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Purpose: To evaluate the stress distribution along a premolar's root dentin, its post, and its post-luting agent when materials with different elastic moduli are used to fabricate one-piece post-and-cores in two different designs. Materials and Methods: Two 3D virtual models (for cylindrical and conical post designs) of a mandibular premolar restored with one-piece post-and-core restorations were obtained using a software. A total of eight post-and-core materials were tested: polyetheretherketone (PEEK), polyetherketoneketone (PEKK), glass fiber-reinforced polyetheretherketone (GFR-PEEK), carbon fiber-reinforced polyetheretherketone (CFR-PEEK), gold-palladium alloy (Au-Pd), titanium (Ti), zirconia (Zi), and chromium-nickel (Cr-Ni). Maximum principals stress (MPS) in the post, post-luting agent, and root dentin were determined. A load of 150 N was applied to the buccal cusp in the linguo-labial direction at an angle of 45 degrees oblique to the longitudinal axis of the crown. Results: The highest MPS value in post structure was observed with Cr-Ni material for both post designs. Similarly, the highest MPS value in the post-luting agent was observed for Cr-Ni, the material with the highest elastic modulus. However, in the root dentin, the highest value was observed in PEEK, the material with the lowest elastic modulus. Conclusions: Post material and design influenced the stress concentration in the post, post-luting agent, and root dentin. The stress at the root dentin was slightly higher for polymeric materials. Cylindrical post design revealed lower stresses than conical post design at root dentin for all post-and-core materials tested. [ABSTRACT FROM AUTHOR]

Purpose: The structural and compositional similarities between dentin and alveolar bone form the basis for utilizing dentin for bone regeneration. Various authors have recommended using treated mineralized, partially demineralized, or demineralized dentin grafts instead of xenografts because of their comparable clinical and radiographic results and lower costs. The current study therefore compared the effect of untreated mineralized dentin grafts (UMDGs) versus xenografts in vertical and horizontal augmentation around dental implants that were immediately placed in the mandibular anterior region. Materials and Methods: A total of 56 patients who required immediate dental implant placement in the mandibular anterior region were randomly allocated to group I (study), where ground dentin was washed with normal saline and placed around the dental implants, or group II (control), where a xenograft was used. The primary implant stability was measured at the time of implant placement. Secondary implant stability, plaque index (PI), bleeding index (BI), probing depth (PD), and keratinized mucosa width (KMW) were assessed at baseline (time of definitive abutment and provisional crown placement) and then at 3, 6, and 12 months. Pain and the number of analgesics consumed were assessed daily during the first postoperative week. Marginal bone loss (MBL) and radiodensity were assessed radiographically. Results: There were no significant differences between the groups in terms of postoperative pain, the number of analgesic tablets consumed, peri-implant mucositis, or peri-implantitis. Both groups showed comparable results for the PI, BI, and PD. Moreover, there was no statistical difference between the groups with regard to primary implant stability and secondary implant stability at baseline and 12 months. Group I showed significantly lower secondary implant stability after loading at 3 and 6 months and significantly greater bone loss and lower bone density before exposure. KMW and MBL after exposure were significantly higher in group I at all time points. Conclusions: Although UMDGs showed similar clinical results to xenografts, including primary and secondary implant stability, they had higher resorption rates than xenografts. Therefore, treatment of the dentin graft is required. Thus, the authors do not recommend using UMDGs. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of immediate dentin sealing (IDS) vs delayed dentin sealing (DDS) on the marginal gaps of machinable monolithic zirconia vs pressable lithium disilicate laminate veneers.Materials and Methods: A total of 40 maxillary lateral incisors were used and received butt-joint laminate veneer preparation. The samples were divided into two groups (n = 20 each) according to ceramic material: pressable lithium disilicate ceramic (PLD) was used in the first group, and machinable monolithic zirconia (MMZ) was used in the second. Each group was then divided into two subgroups according to the bonding protocol: IDS was employed in one, and DDS in the other (n = 10 each). The marginal gap widths were measured using digital microscopy and statistically analyzed.Results: The smallest marginal gaps were observed in MMZ-DDS (57.2 ± 8.4 μm), followed by PLD-DDS (62.4 ± 2.7 μm) and MMZ-IDS (63.5 ± 1.9 μm). The largest marginal gaps were observed in PLD-IDS (81.5 ± 6.3 μm). Two-way ANOVA revealed that the bonding technique (P < .001) and ceramic material (P < .001) both showed significant differences.Conclusions: MMZ produced better marginal accuracy than PLD. IDS seems to have a predisposition to significantly wider marginal gaps than DDS, but these gaps are within the clinically acceptable range. The marginal accuracy of ceramic veneers appears to be related to the bonding technique as well as the material of construction. [ABSTRACT FROM AUTHOR]

This study investigated the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser conditioning on dentin bond strength and nanoleakage of different universal and self-etch adhesives. A total of 84 intact human third molar teeth were cut at the dentin level, and half of them were laser conditioned. The specimens were divided into three groups; two different universal resins and one self-etch adhesive resin were applied and composite resin restorations were created. For the microtensile bond strength (pTBS) test, 20 microspecimens were prepared from the laser and control group of each adhesive (n = 20) and tested with a universal device. For nanoleakage observation, 10 specimens were prepared from each group (n = 10) and stored in silver nitrate solution, and then the amount of nanoleakage was analyzed by field emission scanning electron microscopy (FESEM). Data were analyzed with two-way ANOVA, Tukey's honestly significant difference, and chi-square tests. The mean dentin bond strength of all adhesives in the laser groups was found to be statistically significantly lower than those of the control groups (P < .05). No difference was found between the mean bond strength of the adhesives in the laser and control groups (P > .05). Higher nanoleakage was observed in all adhesives in the laser groups compared to the control groups (P < .05). Irradiation of the dentin surface with Er,Cr:YSGG could adversely affect the piTBS and nanoleakage, likely by affecting the structure of the hybrid layer. [ABSTRACT FROM AUTHOR]

Objective: This in vitro study evaluated the color differences when discolored tooth substrates were restored with CAD/CAM monolithic ceramics depending on ceramic type and thickness, and the try-in paste shade. Method and materials: Six ceramic types were tested: high-translucent lithium disilicate (LD-HT); medium-translucent lithium disilicate (LD-MT); low-translucent lithium disilicate (LD-LT); low-translucent leucite (LC-LT); feldspathic ceramic (FC); and BL1 low-translucent lithium disilicate, stained to A1 shade (LD-BL1-LT). The ceramics were tested in disk-shaped specimens with 0.5-, 1.0-, and 1.5-mm thickness (n = 10; N = 180; shade A1). The try-in pastes were tested to simulate luting materials and corresponded to colors A1 and Opaque White. Six substrates were used: A1 (reference), B2, B3, A3, C2, and C3. Color differences (ΔE00) and translucency parameter (TP00) were assessed with the CIEDE2000 formula. The results were compared with acceptability (1.77) and perceptibility (0.81) thresholds. Results: Ceramic type, thickness, and the try-in paste shade influenced the color differences. LD-LT and LC-LT ceramics and Opaque White try-in paste provided, in general, lower ΔE00 values. The most adequate ceramic thickness varied according to the substrate discoloration. With 1.0 mm of ceramic thickness, it was possible to obtain ΔE00 lower than the perceptibility threshold for substrates C2 and A3, and ΔE00 lower than the acceptability threshold for C3 and B3. ΔE00 lower than the acceptability threshold were obtained with 0.5 mm of ceramic thickness for B2, A3, and C2. Conclusion: The use of low-translucent glass-ceramics and Opaque White try-in paste are useful to reduce color differences. The most adequate ceramic thickness depends on the substrate discoloration. [ABSTRACT FROM AUTHOR]

This in vitro study investigated color stability of two photo-polymerized nano-filled and nano-hybrid composite resins in different polymerization modes immersed in different staining solutions before and after brushing. Disc-shaped specimens (n = 120) were prepared from two composite resins based on filler particle size: nano-filled (Filtek Z350, shade A1, 3M ESPE) and nano-hybrid (Spectra ST-HV, shade A1, Dentsply Sirona) composite resins (n = 60 per composite type). Specimens of each resin type were photopolymerized using the following polymerization modes: LED conventional, ramp, and pulse (n = 20 specimens per resin type and LED mode). After preparation, baseline color of the specimens was evaluated using a spectrophotometer (Easyshade V, VITA), and color change was evaluated using the CIE L*a*b* formula. Specimens were soaked in distilled water for 4 weeks in separate containers. The specimens from each polymerization-mode group were separated into two groups of 10 specimens; one group was stored in tea and the other group was stored in cola, each 1 hour daily for 4 weeks. After 4 weeks, the color was measured again. The specimens were brushed for 2 minutes under 200-g weight using an electronically powered toothbrush on the polymerized side of the specimen. The color was reevaluated immediately after brushing. Color-difference data (ΔE) between groups were analyzed by one-way analysis of variance for main comparison and by independent t test for color change after brushing. Nano-filled composite resin was more color-stable than nano-hybrid composite resin (P < .001), regardless of the staining media. For both composite resin types, the conventional polymerization method produced a more color-stable result (P < .0001). ΔE after brushing was reduced significantly (P < .0001). Both staining solutions have significant effects on color change, with tea staining more than cola (P < .0001). Nanofilled composite resin had greater color stability than nano-hybrid composite resin after immersion in staining solutions. Polymerization mode influences the color stability of both composite resin types. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the effect of toothbrush bristle stiffness and brushing force on the cleaning efficacy in vitro. Materials and Methods: Eighty bovine dentin samples were allocated to eight groups (n=10). Two custom-made toothbrushes of different bristle stiffness (soft and medium) were tested at four different brushing forces (1, 2, 3 and 4 N). Dentin samples were stained in black tea and brushed (60 strokes/min) for a total of 25 min in a brushing machine with an abrasive solution (RDA 67). Photographs were taken after 2 and 25 min of brushing time. Cleaning efficacy was measured planimetrically. Results: After 2 min of brushing, the soft-bristle toothbrush did not cause statistically significantly different cleaning efficacy at different brushing forces, while the medium-bristle toothbrush cleaned statistically significantly less efficaceously only at 1 N. Comparing the two different toothbrushes, higher cleaning efficacy was observed only at 1 N for the soft-bristle brush. At 25 min brushing time, the soft-bristle cleaned statistically significantly better at 4 N compared to 1 N and 2 N and at 3 N compared to 1 N. Using the medium-bristle, cleaning efficacy increased with increasing brushing force. After 25 min of brushing, no statistically significant difference was observed between the two different toothbrushes. Conclusion: Irrespective the brushing force, the use of a soft or medium toothbrush results in comparable cleaning efficacy. At 2 min brushing time, increasing the brushing force does not increase the cleaning efficacy. [ABSTRACT FROM AUTHOR]

Purpose: To assess the root surface roughness and substance loss induced by chemical and chemomechanical challenges on root surfaces pretreated with ultrasonic instrumentation, a hand scaler, or erythritol airflow. Materials and Methods: One hundred twenty (120) bovine dentin specimens were used in this study. Specimens were divided into eight groups and treated as follows: groups 1 and 2: polished with 2000- and 4000-grit carborundum papers but not instrumented ('untreated'); groups 3 and 4: hand scaler; groups 5 and 6: ultrasonic instrumentation; groups 7 and 8: erythritol airflow. Samples from groups 1, 3, 5, and 7 then underwent a chemical challenge (5 x 2 min HCl [pH 2.7]), whereas samples from groups 2, 4, 6, and 8 were subjected to a chemomechanical challenge (5 x 2 min HCl [pH 2.7] + 2 min brushing). Surface roughness and substance loss were measured profilometrically. Results: The least substance loss through chemomechanical challenge was noted after erythritol airflow treatment (4.65 ± 0.93 μm), followed by ultrasonic instrumentation (7.30 ± 1.42 μm) and the hand scaler (8.30 ± 1.38 μm); the last two (hand scaler and ultrasonic tip) did not differ statistically significantly. The highest roughness after chemomechanical challenge was observed on ultrasonically treated specimens (1.25 ± 0.85 μm), followed by hand-scaled specimens (0.24 ± 0.16 μm) and those subject to erythritol airflow (0.18 ± 0.09 μm); there was no statistically signficant difference between the latter two, but they both differed statistically significantly from the ultrasonically treated specimens. No statistically significant difference in substance loss through the chemical challenge was observed between specimens pretreated by the hand scaler (0.75 ± 0.15 μm), ultrasonic tip (0.65 ± 0.15 μm), and erythritol airflow (0.75 ± 0.15 μm). The chemical challenge smoothed the surfaces treated with the hand scaler, ultrasonic tip, and erythritol airflow. Conclusion: Dentin pretreatment with erythritol powder airflow resulted in a higher resistance to chemomechanical challenge than did dentin treated ultrasonically or with the hand scaler. [ABSTRACT FROM AUTHOR]

Purpose: To synthesise and characterise nanosilver sodium fluoride (NSSF) and assess the effect of applying this formulation in vitro on artificially demineralised root dentin lesions, compared with the application of silver diamine fluoride (SDF), sodium fluoride (NAF) or no treatment, in terms of mechanical, chemical and ultrastructural properties. Materials and Methods: NSSF was prepared using 0.5 wt% chitosan solution. On 40 extracted human molars, the buccal aspect of the cervical thirds of roots were prepared and divided into 4 groups of 10 each: control (no treatment), NSSF, SDF and NaF (n = 10). The specimens were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR), surface and cross-sectional microhardness and nano-indentation tests were performed to determine the mineral and carbonate content, microhardness, and nanohardness, respectively. Statistical analysis was performed to determine the differences between the different treatment groups for the set parameters using parametric and non-parametric tests. Tukey's and Dunnet's T3 post-hoc tests were further used for multiple comparisons between groups (α = 0.05). Results: The control group (no treatment) was found to have statistically significantly lower mean scores for surface and cross-sectional microhardness compared with all other test groups (NaF, NSSF and SDF) (p < 0.05). Spearman's rank correlation test showed statistically insignificant differences between the mineral-to-matrix ratio (M:M) and carbonate content of all groups (p < 0.05). Conclusions: Treatment of root lesions with NSSF yielded comparable results to SDF and NaF under in-vitro conditions. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of the supplementation of energy drinks with green tea extract on abrasive and erosive dentin wear. Materials and Methods: Six groups, each comprising 15 bovine dentin samples, were prepared, yielding a total of 90 samples. Erosion was performed by immersing the samples in Red Bull and Red Bull light with and without green tea extract. Tap water with and without green tea extract was used as the control groups. The samples were subjected to abrasive/erosive cycling for five days. The following cycling was performed daily: toothbrush abrasion (20 brushstrokes; 2.5 N); eight erosive cycles (2 min storage in the respective solutions); in between the erosive cycles, storage in artificial saliva (60 min) and again toothbrush abrasion (20 brushstrokes; 2.5 N). During the night, samples were again stored in artificial saliva. Abrasive/erosive dentin wear was measured using a stylus profilometer (μm, accuracy = 40 nm). The measured dentin loss results from the vertical position shift on the y-axis from base to final profile after the wear process in 2D. Pairwise comparisons between the groups were carried out using Wilcoxon signed-rank test. Results: The following dentin wear (median [IQR]) was measured: Red Bull: 1.9 μm (0.5); Red Bull Light: 1.3 μm (0.3); Red Bull with green tea extract: 0.8 μm (0.3); Red Bull Light with green tea extract: 0.3 μm (0.5); Tap water with green tea extract: -0.2 μm (0.7); Tap water: -1.0 μm (1.2). The comparison of all tested groups to each other proved to be statistically significant (p < 0.05). Conclusion: The supplementation of energy drinks with green tea extract provide a protective effect against erosive/ abrasive wear in vitro. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the absolute wear caused by toothpastes with highly discrepant REA (Relative Enamel Abrasivity) and RDA (Relative Dentin Abrasivity) values on both enamel and dentin: Candida Peppermint (CP; REA: 1; RDA: 42), Colgate Total Original (CTO; REA: 4; RDA: 100), Signal White System (SWS; REA: 8; RDA: 143), and Candida White Diamond (CWD; REA 244; RDA: 12). Materials and Methods: Eighty (80) bovine enamel samples and 80 dentin samples were divided into four groups each (n = 20) and investigated after a 6-h brushing procedure (21,600 cycles, 60 cycles/min, load of 2.5 N) with the four toothpastes. The abrasive enamel and dentin wear were registered using a contact profilometer. The median and interquartile range (IQR) of the abrasive enamel and dentin wear were calculated for each group. Pairwise comparisons were conducted using the Wilcoxon signed-rank exact test, and the p-value was adjusted according to Holm (statistical significance set at 0.05). Results: CWD led to the highest abrasive enamel wear (9.86 μm [5.77]). CTO caused the highest abrasive dentin wear (166.70 μm [69.90]), being statistically significantly higher than the wear for CP (54.20 μm [24.00]) and CWD (17.00 μm [7.80]) (p = 0.00001). The abrasive dentin wear for CWD was statistically significantly lower in comparison to all other groups (p = 0.00001). Conclusion: Toothpastes with highly discrepant REA and RDA values presented statistically significantly different absolute wear on enamel and dentin. REA and RDA values should both be declared for every toothpaste. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of carbodiimide (EDC) and chitosan (CHI) on the enzymatic activity (EA) and bond strength (BS) of different composite cements to root dentin. Materials and Methods: Ninety (90) maxillary canines were sectioned, standardizing the length of the roots. The roots were endodontically treated, prepared, divided into 3 groups according to dentin treatment (distilled water [DW], CHI 0.2 wt%, or EDC 0.5M), and further subdivided into 3 subgroups according to composite cement (RelyX ARC [3M Oral Care], Panavia F 2.0 [Kuraray Noritaki], or RelyX U200 [3M Oral Care]). Of the slices obtained by sectioning, the most cervical of each third were subjected to a push-out test and the most apical were subjected to in-situ zymography. Half of the slices were analyzed immediately, and the other half after 6 months. The results were analyzed with ANOVA or the chi-squared test. Results: RelyX ARC showed higher BS associated with CHI, while RelyX U200 showed higher BS associated with EDC (p = 0.044). For Panavia F 2.0, the treatment did not influence BS (p > 0.05). For the cervical and middle thirds, no differences were observed between the cements, while the apical third revealed higher BS for RelyX U200 (p < 0.001). The highest percentage of adhesive-to-dentin failures was observed for Panavia F 2.0. EDC showed the lowest percentage of adhesive-to-dentin failures. According to zymographic analysis, DW and CHI showed greater fluorescence for RelyX ARC, while EDC exhibited the lowest fluorescence of all cements (p > 0.05). Conclusion: The different mechanisms of action of solutions for pre-treatment of intraradicular dentin yielded different results depending on the adhesive used. EDC resulted in higher bond strength and higher enzyme inhibition for RelyX U200, while the treatment with chitosan resulted in higher bond strength and lower enzymatic activity for RelyX ARC. Although EDC and chitosan treatments did not influence the bond strength for Panavia F 2.0, both resulted in higher enzyme inhibition for this composite cement. [ABSTRACT FROM AUTHOR]

Purpose: This study compared a 2%-CHX dentin pre-treatment with three CHX adhesives (experimentally admixed 0.1% CHX in primer or bonding agent, or industrially added 0.2% CHX in universal adhesive) by evaluating dentin bond strengths after biological loading in a fully automated artificial mouth model. Materials and Methods: The occlusal dentin of 50 freshly extracted human third molars was exposed, and the teeth were randomly assigned to 5 groups according to the adhesive protocol (n = 10): 1. control, Scotchbond Multipurpose (3M Oral Care; CTRL); 2. 2% CHX dentin pre-treatment (DENT); 3. 0.1% CHX experimentally admixed into the primer (PRIM); 4. 0.1% CHX experimentally admixed into the bonding agent (BOND); 5. Peak Universal Bond containing 0.2% CHX (Ultradent; PEAK). The teeth were restored with composite resin. Microtensile bond strength testing (bonding area 0.46 mm2 ± 0.04 mm², crosshead speed 1 mm/min) was performed after 24-h storage in distilled water (baseline) or after 2-day biological loading with S. mutans (demineralization 1 h / remineralization 5 h). The mode of fracture was recorded and exemplary sticks were evaluated under SEM. Results: CTRL exhibited significantly higher μTBS at baseline in comparison to PRIM (p = 0.000), BOND (p = 0.002), and PEAK (p = 0.000). After undergoing the caries model, CTRL demonstrated significantly lower μTBS compared to DENT (p = 0.000), PRIM (p = 0.008), and PEAK (p = 0.000). The same behavior was observed for BOND vs DENT (p = 0.000), PRIM (p = 0.003), and PEAK (p = 0.001). After biological loading, DENT (p = 0.041), PRIM (p = 0.000), and BOND (p = 0.000) exhibited significantly fewer adhesive fractures than CTRL. Conclusions: CHX addition to the primer protects dentin bond strength from declining after biological loading. Thus, it may offer some clinical advantage in terms of secondary caries inhibition around composite restorations. However, since loss of adhesion at baseline was less when 2% CHX was used as a dentin pre-treatment, it can be suggested as a safer option. so that bonding is not undermined by potential chemical interactions from CHX with the adhesives. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical outcomes of autogenous and allogeneic demineralized dentin matrices loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2; auto- and allo-DDM/rhBMP-2) by measuring the buccal marginal bone resorption around dental implants. Materials and Methods: This retrospective study included patients who underwent dental implant placement with auto-DDM/rhBMP-2 as the control group and allo-DDM/rhBMP-2 as the experimental group. The primary outcome was buccal marginal bone resorption on CBCT. The resorption was calculated during T0 (from surgery to prosthetic loading), T1 (during the first year after loading), and T2 (during the second year after loading). The secondary outcome was the histologic analysis of five specimens of each group, obtained during the prosthetic procedure. Results: Among the 103 implants, 61 and 42 implants were placed with auto- and allo-DDM/rhBMP-2 matrices, respectively. The resorptions of all periods were similar between the groups (T0: 0.65 ± 0.71 and 0.67 ± 0.81 mm, T1: 0.55 ± 0.60 and 0.59 ± 0.81 mm, and T2: 0.29 ± 0.45 and 0.20 ± 0.30 mm with auto- and allo-DDM/rhBMP-2, respectively). The histologic and histomorphometric analysis revealed similar osteoinductive aspects and proportions of new bone between the groups. Conclusion: Allo-DDM/rhBMP-2 showed comparable outcomes in terms of buccal marginal bone resorption to auto-DDM/rhBMP-2 during the second year after loading. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this in vitro study was to evaluate the influence of the ceramic thickness, cement shade, and airborne-particle abrasion of the titanium on the final color of titanium base cemented lithium disilicate glass-ceramic restorations. Method and materials: In total, 144 lithium disilicate glass-ceramic disks of three thicknesses (0.5, 1.0, and 1.5 mm) were cemented to airborne-particle-abraded and non-airborne-particle-abraded titanium disks with six adhesive resin cements. The color measurements were performed with a clinical spectrophotometer. The mean and standard deviation of evaluated ΔE values were calculated. A three-way analysis of variance (ANOVA) was used for analyzing the data. Statistical analyses were computed with a significance level of α = .05 using a statistical software program (Minitab 17, Minitab). Results: The 0.5- and 1-mm-thick ceramic specimens cemented with Panavia V5 Opaque showed the lowest ΔE values when cemented on both non-airborne-particle-abraded (5.62 ± 1.66, 3.15 ± 1.28) and airborne-particle-abraded (5.55 ± 0.86, 3.16 ± 0.49) surfaces, while the highest values were seen in the groups cemented with RelyX U200 A2 (29.22 ± 0.83, 17.23 ± 0.45) and Panavia V5 A2 (29.94 ± 1.17, 16.71 ± 0.44) on airborne-particle-abraded surfaces. For the 1.5-mm-thick ceramics, the lowest ΔE values were seen when Multilink MO 0 cement was used on non-airborne-particle-abraded surfaces (1.56 ± 0.29) and when Panavia V5 Opaque was used on airborne-particle-abraded surfaces (1.56 ± 0.66). The highest values were seen when RelyX U200 A2 (9.77 ± 1.13), PA2 (9.24 ± 0.25), and Multilink HO 0 (9.19 ± 1.33) were used on airborne-particle-abraded surfaces, and when Multilink HO 0 (9.61 ± 1.70) was used on non-airborne-particle-abraded surfaces. The 1-mm-thick ceramics cemented with Multilink HO 0 showed higher ΔE values (12.05 ± 1.99) for airborne-particle-abraded and non-airborne-particle-abraded (12.58 ± 1.06) than thinner (0.5 mm) or thicker (1.5 mm) ceramics. Conclusion: Thinnest ceramic superstructures resulted in the highest ΔE values. Cements that mask the underlying color reflect their own shade under thin superstructures. Airborne-particle abrasion of titanium surfaces increases the grayish reflectance if cement shade does not have the color masking ability. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the survival and success rate of and the incidence of complications affecting implants inserted and immediately loaded in sites where an impacted tooth was present in the maxilla. Materials and methods: A total of 10 patients were treated and 14 implants were inserted, 4 in healed sites and 10 in extraction sites. The implant site preparation started in the crestal bone and continued in the enamel and dentine of the impacted tooth. The radiographic depth of implant penetration into the impacted tooth, peri-implant soft tissue and hard tissue condition at the 1-year follow-up and the last follow-up appointment, marginal bone loss at the 1-year follow-up and the last follow-up appointment, and the final aesthetic result were evaluated. Results: The implants healed uneventfully with an adequate hard and soft tissue response and no adverse clinical or radiographic signs or symptoms. They were in function for a minimum of 3 and a maximum of 11 years (mean 7.2 years). Conclusion: Although further studies with a larger sample size are required to validate this unconventional approach, it can be considered a valuable clinical option to replace teeth in an area of impaction. [ABSTRACT FROM AUTHOR]

The dentine sialophosphoprotein (DSPP) gene is the only identified causative gene for dentinogenesis imperfecta type 2 (DGI-II), dentinogenesis imperfecta type 3 (DGI-III) and dentine dysplasia type 2 (DD-II). These three disorders may have similar molecular mechanisms involved in bridging the DSPP mutations and the resulting abnormal dentine mineralisation. The DSPP encoding proteins DSP (dentine sialoprotein) and DPP (dentine phosphoprotein) are positive regulators of dentine formation and perform a function during dentinogenesis. The present review focused on the recent findings and viewpoints regarding the relationship between DSPP and dentinogenesis as well as mineralisation from multiple perspectives, involving studies relating to spatial structure and tissue localisation of DSPP, DSP and DPP, the biochemical characteristics and biological function of these molecules, and the causative role of the proteins in phenotypes of the knockout mouse model and in hereditary dentine defects. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this in vitro study was to compare the shear bond strength of a CAD/CAM resin-based composite restoration material with a lithium-disilicate-ceramic restoration material on human dentin. In addition, the influence of the chosen adhesive system should be investigated. Method and materials: Thirty cylindrical specimens each were fabricated from the composite resin-based material Grandio Blocs (GB) and the ceramic IPS e.max CAD (IEM). In each case, 15 specimens were bonded to human dentin samples using the adhesive system recommended and provided by the manufacturer. For 15 additional specimens, the adhesive systems were interchanged. After water storage (4 weeks) and thermocycling (5,000 cycles between 5°C and 55°C), the shear bond strength, the fracture modes, and the Adhesive Remnant Index (ARI) were determined. All data were statistically evaluated (Kruskal-Wallis test; P < .05). Results: The shear bond strength of IEM in combination with the manufacturer's recommended adhesive system was statistically significantly higher than in those of all other groups (P < .05), resulting in 39.24 ± 7.73 N/mm2. For IEM, adhesive fracture mode was the only mode found, while adhesive and mixed fracture modes occurred in both GB groups. Significantly more adhesive/restoration material remnants (ARI) remained on the dentin surfaces in both GB groups (P < .05). Conclusion: For IEM the adhesive system recommended by the manufacturer should be used. For the GB samples, the choice of adhesive system had no influence on the shear bond strength. With GB, fracture may occur partly within the material under heavy load. [ABSTRACT FROM AUTHOR]

Some cases of asymptomatic traumatic cyst can be sizable; therefore, they require complete curettage and grafting with bone substitution materials. This case report presents a sizeable traumatic mandibular cyst in a young man treated by surgical exploration and filled with autologous dentin graft (ADG) prepared from an extracted impacted tooth 48 (FDI tooth-numbering system) and advanced platelet-rich fibrin (A-PRF). Initially, an A-PRF membrane was used to cover the apices of teeth 42 and 43, which were protruding into the defect to protect their periapical structures. Then, a grafting strategy was introduced to achieve two fronts of bone formation: one by stimulation of bone outgrowth from the periphery due to A-PRF cellular activity, and a second by bone deposition directly on dentin particles in the center of the defect. On CBCT scans performed 7 months postoperatively, arrays of trabeculae that were extending from bone boundaries of the cyst defect were merged with more condensed bone deposited on ADG residuals in the center, thus filling the defect. It was found that autologous dentin combined with cellular A-PRF activity is a powerful tool to restore even sizable bone defects in a relatively short time frame with adequate bone remodeling. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of autogenous particulate dentin as a bone substitute to maintain dimensional volume in human socket preservation procedures. Materials and Methods: Particulate dentin was used in socket site preservation procedures. The extracted natural tooth was ground to particles 250 to 1,200 µm in size to fill the socket site. At 6 months, during the implant placement stage, hard tissue biopsy specimens were harvested by a 2.5-mm cylindrical trephine bur for the histologic analysis. Histomorphometry was carried out with ImageJ software to calculate direct bone to grafted dentin particles contact, newly formed bone, and particulate dentin area fractions. Results: Fifteen patients went through the socket preservation procedure using particulate dentin as the grafted bone substitute. De novo bone formation filled the entire grafted area. Newly formed bone was observed throughout the entire grafted area, particularly around the grafted dentin particles. The majority of particles were surrounded by direct contact with newly formed osseous tissue enriched by osteocytes. Newly formed bone ankylosed to particulate dentin and became a solid matrix preserving the ridge dimension. Histomorphometric measurements showed that the new bone formation area fraction was on average 38.4% ± 16.5%, while the residual particulate dentin showed an average of 29.9% ± 14.4%, and 31.7% ± 14.2% was captured by the connective tissue component. Particulate dentin was in direct contact with newly formed bone at an average rate of 69.1% ± 22.8%. Conclusion: Particulate dentin showed complete biocompatibility and high osteoconduction. Thus, it can be used as an appropriate grafting biomaterial to maintain socket site volume dimensionally for subsequent implant placement procedures. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of dimethyl sulfoxide (DMSO) solutions used as dentin pretreatments on microtensile bond strength (µTBS), as well as the dentin/restoration interface micromorphology of a universal adhesive in etch-and-rinse or self-etch mode. Materials and Methods: Eighty blocks of dentin were submitted to acid conditioning with 35% phosphoric acid (etch-and-rinse), or not (self-etch), and distributed among the treatments (n = 10): CON: Scotchbond Universal/3M Oral Care; DMSO: pretreatment with DMSO; DMSO/water: pretreatment with DMSO in water (1:1); DMSO/ethanol: pretreatment with DMSO in ethanol (1:1). Microtensile bond strength and failure tests were performed after 24-h and 6-month storage. The tooth-restoration interface was evaluated using scanning electron microscopy to assess the hybrid layer formed. Results: The interaction between treatments, storage time, and etching modes was not significant for µTBS (p = 0.2469). The DMSO, DMSO/water and DMSO/ethanol pretreatments did not affect µTBS values at either time point (p = 0.8732). Aging decreased µTBS over time only for the etch-and-rinse strategy, although the groups presented higher microtensile bond strengths in etch-and-rinse mode than in self-etch mode at both time points (p < 0.0001). The micromorphological images of the interface showed that different DMSO pretreatment solutions did not impair hybrid layer formation. Conclusion: The use of dentin pretreatments containing DMSO did not improve the bonding or the micromorphology of a universal adhesive in etch-and-rinse or self-etch modes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate push-out bond strength (PBS) and interfacial nanoleakage (NL) of adhesively luted fiber posts using different composite cements and polymerization protocols. Material and Methods: 100 premolars were endodontically treated and assigned to the following groups (n=10): RelyX Universal light-cure (3M Oral Care); RelyX Universal self-cure (3M Oral Care); Maxcem Elite Chroma light-cure (Kerr); Maxcem Elite Chroma self-cure (Kerr); Calibra Universal light-cure (Dentsply Sirona); Calibra Universal selfcure (Dentsply Sirona); Multilink Automix light cure (Ivoclar Vivadent); Multilink Automix self-cure (Ivoclar Vivadent); Luxacore Z Dual light-cure (DMG); Luxacore Z Dual self-cure (DMG). Half of the teeth from each group were subjected to the PBS test after 24 h (T0), while the other half was tested after 12 months (T12) of artificial saliva aging. An additional 4 teeth per group were prepared for NL expression. PBS values were analyzed using multivariate ANOVA and Tukey's post-hoc test. NL scores were analyzed using chi-squared tests (a = 0.05). Results: Statistical analysis revealed that the variables "cement" and "aging" significantly influenced PBS (p < 0.05), but not "polymerization" and "root region" (p > 0.05). Significantly lower PBS values (p < 0.05) were detected for the Calibra Universal groups compared to other cements, while the RelyX Universal groups performed equally well (p > 0.05) or better than other cements (p < 0.05). At T12, PBS values increased in the majority of groups, irrespective of root region (p < 0.05). Differences in NL expression were present at T0, and in general, the aging process increased marginal infiltration. Conclusion: Aging and choice of composite cement influenced PBS, while root region and polymerization protocol seemed to have no influence on posts' resistance to dislodgment. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of C-factor on the bond strength of universal adhesives to floor and wall dentin in class-I composite restorations using a bulk-fill composite. Materials and Methods: 108 non-carious humans third molars were randomly divided into four groups as follows: flat wall, flat floor, cavity wall, and cavity floor (n = 36). Then, each group was subdivided into three subgroups according to the type of adhesive used: Single Bond Universal, G-premio Bond (both universal adhesives), or Adper Single Bond 2 (an etch-and-rinse adhesive). After the bonding procedure, X-tra fill resin composite was applied in bulk to build up the flat surfaces or fill the cavities. Then the teeth were sectioned into 1-mm2 sticks and microtensile bond strength (µTBS) was measured using a universal testing machine. µTBS (MPa) was analyzed by one-way, two-way, and three-way ANOVA using SPSS Version 23 (a = 0.05). Results: Interactions between adhesives and bonding surfaces, as well as C-factor and bonding surfaces showed statistically significant differences, but the interaction between the C-factor and type of adhesive was not statistically significant. The comparison of bonded surfaces including the flat wall and the flat floor in Adper Single Bond 2 was statistically significant (p < 0.05), except for the cavity wall and cavity floor. Conclusion: Regardless of the type of adhesives, the C-factor reduced the µTBS of the composite resin to dentin. Adper Single Bond 2 mediated higher µTBS than did the universal adhesives G-premio Bond and Single Bond Universal. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate through a systematic review and meta-analysis the bonding performance of adhesive materials to silver diamine fluoride (SDF)-treated dentin. Materials and Methods: Studies located in PubMed, Web of Science, LILACS, and Scopus up to September 2020, which compared the bond strength of adhesives (AD) or glass-ionomer cement (GIC) to SDF-treated and untreated (control) dentin were included. Mean differences were estimated separately by material and dentin condition (sound or caries-affected), with a random-effects model, at a 5% significance level. Results: Twenty-two studies, including 11 new studies not included in our previous systematic review, met the eligibility criteria, and 21 studies were considered in the meta-analyses. SDF dentin pretreatment did not influence the bonding of GIC (Z = 0.53; p = 0.60), independent of dentin condition. SDF treatment significantly impaired the bonding of AD (Z = 2.43; p = 0.01). A rinsing step after SDF eliminated this effect in sound dentin (Z = 1.82; p = 0.07) and increased the bond strength to caries-affected dentin (Z = 2.14; p = 0.03). Conclusion: SDF pretreatment does not influence the bond strength of GIC. A rinsing step after SDF application can improve the bond strength of AD to caries-affected dentin. [ABSTRACT FROM AUTHOR]

The use of autologous dentin as an alternative to conventional regeneration biomaterials has become increasingly common, having been described in the literature since the 1960s, demonstrating its efficacy. Certain components that form the teeth, such as type 2 bone morphogenetic proteins (BMP-2), type I collagen, and hydroxyapatite, have been widely proven to be effective and are essential materials in the regeneration of alveolar bone. It is known that regenerated bone is histologically indistinguishable from native bone, and therefore, conditions and materials that allow for adequate replacement by host bone and that do not persist over time are key. With the present case report, encouraging advances in the use of autologous dentin as a graft material are demonstrated. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of four commercial silver diamine fluoride (SDF) agents on the chemical composition and microstructural properties of dentin, and its relation to the bond strength of two adhesives. Materials and Methods: Ninety human molars were randomly divided into sound dentin (negative control), demineralized dentin (positive control), and four experimental groups (n = 15) according to the SDF treatments (Cariestop [Biodinamica Quimica y Farmaceutica], RivaStar 1 [SDI], RivaStar 2 [SDI], and Saforide [Tokyo Seiyaku Kasei]). ATR-FTIR, x-ray diffraction, and SEM techniques were employed to characterize the compositional, crystalline, and microstructural properties of the samples. The microtensile bond strength test evaluated the bonding performance of two adhesives in demineralized dentin treated with SDF agents. Results: Regarding the chemical composition, all SDF-treated groups showed a significantly higher phosphate:organic matrix ratio than the demineralized dentin group (p < 0.05). The XRD analyses revealed that the crystallite size for hydroxyapatite crystals increased on the surface areas (deep, medium, and superficial dentin) for all experimental groups compared to demineralized dentin (p < 0.05). SEM images showed that the behavior of the agents used differs on each surface treated. Bond strength values were adversely affected with both adhesive systems in the four experimental groups (p < 0.05). Conclusions: The application of SDF agents resulted in the formation of different crystalline phases of silver salts and the increase of mineralization of the pretreated demineralized dentin. However, SDF application showed a negative effect on the bond strength of the adhesives. [ABSTRACT FROM AUTHOR]

Managing teeth with hypoplasia stains or discoloration using composite resin materials is challenging. When appraising hypoplasia stains, the substrate color and thickness of the material must be considered. The non-Vita shading system has a reduced number of layers, primarily dentin and enamel, which is known as the natural layering concept. The incremental approach of this system allows the masking of substrates with color differences and the reproduction of the optical characteristics of chromaticity, trans'uceicy or opacity as well as the value (luminosity). The present study demonstrates and discusses the color sequence for the natural reproduction of tooth structures using an alternative composite resin system from the classical Vita scale. (Int J Esthet Dent 2023;18:406-414) [ABSTRACT FROM AUTHOR]

Dentine is a major component of teeth and is responsible for many of their functions, such as mastication and neural sensation/transduction. Over the past decades, numerous studies have focused on dentine development and regeneration using a variety of research models, including in vivo, ex vivo and in vitro models. In vivo animal models play a crucial role in the exploration of biochemical factors that are involved in dentine development, whereas ex vivo and in vitro models contribute mainly to the identification of biophysical factors in dentine regeneration, of which mechanical force is most critical. In the present review, research models involved in studies related to dentine development and regeneration were screened from publications released in recent years and summarised comprehensively, particularly in vivo animal models including prokaryotic microinjection, Cre/LoxP, CRISPR/Cas9, ZFN and TALEN, and scaffold-based in vitro and ex vivo models. The latter were further divided by the interactive forces. Summarising these research models will not only benefit the development of future dentine-related studies but also provide hints regarding the evolution of novel dentine regeneration strategies. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the microtensile bond strength (μTBS) of a one-step self-etch adhesive (1-SEA) to dentin and its interfacial nanomechanical properties after 8 years of water storage. Materials and Methods: Flat coronal dentin surfaces of extracted human third molars were bonded with a 1-SEA (Clearfil S3 Bond Plus, CS3+) and built up with a hybrid resin composite (Clearfil AP-X). After storage in water for 24 h or 8 years, non-trimmed stick-shaped specimens were fabricated from the central part of each bonded tooth and subjected to the μTBS test at a crosshead speed of 1.0 mm/min. Failure modes and the morphology of debonded interfaces were analyzed using a scanning electron microscope (SEM). In addition, the elastic modulus (E) and hardness (H) of the adhesive layer and the resin composite were determined by an instrumented nanoindentation test. The acquired μTBS, E, and H data were statistically analyzed using t-tests to examine the effect of storage time (α = 0.05). Results: The 8-year μTBS was slightly lower than that after 24 h, but the difference was not significant (p = 0.123). The SEM observation of debonded surfaces after 8 years revealed extrusions and lacunas. E and H of the adhesive layer and the resin composite significantly decreased over the 8-year water storage (p < 0.001). Conclusions: Although 8 years of water storage did not decrease the μTBS of CS3+ significantly, the observed failure mode patterns and significantly decreased nanomechanical properties indicated resin degradation of the adhesive and the resin composite. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the changes in the dentin bond strengths of universal adhesives during the early phase and evaluate the effect of a double-layer adhesive application on the performance of the dentin bond. Materials and Methods: Three universal adhesives and a two-step self-etch adhesive were employed to ascertain the shear bond strengths (SBS) of specimens to bovine dentin with the use of the etch-and-rinse or self-etch mode. The specimens were further divided into two groups based on adhesive application in a single or a double layer. The bonded specimens were stored in distilled water at 37°C for 5 min or 1, 6, 12, or 24 h prior to SBS measurement and the adhesives’ Knoop hardness number (KHN). Results: All the adhesives showed increased SBS with prolonged storage periods regardless of the adhesive layer (single or double) or etching mode. Most universal adhesives in the double adhesive layer groups showed significantly higher SBS than single adhesive layer groups for the same storage period. All the adhesives also showed increased KHN with increased storage period. Conclusion: The SBS and KHN values of the adhesives increased with increasing storage duration over a 24-h period. Double adhesive layer application mediated increased dentin bond strength in the early phase. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluated dentin bond strength, failure mode, interface morphology, adhesive infiltration into dentin, and marginal adaptation of bulk-fill composites used with different adhesives. Materials and Methods: Third molars received occlusal class I cavities (4 mm x 4 mm x 4 mm) that were bulk-filled with Admira Fusion x-tra (Voco) or SonicFill 2 (Kerr) using four adhesives (Scotchbond Multipurpose, 3M Oral Care; Clearfil SE Bond, Kuraray Noritake; OptiBond All-In-One, Kerr; Futurabond U, Voco). Scotchbond was used with acidetching, while the remaining adhesives were applied in self-etch mode. Sixty-four teeth were selected for the microtensile bond strength test (n = 8). Failure modes were analyzed with scanning electron microscopy (SEM). Interface morphology and adhesive infiltration (n = 3) were investigated using confocal laser scanning microscopy (CLSM). Marginal adaptation (n = 3) was also evaluated using SEM. Bond strength, failure mode, and adhesive infiltration data were analyzed for distribution and homocedasticity, followed by appropriate statistical analyses (α= 0.05). Results: Regarding bond strength, no differences were found among adhesives for SonicFill; Clearfil showed a significantly lower mean value than did Scotchbond (p ≤ 0.05) for Admira; the two composites did not differ. Adhesive and mixed failures were observed for all groups. Scotchbond led to thicker hybrid layers with deeper adhesive infiltration as opposed to Futurabond. The groups Admira+Futurabond, SonicFill+Clearfil, and SonicFill+Futurabond presented the highest marginal discontinuity. Conclusion: The tested bulk-fill composites did not affect dentin bonding. Scotchbond and Clearfil seem to be reliable for bonding SonicFill 2 to dentin. The performance of Futurabond was questionable, given its poor-quality interface and higher percentages of marginal gaps. [ABSTRACT FROM AUTHOR]

Purpose: The effect of surface moisture on bur-cut dentin on the microtensile bond strength (µTBS) of universal adhesives with various contents of 2-hydroxyethyl methacrylate (HEMA) and methacrylamide monomers was evaluated. Materials and Methods: Flat mid-coronal dentin surfaces of human molars were exposed, and a standardized smear layer was prepared using a fine-grit diamond bur. The surfaces were either left wet or air dried for 10 s before bonding with Clearfil Universal Bond Quick (UBQ), experimental UBQ without an amide monomer (UBQexp), Scotchbond Universal (SBU), Prime&Bond Universal (PBU), or BeautiBond Universal (BBU). The specimens were built up with resin composite, sectioned into sticks and subjected to the µTBS test after 24 h or 10,000 thermal cycles. The µTBS data were analyzed using three-way ANOVA followed by pairwise comparisons with Bonferroni's correction (a = 0.05). Results: The level of dentin moisture did not significantly affect µTBS of UBQ and BBU (p > 0.05). HEMA-containing UBQ, UBQexp, and SBU exhibited higher µTBS to dry dentin, while HEMA-free PBU and BBU showed higher µTBS to wet dentin. Thermocycling significantly decreased the µTBS of UBQexp (p < 0.01) and BBU (p < 0.001) irrespective of dentin moisture level, while SBU was significantly affected only on dry dentin (p < 0.001). Thermocycling had no significant effect on UBQ and PBU containing methacrylamide monomers (p > 0.05). Conclusion: Dry surfaces enabled obtaining optimal bonding for HEMA-containing adhesives to bur-cut dentin, while wet surfaces enabled optimal bonding for HEMA-free adhesives. Methacrylamide monomers could contribute to the improvement of the initial and long-term bonding performance of universal adhesives to bur-cut dentin. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluated whether active application of self-etching adhesives would influence their microtensile bond strength (µTBS) to dentin cut with burs of different grit sizes. Materials and Methods: Eighty-four human premolars were divided into 12 groups according to 1) two dentin surface preparations with either superfine- or regular-grit diamond burs; 2) three adhesives - Clearfil SE Bond 2 (SE2), Scotchbond Universal (SBU, 3M Oral Care) and G-Premio Bond (GPB, GC); and 3) two application modes of each adhesive (active or passive). Six bonded teeth per group were sectioned into sticks for µTBS testing. Statistical analyses were performed using 3-way ANOVA followed by Duncan's test (p < 0.05). Additional teeth were prepared to observe the interaction between the dentin smear layer obtained from each bur with adhesives under different application modes using transmission electron microscopy (TEM). Results: Active application significantly increased the dentin bond strength of SE2, irrespective of the kind of bur used (p < 0.05). The highest bond strength of SBU was observed when bonded to superfine-grit diamond bur-cut dentin with the active application. There was, however, no influence of the tested factors on GPB group (p > 0.05). TEM observation showed that active application promoted dentin smear layer dissolution in all adhesive groups. Conclusions: Bond strengths of self-etching adhesives to dentin are influenced by bur-cut smear layers and mainly by application mode of adhesive materials. Active application improves µTBS of self-etching adhesives by enhancing smear layer modification and resin penetration into bur-cut dentin. [ABSTRACT FROM AUTHOR]

Different kinds of interactions between the restorative material and mineralized dental tissues result in secondary caries around dental composites. Of these, the mechanical interactions have to be carefully investigated. Due to the elastic mismatch between dental tissues and the composite restoration, complex stresses and strains develop at their interface. This complex mechanical environment disturbs the demineralization-remineralization equilibrium of dental hard tissues. The fluid flow both over and within enamel and dentin, associated with their complex ultrastructure and mechanical behavior, is a key factor. It is known that external mechanical loading can indirectly promote the dissolution of enamel and dentin through a pumping action of cariogenic fluids in and out of microgaps at the interface between mineralized tissues and composite. Mechanical loading can also directly influence the physicochemical behavior of dental hard tissues by inducing complex strain and stress fields on the crystal scale. It is important to consider both the direct and indirect paths by which mechanical loading can influence the apatite dissolution kinetics. Therefore, a systematic approach should be used to investigate the mechanism of secondary caries formation considering the tooth-composite interface as a unique complex in which each element has an influence on the other. [ABSTRACT FROM AUTHOR]

Purpose: Thanks to adhesive techniques and strengthened glass ceramics, ultrathin bonded occlusal veneers have been recently introduced. However, since a universally accepted thickness limit for ultrathin ceramics has yet to be established, their resistance to fracture needs to be better investigated. The purpose of this in vitro study was to evaluate the effect of dentin bonding on the flexural properties (ie, fracture load and flexural strength) of a lithiumdisilicate (LD) glass ceramic when used in thicknesses equal to or less than the manufacturer's recommendations for occlusal restorations. Materials and Methods: A total of 96 dentin slices (2.0 mm thick and 15 mm long) were obtained by sectioning bovine teeth along their long axes. LD slices of different thicknesses (1.5 mm/1.3 mm/1.0 mm/0.8 mm/0.6 mm) and 15 mm in length were cut from CAD/CAM LD blocks (IPS e.max CAD-C16). In each of 5 experimental groups, 16 dentin slices were adhesively luted to 16 LD slices (n = 16) of the same thickness, in order to create 16 bi-layered dentin-LD bonded assemblies. In the control group, the 16 remaining dentin slices were conventionally cemented to 1.5-mm-thick LD slices (n = 16) using a resin-modified glass-ionomer cement (FujiCEM 2). All dentin-LD assemblies were cut perpendicularly to their joint interface, in order to obtain 1-mm-wide, 15-mm-long bi-layered prismatic beams, having the following final thicknesses: for the 5 experimental groups, 2 mm (dentin layer) + 1.5 mm/1.3 mm/1.0 mm/0.8 mm/0.6 mm (LD layer); for the control group, 2 mm (dentin layer) + 1.5 mm (LD layer). All prismatic beams were subjected to a three-point bending test (14-mm span, load applied on the LD side). Fracture loads (N) and flexural strengths (MPa) were recorded. Data were analyzed using one-way ANOVA on ranks tests (a = 0.05). The correlations between the recorded flexural strengths and the dentin:LD thickness ratio and between the flexural strength and the luting strategy were also investigated. The failure modes were observed and classified. Results: No statistically significant differences were recorded between the conventionally luted control group (LD thickness 1.5 mm; fracture load 35.26 N; flexural strength 60.44 MPa) and the thinnest adhesively luted experimental group (LD thickness 0.6 mm; fracture load 28.97 N; flexural strength 90.01 MPa) in terms of fracture load and flexural strength. A fracture involving both the dentin and the LD of the bi-layered prismatic beam, but without any debonding between the LD and the dentin substrates of the broken specimen, was the most common failure mode observed on the adhesively luted samples. Conclusion: Compared to conventional cementation, when LD is bonded to dentin, the flexural properties of the whole system are improved, and the two different substrates seem to behave like a single unit. Once adhesively luted, 0.6-mm-thick LD has the same fracture load and flexural strength as that of the conventionally luted 1.5-mmthick LD. [ABSTRACT FROM AUTHOR]

The influence of the layer thickness and composite shade on the final color of Ceram.X composites (Dentsply Sirona) was tested, selecting five intermediatetranslucency Ceram.X Universal shades, three high-translucency Ceram.X Duo "enamel" shades, and four low-translucency Ceram.X Duo "dentin" shades. Using cylindrical molds, 850 specimens were obtained, representing the whole array of possible Universal single specimens (in seven thicknesses, ranging from 1.0 to 4.0 mm in 0.5-mm increments) and Duo combinations. The CIELAB coordinates of each specimen were determined with a spectrophotometer. Different thicknesses and composites were compared with Clark's ΔE. The difference in color among specimens of different thicknesses was materialdependent. The thickness and shade of the composite markedly affected the color yield of the Ceram.X system. For each shade of the Universal systems, only one Duo enamel-dentin combination corresponded. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of pretreatment with different crosslinking agents on glass-fiber-post adhesive luting. Materials and Methods: Single-rooted human teeth (n = 20) were randomly assigned to four groups: proanthocyanidins (PA) from grape-seed extract, cardol and cardanol (separated from cashew nut-shell liquid) and negative control (hydroethanolic solution). The solutions were applied on 37% phosphoric acid-etched dentin for 60 s. Glassfiber posts were cemented using a three-step etch-and-rinse adhesive (Scotchbond Multi-Purpose, 3M Oral Care) and composite cement (RelyX ARC, 3M Oral Care). Slices for the push-out bond strength test were cut and tested after 24-h or 6-month storage in distilled water. The dentin underlying the adhesive layer was analyzed by micro-Raman spectroscopy to evaluate vibrational formation of collagen crosslinks. Three additional slices per group were also made and the adhesive in-situ degree of conversion (DC) was analyzed by micro-Raman spectroscopy. The results were analyzed using two-way ANOVA and Tukey's test (p < 0.05). Results: No statistically significant changes in bond strength were found over time for any of the groups, except with cardol, which increased bond strength (8.4 ± 3.9 MPa at 24 h to 15.0 ± 2.9 MPa after 6 months, p < 0.001) after aging. The formation of peaks at 1117 cm-1 and 1235 cm-1 showed the presence of collagen crosslinks for all three biomodification agents. The DC outcomes showed no statistically significant differences between groups (p = 0.514). Conclusion: Biomodification agents did not impair adhesive polymerization. Cardol demonstrated a positive influence on intraradicular dentin bonding for glass-fiber post luting. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of the etching strategy of universal adhesives on bond degradation to sound and artificially-induced caries-affected dentin. Materials and Methods: The universal adhesives (Scotchbond Universal Adhesive; All-Bond Universal; Prime&Bond Elect) and adhesives used as controls (Adper Single Bond 2 and Clearfil SE Bond) were applied to sound and artificially-induced caries-affected bovine dentin. Microtensile bond strength was evaluated immediately (24 h) and after one year of water storage (1 year). Representative specimens were also prepared to assess nanoleakage. Bond strength data (MPa) were analyzed using three-way ANOVA and post-hoc Tukey's test (α = 0.05), considering each substrate separately. Results: Bonding degradation was observed for all universal adhesives on caries-affected dentin, irrespective of the etching strategy. On sound dentin, bonding degradation was observed when adhesives were used on the etchand-rinse strategy. Conclusion: The universal adhesives were not capable of maintaining bond stability over time on caries-affected dentin. The self-etch strategy seems better able to maintain the durability of adhesive interfaces created on sound dentin. [ABSTRACT FROM AUTHOR]

Objective: To test the null hypothesis that dentine treatment with silver diamine fluoride (SDF), a potent antimicrobial agent, following use of proteolytic and chelating agents does not influence the wettability of an epoxy resin (AH Plus, Dentsply Sirona, Charlotte, NC, USA) and a tricalcium silicate sealer (BioRoot RCS, Septodont, Saint-Maur-des-Fossés, France). Methods: Seventy-two intraradicular dentine specimens were divided into six groups based on the final irrigation solutions used: 2.5% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA) (NaOCl-EDTA) (group 1); NaOCl-EDTA-NaOCl (group 2); NaOCl-EDTA followed by 3.8% SDF, NaOCl-EDTA-SDF (group 3); NaOCl-EDTA-NaOCl-SDF (group 4); SDF (group 5) and saline (group 6). After irrigation, the specimens were divided into subgroups according to the sealer used, AH Plus or BioRoot RCS. Contact angles were measured using a contact angle analyser. The data were analysed using an independent t test, one-way analysis of variance (ANOVA) and Tamhane T2 post hoc test, with the level of significance set at P < 0.05. Results: In the epoxy resin sealer group, dentine surfaces treated with only SDF showed the lowest contact angle. This was significantly less than the groups in which NaOCl was used as the final irrigant (P < 0.05). In the tricalcium silicate-based sealer group, the groups treated with SDF showed significantly greater contact angles when compared to the control group (P < 0.05). Conclusion: It was concluded that SDF conditioning of dentine favours the wettability of epoxy resin sealer but is detrimental to the wettability of tricalcium silicate sealer. [ABSTRACT FROM AUTHOR]

Purpose: There is little knowledge about healing patterns for the socket with an intentionally retained root fragment: a socket shield. The clinical observation is soft tissue ingrowth next to the socket shield. The aim of this study was to evaluate the effectiveness of autologous grafting matrices in preventing soft tissue ingrowth. Materials and Methods: Patient data from a private clinic were searched for sockets with a socket shield left to heal with blood clot or grafted with autologous materials: autologous platelet-rich fibrin (PRF), scraped particulate bone, cortical tuberosity bone plate, or particulate dentin and covered with PRF membranes. The included sites were exposed by the flap 4 months after the first surgery, and soft tissue ingrowth depth and width next to the root fragment were measured by a scaled probe and documented. Results: Evaluation of 34 sites showed the greatest depth of soft tissue ingrowth in the nongrafted sockets (6.0 ± 0.0 mm). Grafting with PRF plugs (depth of 2.3 ± 0.2 mm) or particulate bone (depth of 2.7 ± 0.6 mm) decreased soft tissue ingrowth. Grafting with particulate dentin or cortical tuberosity bone plate resulted in a soft tissue ingrowth depth of only 1 mm, yielding the best clinical outcome. Radiography confirmed those findings. Conclusion: Autologous dentin particulate or tuberosity cortical bone plate is most effective for preventing soft tissue ingrowth. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of root canal irrigants, dentin surface treatment, and timing of the restoration on the microtensile bond strength (μTBS) of a universal adhesive to deep coronal dentin. Materials and Methods: Ninety (90) intact molars were grouped according to the irrigation protocol: group 0 (saline, control group); group 1: 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) followed by 5.25% NaOCl; group 2: 18% etidronic acid (HEDP) + 5.25% NaOCl in a single mixture. Groups 1 and 2 were divided into 2 subgroups (n = = 10) according to the time of restoration: immediate (subgroup A) and after 7 days (subgroup B). Four other groups (n = 10) were created according to the dentin surface pretreatment and received an immediate restoration: group 3: 5.25% NaOCl - 17% EDTA and AH Plus Cleaner; group 4: 5.25% NaOCl - 17% EDTA and 100% ethanol; group 5: 5.25% NaOCl + 18% HEDP and AH Plus Cleaner; group 6: 5.25% NaOCl + 18% HEDP and 100% ethanol. μTBS testing was carried out for each subgroup and interfaces were analyzed through SEM. The μTBS was analyzed with Welch statistics and the post-hoc Games-Howell test for multiple comparisons (p < 0.05). Results: Statistically significant differences were observed between test groups and control groups (p < 0.001), except for group 3 (p = 0.349). No significant differences were recorded between groups 1A (27.5 ± 8.7 MPa), 2A (32.6 ± 14.5 MPa) and 3 (27.3 ± 14.3 MPa). Group 6 (48.6 ± 11.6 MPa) exhibited the highest μTBS among all tested groups. For groups 1 and 2, significantly higher values were recorded for subgroups 1B (39.3 ± 7.6 MPa) and 2B (43.8 ± 8.3 MPa) compared to subgroups 1A (27.5 ± 8.7 MPa) and 2A (32.6 ± 14.5 MPa). Conclusion: When using NaOCl as root canal irrigant, it is advisable to delay the placement of a post-endodontictreatment restoration. [ABSTRACT FROM AUTHOR]

Purpose: To systematically review in vitro studies that evaluated adhesive-dentin bond strength with or without the addition of desensitizers. Materials and Methods: A search was conducted in four databases (PubMed, Embase, Web of Science, and Cochrane Library) without publication date or language limits in accordance with the Preferred Reporting Items for Systematic Reviews (PRISMA). Two reviewers selected the studies, extracted data, and assessed the risk of bias independently. The inclusion criterion was the evaluation of the effect of immediate or aged bond strength after applying desensitizer in the bonding step. The risk of bias was assessed following the method used by Sarkis-Onofre et al.41 Meta-analysis was conducted using Review Manager 5.3. Results: A total of 1636 articles were found using the search strategy above; 59 articles were selected for full-text analysis, and 32 were systematically reviewed, with 18 considered in the meta-analysis. Results showed a significant difference among various kinds of desensitizers. The subgroup comparison showed high heterogeneity among the different kinds of desensitizers. The use of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and arginine-CaCO3 showed no negative effect on the immediate bond strength, whereas other desensitizers showed some influence. Conclusion: Different desensitizers have various effects on microtensile bond strength. Desensitizers may be selected based on the bond strength and especially used to relieve tooth sensitivity after tooth preparation. [ABSTRACT FROM AUTHOR]

Currently, there is a trend towards simplification of materials and clinical procedures. Simplification and quality can go together if the dentist works with materials and techniques that are well proven in vitro and in vivo. The placement of a high-quality class-1/2 direct posterior composite restoration can be time efficient following a standardized layering protocol and using composite materials that adapt well to the tooth surface and are able to mimic the natural tooth. When these materials are applied in a controlled way, finishing and polishing can also be shortened. In this article, an effective layering and finishing/polishing protocol for medium-sized class-1/2 direct posterior composite restorations is presented. Following the histo-anatomic buildup of natural teeth, dentin must be concave, as opposed to convex enamel. An isochromatic, medium-opaque, highly filled flowable composite is used to replace dentin. Enamel is replaced with a medium-translucent small-particle hybrid composite. Enamel is modelled in an anatomical way, following a successive cusp-by-cusp buildup approach. Clinical experience shows that the combination of both materials used according to this so-called bi-laminar histo-anatomical layering approach results in restorations that blend in very well within the surrounding tooth structure. Following a simplified finishing and polishing protocol, the composite restorations will have a correct contour, seamless margins, and a smooth, glossy surface. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of application of a primer resembling a universal adhesive with or without light irradiation followed by a hydrophobic bonding agent on bonding effectiveness, based on shear bond strength (SBS) and shear fatigue strength (SFS) tests. Materials and Methods: An experimental two-step self-etch adhesive (BZF) that comprises a primer resembling a universal adhesive (BZP) and a hydrophobic bonding agent (BZB) were used. The two-step self-etch adhesive, Clearfil SE Bond 2 (SE), served as a comparison. Three experiments were conducted. Experiment 1: (1) BZP alone without light irradiation (BZP w/o); (2) BZP alone with light irradiation (BZP w/); (3) BZP without light irradiation followed by BZB (BZPB w/o); (4) BZP with light irradiation followed by BZB (BZPB w/). Experiment 2: (1) BZPB w/o, (2) SE primer + BZ bonding agent (SEP+BZB), and (3) SE primer+SE bonding agent (SEPB). The bonded specimens of experiment 1 and 2 were subjected to SBS tests. Experiment 3: Bonded specimens following the same experimental protocol as experiment 2 were subjected to SFS tests. Results: BZPB showed significantly higher mean enamel and dentin SBS than did BZP. BZPB showed significantly higher SBS without light irradiation than with light irradiation to both substrates. The group of BZPB without light radiation showed significantly higher SBS than the group of BZPB with light irradiation to both substrates. For experiments 2 and 3, although no significant differences were found in SBS among groups for enamel, SEP+BZB showed a significantly lower SBS and SFS than other groups for dentin. Conclusions: BZF showed bonding performance equivalent to that of the gold standard Clearfil SE Bond 2. [ABSTRACT FROM AUTHOR]

Aim: Dental bleaching could adversely affect dentine hardness. The aim of the present study was to evaluate the effect of cervical dentine thickness on hardness reduction of outer dentine following intracoronal bleaching. Materials and methods: Thirty-six intact anterior teeth were selected and the root segments were separated 2 mm below the cementoenamel junction. Using a diamond fissure bar, dentine substrate was removed so that cervical dentine thickness in one part of the separated tooth was twice that in the other half. A resin-modified glass-ionomer cement plug was placed in 2-mm thickness from the apical side. Teeth were randomly divided into three groups (n = 12) to be treated with bleaching agents containing 35% hydrogen peroxide, sodium perborate, and distilled water in the control group. Vickers hardness numbers were measured for outer and inner dentine in each tooth sample. Data were analysed using Mann-Whitney U tests. Results: The mean Vickers hardness number between the two dentine thicknesses showed a statistically significant difference only in the sodium perborate bleaching group (P = 0.000). The mean Vickers hardness number of inner dentine was significantly higher in the small dentine thickness in comparison to the large dentine thickness (P = 0.000). The mean Vickers hardness number of outer dentine was significantly higher in the large dentine thickness in comparison to the small dentine thickness (P = 0.000). Conclusions: Within the limitations of this laboratory study, even in the presence of an orifice barrier, removal of excessive dentine from the root canal walls during root canal preparation could increase the damaging effect of bleaching materials on outer dentine microhardness. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the shear bond strength (SBS) and color stability (ΔE) of four ceramic veneers (VITA VM 9; VITA VM 13; VITA VMK 95; and IPS e.max Ceram) following repair with three different self-adhesive composite resins (Fusio Liquid Dentin; Constic; and Vertise Flow) and BISCO Intraoral Repair Kit + Filtek Supreme (BC + FS).Materials and Methods: A total of 96 specimens were prepared per ceramic material, and each ceramic group was divided into subgroups according to testing method (32 specimens for color stability analysis and 64 specimens for SBS testing). ΔE and SBS (SBS1 = non-aged, SBS2 = thermally aged) values of the repaired specimens were calculated. One specimen from each of the thermally aged groups was investigated under scanning electron microscopy (SEM). Two-way ANOVA was used to analyze the mean ΔE, SBS1, and SBS2 values. The differences between SBS1 and SBS2 values were analyzed using independent-samples t test.Results: The lowest ΔE values were calculated for Constic (P ≤ .05). The SBS2 values among all groups were lower than the SBS1 values (P ≤ .05). The lowest SBS2 values were observed for Vertise Flow (2.3 ± 1.47 MPa) (P ≤ .05) and were below the acceptable limit of 5 MPa.Conclusion: All of the investigated repair materials in combination with the ceramic veneers exhibited ΔE values that were higher than the clinically acceptable limits. Thermal aging negatively affected the SBS values in all groups (P ≤ .05). All tested self-adhesive composite resins, with the exception of Vertise Flow, could be used instead of a repair kit with flowable composite resin, especially in noncooperative patients, for the purpose of repairing chipping fractures for VITA VM 9, VITA VM 13, and VITA VMK 95 (P > .05). [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to assess the perceptibility and acceptability threshold values for color differentiation at the restoration and mucosa levels.Materials and Methods: One restored single-tooth implant and the contralateral reference tooth were spectrophotometrically assessed in 20 patients. Perceptibility and acceptability were evaluated by dentists, dental technicians, and laypeople.Results: Dental technicians had the highest sensitivity in the perception of tooth color differences (ΔE = 2.7), followed by dentists (ΔE = 3.3) and laypeople (ΔE = 4.4). Acceptability threshold values were generally higher than perceptibility threshold in all groups. Dental technicians exhibited the highest sensitivity in the perception of mucosa color differences (50% perceptibility at ΔE = 2.65), followed by dentists (ΔE > 3.7) and laypeople (ΔE > 6).Conclusion: Color differences were tolerated with varying degrees among the three groups. Laypeople accepted higher color differences at the mucosa level. [ABSTRACT FROM AUTHOR]

Purpose: To investigate dentin abrasivity and cleaning efficacy of novel/alternative toothpastes containing diamond particles, active carbon, sea salt or organic oils.Materials and Methods: Seventy-two bovine dentin samples (for measuring abrasivity) and 60 human dentin samples (for assessing cleaning efficacy) were used in this study. Samples were divided into six groups as follows: group 1: Elmex Kariesschutz (hydrated silica); group 2: Lavera Neutral Zahngel (sea salt); group 3: Curaprox Black is White (active carbon); group 4: Swiss Smile Diamond Glow (diamond powder); group 5: Ringana Fresh Tooth Oil (hydrated silica); and group 6: artificial saliva. Samples were brushed for a total of 26 min at 120 strokes/min, replacing slurries (1 part respective toothpaste and 2 parts artificial saliva) every 2 min. Finally, abrasive dentin wear was measured profilometrically and cleaning efficacy planimetrically.Results: The highest abrasivity values were observed for Lavera Neutral Zahngel (sea salt 9.2 µm) and Elmex Kariesschutz group (hydrated silica 6.0 µm). The lowest abrasivity value was observed for Ringana Fresh Tooth Oil group (hydrated silica 1.3 µm). The highest cleaning efficacy was observed for Elmex Kariesschutz group (86.7%) and the lowest cleaning efficacy was observed for Ringana Fresh Tooth Oil group (31.3%).Conclusion: The addition of diamond powder or active carbon to toothpastes could offer high cleaning efficacy with low dentin abrasivity. The addition of sea salt to traditional abrasives might cause high abrasive dentin wear without adding further cleaning benefit. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether toothpastes with diamond powder vs those with traditional abrasives abrade dentin and enamel differently and to determine the relative dentin abrasivity (RDA) and relative enamel abrasivity (REA) values of those toothpastes.Materials and Methods: Dentin and enamel samples of bovine permanent incisors were randomly allocated into groups of eight, brushed with 20 different toothpastes (three of which contained diamond powder) and analysed for their RDA and REA values.Results: Toothpastes with diamond powder exhibit low RDA values but high REA values. Some RDA values exceeded the ones declared by the manufacturer.Conclusion: Diamond powder as an abrasive might have a mild action on dentin, but it is highly abrasive on enamel. [ABSTRACT FROM AUTHOR]

This in vivo study assessed the effect of mineral trioxide aggregate (MTA) as a matrix carrier for recombinant human platelet-derived growth factor (rhPDGF) and enamel matrix protein (EMP) on pulp tissue healing following pulp capping. Eighteen intact human premolars scheduled for extraction were included. Coronal access and pulpotomy were performed, and each tooth was left exposed to the oral cavity for 1 hour before pulp capping was performed. Teeth were randomly assigned to one of the following pulp-capping groups (n = 6 each): Group 1 (MTA only); Group 2 (MTA+EMP); or Group 3 (MTA+rhPDGF). Coronal access cavities were then sealed. Immediate preoperative, postoperative, and 4-month follow-up radiographs were taken. At 4 months, the teeth were extracted atraumatically, and histomorphometric and micro-computed tomography (µCT) analyses were performed. Group 1 showed a thin, uneven, irregular dentin-like structure. Its average thickness was 0.3 ± 0.084 mm measured histologically and 0.29 ± 0.091 mm measured by µCT. Group 2 showed of a nonporous, even-thickness dentin-like structure with multiple root-canal obliterations. Highly dense, atubular dentin-like structures associated with presence of odontoblastic lacunae were seen. The structure's average thickness was 0.87 ± 0.09 mm (histologically) and 0.81 ± 0.17 mm (µCT). Group 3 showed a thick and complete 3D continuous seal of newly formed dentin-like structure covering the pulpal space. It resembled secondary dentin in form, porosity, and tubular structural organization, and its average thickness was 0.94 ± 0.02 mm (histologically) and 0.91 ± 0.09 mm (µCT). Groups 2 and 3 showed higher amounts of newly formed dentin-like structure, that was also thicker, than Group 1 (P < .05). No statistically significant differences in structure thickness were found between Groups 2 and 3. The nature of the structure can differ if rhPDGF or EMP is added to MTA for pulp-capping purposes. Combination of rhPDGF and MTA resulted in a newly formed structure resembling secondary dentin, whereas a combination of EMP and MTA produced a nonporous, highly dense dentinal-like structure associated with significant root-canal obliterations. [ABSTRACT FROM AUTHOR]