfil-SwissFlex, and all Herculite XRV Ultra groups after 7 days storage (p < 0.05).ConclusionsDiscoloration resistance of bulk-fill resin-based composites can be significantly affected by the polishing procedures.

BackgroundAlthough numerous studies have used digital intraoral imaging, only a few studies have used photo-optical methods for the diagnosis of caries. Moreover, several limitations exist in terms of observers (experience and specialty) and the caries lesion itself. Hence, the aims of this study were to evaluate the diagnostic capability of near-infrared light transillumination (NILT) and PSP-Bitewing radiographs and to compare the interobserver and intraobserver differences in addition to observers’ experience level to detect early interproximal caries lesions in vivo.MethodsA total of 52 untreated posterior teeth with and without varying degrees of early interproximal carious lesions were included. Bitewing radiographs using digital phosphor plates (PSP-Bitewing) and NILT were used to clarify the diagnosis. An oral and maxillofacial radiologist and a restorative dentistry consultant evaluated the images twice. A separate appointment for clinical validation and restoration was made. Kappa coefficients were calculated to assess both intraobserver and interobserver agreements for each evaluation method. Scores obtained from PSP-Bitewing and NILT were compared with the clinical validation via receiver operating characteristic (ROC) analysis.ResultsNo significant differences were found between PSP-Bitewing radiography and NILT for detecting early interproximal carious lesions with high average Az results. Both intraobserver and interobserver agreement values were relatively higher for NILT evaluation. The Az values increased at second evaluations for both caries detection methods.ConclusionsNILT examination has an appropriate sensitivity and diagnostic accuracy for detecting early interproximal caries lesions and can be considered as a method of choice for detecting caries without the use of ionizing radiation.

BackgroundThe 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 MethodsSeventy-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.ResultsThere 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.ConclusionsThe 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.

BackgroundAir-drying of etched and rinsed dentin surface may force the exposed collagen fibrils to collapse. Blot-drying is an alternative method to wipe the excess water from the dentin surface without compromising the monomer penetration. Contemporary total etch adhesives contain ethanol/water or acetone as solvent in which resin monomers are dissolved. Solvent type of the adhesive system has an important role in bonding to dentin. An adhesive containing tertiary butanol as an alternative solvent has been in the market. Purpose of this study is to determine the shear bond strengths of three total-etch adhesives with different solvents (acetone, ethanol or tertiary butanol) applied to air or blot dried moist dentin.MethodsSixty extracted non-carious human third molars were divided into three main groups according to solvent content of the adhesives [acetone based - One Step (OS, Bisco, IL, USA); ethanol/water based - Optibond Solo Plus (OB, Kerr, CA, USA); and tertiary butanol based - XP Bond (XP, Caulk/Dentsply, DE, USA)]. Each main group was divided into two groups according to drying methods (blot or air) (n = 10). Shear bond strengths (SBS) were measured. Data were analyzed by Student’s t test and Tukey HSD test (p < 0,05).ResultsXP showed highest SBS values in both drying methods applied (p < 0.05). Drying method did not influence the SBS in OS and OB (p > 0.05). XP-blot produced significantly higher SBS than XP-air (p < 0.05).ConclusionsTertiary butanol based adhesive showed higher bond strength values than ethanol or acetone based adhesives. Blot drying of dentin improved the bond strength values of tertiary butanol based adhesive. Further research is necessary to determine in vivo and in vitro performance of tertiary butanol based adhesives.