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Objectives: To evaluate the effects of enhanced personal protective equipment (Enhanced_PPE) on student‐operator's experience and restorative procedure. Methods: Student‐operators (N = 29 Year 3 dental students) performed Class II composite restorations (SimpliShade, Kerr) in typodont upper molars (OneDental) equipped with N95 respirators, full‐face shields, disposable headwear and gowns (Enhanced_PPE) or surgical masks, protective glasses/goggles and non‐disposable gowns (Standard_PPE) 2 weeks later. Cavity dimensions were measured on cone beam computed tomography images. The quality of composite restorations was assessed using selected FDI criteria and Vickers hardness. A questionnaire assessed the operators' discomfort, anxiety, confidence, ability to perform, and procedure outcome. Data were analyzed using paired t‐test and McNemar test (alpha = 0.05). Results: Student‐operators experienced greater discomfort and anxiety, reduced confidence and ability to perform, and rated the procedure as less satisfactory with Enhanced_PPE (p < 0.05). Differences in proximal box width were marginally significant (Enhanced_PPE 1.8 ± 0.4 mm, Standard_PPE 1.6 ± 0.3 mm) (p = 0.047). Other cavity dimensions were similar between groups (p > 0.05) as were restorations regarding surface luster, anatomical form, marginal adaptation, proximal contour, and contact (p > 0.05). There were no differences in the hardness of composite restorations (top p = 0.349, bottom p = 0.334). Conclusions: Enhanced_PPE led to student‐operator discomfort, anxiety, and reduced confidence, but did not impact the quality of Class II preparation and composite restorations versus Standard_PPE. [ABSTRACT FROM AUTHOR]

This study aimed to compare the biological properties of newly synthesized cements based on calcium phosphate with a commercially used cement, mineral trioxide aggregate (MTA). Strontium (Sr)-, Copper (Cu)-, and Zinc (Zn)-doped hydroxyapatite (miHAp) powder was obtained through hydrothermal synthesis and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectrometry (EDX). Calcium phosphate cement (CPC) was produced by mixing miHAp powder with a 20 wt.% citric acid solution, followed by the assessment of its compressive strength, setting time, and in vitro bioactivity. Acetylsalicylic acid (ASA) was added to the CPC, resulting in CPCA. Biological tests were conducted on CPC, CPCA, and MTA. The biocompatibility of the cement extracts was evaluated in vitro using human dental pulp stem cells (hDPSCs) and in vivo using a zebrafish model. Antibiofilm and antimicrobial effect (quantified by CFUs/mL) were assessed against Streptococcus mutans and Lactobacillus rhamnosus. None of the tested materials showed toxicity, while CPCA even increased hDPSCs proliferation. CPCA showed a better safety profile than MTA and CPC, and no toxic or immunomodulatory effects on the zebrafish model. CPCA exhibited similar antibiofilm effects against S. mutans and L. rhamnosus to MTA. [ABSTRACT FROM AUTHOR]

Objective: To measure degree of conversion (DC) of a flowable composite, microtensile bond strength (MTBS) to dentine in the snow‐plow technique with/without preheating and temperature in the preheated composite. Materials and Methods: For DC, snow‐plow specimens of Filtek Ultimate Flowable (Flow) and Filtek Bulk Fill (Bulk) (3M) were prepared by light‐curing composites simultaneously in standardized molds while in control groups light‐curing was separate. DC of Flow was measured using micro‐Raman spectroscopy. For MTBS, specimens were prepared on dentine of human extracted molars by simultaneous (snow‐plow) or separate (control) light‐curing. MTBS was measured using a universal testing machine after 24 h and 6 months. Data were analyzed using ANOVA with Tukey's post hoc (α = 0.05). Results: Increased curing time significantly increased DC in snow‐plow from 13.4% ± 11.6% (10 s) to 31.8% ± 4.4% (40 s) albeit significantly lower than controls (p < 0.05). Preheated Bulk improved conversion in snow‐plow (44.3% ± 1.7%) and control (50.5% ± 2.6%) (p < 0.05). No significant differences occurred in MTBS between groups (p > 0.05). MTBS values ranged between 66.7 ± 8.4 MPa (snow‐plow group_21°C_baseline) and 54.1 ± 15.8 MPa (control_21°C_long‐term). Temperature in the preheated Bulk dropped to ~38°C after 30 s. Conclusions: Snow‐plow technique, irrespective of preheating, resulted in lower DC of Flow than separate light‐curing of composite increments. Snow‐plow, irrespective of preheating, resulted in similar initial and long‐term MTBS to dentine. Clinical Significance: Clinicians with preference for flowable composite liners in Class II restorations should be aware that the snow‐plow technique of simultaneous light‐curing of flowable and bulk‐fill composite increments affects monomer‐to‐polymer conversion, albeit no effect on immediate, and long‐term bonding to dentine was detected. Preheating sculptable bulk‐fill composite improves conversion of the flowable liner in the snow‐plow technique but has no detectable effect on bond strength to dentine. [ABSTRACT FROM AUTHOR]

The objective of this study was to measure temperature changes in the pulp chamber induced by polymerization of resin-based dental restoratives following a simulated procedure of direct pulp capping. Class I cavities with a microperforation at the pulp horn were prepared in extracted human molar teeth. The complete procedure of direct pulp capping and cavity restoration was performed with the root part of extracted teeth fixed in a water bath at 37 °C. Mineral trioxide aggregate, bioactive dentin substitute or calcium-hydroxide paste were used as pulp capping materials. Cavities were restored with a light-cured or chemically-cured resin-modified glass ionomer, universal adhesive and a bulk-fill composite, cured with a high-intensity LED unit. Pulp capping materials caused a slight temperature decrease. Lower temperature increase was recorded during light-curing of the glass ionomer liner after direct capping with mineral trioxide aggregate and calcium-hydroxide than that recorded for the bioactive dentin substitute. Adhesive light-curing increased temperature in all groups with higher mean temperatures in groups with chemically-cured as compared to those for the light-cured glass ionomer liner. Direct pulp capping with mineral trioxide aggregate or calcium-hydroxide followed by the light-cured resin-modified glass ionomer liner and a bonded bulk-fill composite restoration induced temperature changes below the potentially adverse threshold of 42.5°C. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172007]

This study aimed to (1) comparatively analyze properties of Sr‐ and Mg‐substituted hydroxyapatite (HAP)‐based dental inserts; (2) evaluate insert bonding to restorative materials, and (3) evaluate the effect of doped HAP inserts on fracture resistance (FR) of human molars with large occlusal restorations. By ion‐doping with Sr or Mg, 3 insert types were obtained and characterized using XRD, SEM, Vickers hardness and fracture toughness. Shear bond strength (SBS) was determined between acid etched or unetched inserts and following materials: Maxcem cement (Kerr); Filtek Z250 (3M) bonded with Single Bond Universal (SBU; 3M) or Clearfil Universal (Cf; Kuraray). Modified Class I cavities were prepared in 16 intact molars and restored using insert + composite or composite only (control) (n = 8/group). FR of restored molars was determined by static load until fracture upon thermal cycling. Fracture toughness was similar between Sr/Mg‐doped inserts (0.94–1.04 MPam−1/2p =.429). Mg‐doped inserts showed greater hardness (range 4.78–5.15 GPa) than Sr6 inserts (3.74 ± 0.31 GPa; p <.05). SBS for SBU and Cf adhesives (range 7.19–15.93 MPa) was higher than for Maxcem (range 3.07–5.95 MPa) (p <.05). There was no significant difference in FR between molars restored with insert‐containing and control restorations (3.00 ± 0.30 kN and 3.22 ± 0.42 kN, respectively; p >.05). HAP‐based inserts doped with Mg/Sr had different composition and mechanical properties. Adhesive bonding to inserts resulted in greater bond strength than cementation, which may be improved by insert acid‐etching. Ion‐doped HAP inserts did not affect FR of restored molars. In conclusion, HAP‐based dental inserts may potentially replace dentin in large cavities, without affecting fracture resistance of restored teeth. [ABSTRACT FROM AUTHOR]

Objectives. This retrospective study evaluated the factors influencing the clinical failure of noncarious cervical lesion (NCCL) restorations. Methods. Patients were routinely treated by undergraduate or postgraduate students and randomly received a clinical recall evaluation. A retrospective study was performed with two experienced calibrated examiners to evaluate NCCL restorations, including the critical parameters of retention, caries, marginal discoloration, and marginal integrity. The factors related to the restoration included gender, age, arch site, tooth position, the presence of occlusal wear facets, caries risk, operator, adhesive strategy, and composite. The clinical failure comparison between the parameters and factors was performed using the binary logistic regression analysis. Results. A total of 460 cervical restorations from 96 patients were evaluated. The adhesive strategy and the presence of occlusal wear facets were the most important factors influencing the parameter failure. Therefore, the highest failure was marginal integrity, in which the gingival marginal integrity failure was 50.7%, and the occlusal marginal integrity failure was 42.4%. Conclusions. The main factors influencing clinical failure for partial loss, marginal discoloration, and marginal integrity were the adhesive strategy and the presence of occlusal wear facets. Therefore, marginal integrity was the most frequent failure parameter. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare color changes, surface roughness and gloss of a microhybrid and nanohybrid composite whitened in a simulated in-office or at-home procedure using 40% hydrogen peroxide or 16% carbamide peroxide, respectively. CIELab coordinates were measured before, during and after treatment using VITA EasyShade V (VITA) and ΔE00 calculated. Surface roughness was measured using a surface roughness tester (SJ210; Mitutoyo). Gloss was measured using a gloss checker (IG-331; Horiba). At-home whitening resulted in ΔE00 of 1.23±0.49 (microhybrid) and 1.01±0.76 (nanohybrid). In-office exposure resulted in ΔE00 of 0.69±0.38 (microhybrid) and 0.72±0.50 (nanohybrid). There were no significant differences in ΔE00, surface roughness and gloss between whitening protocols (p>0.05). Color changes of a microhybrid and nanohybrid composite following simulated in-office or at-home whitening reached CIEDE2000 50:50% perceptibility but not acceptability threshold. Surface roughness and gloss of the microhybrid and nanohybrid composite were not affected by whitening. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to compare the use of periodontal probing and cone beam computed tomography (CBCT) images in the diagnosis of furcation involvement (FI) in patients with chronic generalized severe periodontitis. Method and Materials: Fifteen patients with chronic generalized severe periodontitis were included in this study. In total, 174 furcation sites (all in molar teeth) were analyzed. FI was assessed at three sites (buccal, mesiopalatal, and distopalatal) of maxillary molars, and at two sites (buccal and oral) of mandibular molars. FI was assessed both clinically (periodontal probing) and on CBCT images, using a dichotomous scale (present/absent). The agreement between clinical and CBCT-based findings was calculated. Results: FI were more often detected by means of CBCT than by means of clinical examination. Agreement between the evaluation methods was present in 46.9% of cases (63.3% in maxilla, 45.0% in mandible). FI detected clinically was confirmed by means of CBCT in 24% of the evaluated sites. The largest agreement (73.7%) in FI detection was found in the distopalatal maxillary sites between CBCT and clinical probing. The smallest agreement (36.6%) was found in the buccal sites of the mandibular molars, in which 63.3% of FI were detected using CBCT only, but not clinically. Conclusion: The number of FI detected by means of CBCT was larger than by means of periodontal probing. In those cases in which chronic generalized severe periodontitis is clinically diagnosed, and surgical treatment is necessary, CBCT may be suggested as an adjunct tool for FI assessment. [ABSTRACT FROM AUTHOR]

Objective: To analyze the effects of factors 'composite,' 'medium,' and 'time' on color, translucency, and sorption/solubility of sculptable universal composites for enamel layering upon immersion in colored beverages. Materials and methods: Disk‐shaped specimens, 10 mm in diameter and 2 mm thick (n = 5/group), of ultrafine, hybrid composite Essentia (GC), microhybrid Gaenial Anterior (GC), nanofilled Filtek Ultimate Enamel and Body (3M ESPE) were immersed in red wine, coffee, or distilled water for 15 days. CIELab color coordinates were measured and CIEDE2000 (∆E00) and Translucency Parameter differences (∆TP00) were calculated. Sorption and solubility were determined according to ISO 4049:2009. Data were analyzed using the analyses of variance and Tukey's post‐hoc test (α = 0.05). Results: Essentia and Gaenial exhibited the lowest and the highest staining‐dependent color differences, with mean ∆E00 range of 1.7–6.1 and 5.1–11.3, respectively (p < 0.05). ∆TP00 was more pronounced in wine than in coffee (p < 0.05). Sorption and solubility varied between 9.8 and 15.3 μg/mm3 and −1.6 and −5.4 μg/mm3, respectively, with positive correlation between ∆TP00 and sorption (p = 0.005). Conclusions: Total color and translucency differences of sculptable composites for enamel layering were material‐, time‐ and medium‐dependent. Translucency differences positively correlated with sorption. Overall, the ultrafine, hybrid composite exhibited the best results in terms of color stability, sorption and solubility. Clinical significance: Clinicians should be aware of differences in color stability of sculptable composites for enamel layering as these are directly exposed to discoloration in the oral environment and are directly related to patients' long‐term satisfaction and restoration longevity. Ultrafine, hybrid composite may be preferred due to better color stability, lower sorption and solubility compared to nanofilled and microhybrid composites evaluated in this study. [ABSTRACT FROM AUTHOR]

The application of sintered calcium phosphate dental inserts in the central part of tooth cavities can reduce amount of embedded dental composite and polymerization shrinkage of final dental fillings. The aim of this study was to analyze comparatively physico‐chemical and mechanical properties of dental inserts and shear bond strength (SBS) between three dissimilar hydroxyapatite‐based dental inserts and different restorative materials, after application of different clinical protocols. Starting from two different hydroxyapatite nano powders and nanostructured stabilized zirconia (YSZ), monophasic two‐step sintered dense HAp inserts (TSSHAp), biphasic single‐step sintered controlled porous inserts (HAp/TCp), and single‐step sintered reinforced HAp/YSZ inserts were processed and characterized. Obvious differences in the microstructure of inserts surface were visualized after etching with 37% phosphoric acid. Fracture toughness of sintered inserts was ranged between 1.01 and 1.85 MPam1/2 (maximum value in the case of HAp/YSZ), while hardness values were in the range of 3.71–5.22 GPa (maximum value in the case of TSSHAp). Acid etching before application improved SBS between inserts and Maxcem compared to direct cement application. TSSHAp and HAP/TCp inserts showed comparable and relatively high SBS values, certainly higher compared to HAp/YSZ inserts. Slightly higher SBS values were measured in the case of TSSHAp insert group, and the highest mean SBS value of 18.51 MPa was determined between TSSHAp inserts and Filtek Z250_SBU following the "self‐etch" protocol. [ABSTRACT FROM AUTHOR]

Objective: To analyze local shrinkage patterns in terms of surface shrinkage strains and z-axis displacements in a novel self-adhering composite and a conventional flowable composite using three-dimensional digital image correlation. Method and Materials: Seven samples of each material were prepared in cylindrical Teflon molds 5 mm in diameter and 2 mm thick. The surface of the composites facing the cameras was sprayed with a fine layer of black paint. The unsprayed surface of each sample, opposite the one facing the cameras, was light cured for 40 seconds using a light-emitting diode unit. Digital images were taken immediately before and after light curing. Shrinkage was calculated as von Mises strains, and z-axis displacements were measured in microns. The data were statistically analyzed using two-way ANOVA at α = .05. Results: No significant difference in strain was observed between the two materials (P > .05). Strain distribution was nonhomogenous-- the outer segments showed significantly higher strains than central parts in each material (P < .05). The opposite was observed for z-axis displacements--significantly greater displacements were found in central parts compared to the outer segments (P < .05). Conclusion: Different shrinkage vectors across the surface of the tested flowable composites showed predominant in-plane shrinkage of the outer surface segments and out-of-plane shrinkage of the inner segments. These complex local deformation patterns in composite materials indicate zones of different types of forces exerted on the tooth-restoration interface in situ. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to compare the ratio of carbon-carbon double bonds (RDB) of two adhesive systems cured by five different light-curing units (LCUs) using micro-Raman spectroscopy. Materials and Methods: Ten samples of an etch-and-rinse (Excite), a two-step self-etching adhesive system (AdheSE) - ie, primer and bond mixed - and AdheSE Bond only were prepared and cured with one of the following LEDs: Elipar Freelight2; Bluephase; SmartLite; Coltolux, each for 10 s; or a conventional halogen Prismetics Lite for 10 s or 20 s. Micro-Raman spectra were obtained from uncured and cured samples of all three groups to calculate the RDB. Data were statistically analyzed using ANOVA. Results: The mean RDB values were 62% to 76% (Excite), 36% to 50% (AdheSE Primer+Bond) and 58% to 63% (AdheSE Bond). At 20 s, Prismetics Lite produced significantly higher RDB in Excite than the other LCUs and Prismetics Lite at 10 s (p < 0.05). Prismetics Lite at 20 s and Elipar produced comparable RDB values of AdheSE Bond and AdheSE Primer+Bond (p > 0.05). Excite showed significantly higher RDB values than AdheSE (p < 0.05) whilst AdheSE Bond showed significantly higher RDB than AdheSE Primer+Bond (p < 0.05). Conclusion: The etch-and-rinse adhesive cured with the halogen LCU for 20 s gave higher conversion than LED LCUs or halogen for 10 s curing time. The highest intensity LED [Elipar] produced higher or comparable conversion compared to the lower intensity LED LCUs for the same curing time. The etch-and-rinse adhesive showed higher RDB than the self-etching adhesive system. The presence of the primer in the self-etching adhesive compromised polymerisation. [ABSTRACT FROM AUTHOR]

Objective: To determine color changes in bulk‐fill composite and universal composite restorations with dissimilar dentin replacement materials in extracted teeth after staining in red wine. Materials and Methods: Cylindrical, 4 mm deep, class I cavities were prepared in 140 human molars. Bottom 2 mm was restored with Biodentine (Septodont), everX posterior (GC) or experimental HAP inserts. Each dentin replacement material was covered with a 2‐mm layer of a universal composite Filtek Z250 or Z550 (3M ESPE) or Gradia Posterior (GC). Groups combining top composite layer and the underlying dentin replacement were designated as "composite_dentin replacement." Filtek Bulk Fill (3M ESPE) and Tetric EvoCeram Bulk Fill (Ivoclar Vivadent) were placed as a single 4‐mm layer. Color measurements were performed using Vita Easyshade 4.0 (Vita Zahnfabrik) initially and after 48‐hours storage in red wine at 37°C. Results: Color differences (ΔEoo) ranged between 2.1 ± 0.7 (Z250_HAP) and 7.8 ± 1.1 (Z550_everX). EverX resulted in higher ΔEoo of the overlying composite than HAP (P < .001) and Biodentine (P = .006). Generally, ΔEoo was affected more by decreasing lightness (ΔL′) than changes in chroma (ΔC′). Conclusions: EverX resulted in higher ΔEoo of the restoration than Biodentine and experimental HAP after staining in red wine. No significant differences in ΔEoo may be expected in different composites with the same underlying dentin replacement material. The same was generally true for bulk‐fill and universal composites. Clinical Significance: Similar extent of color changes may be expected in bulk‐fill and universal composites. Highly translucent everX might exhibit greater color differences irrespective of the capping composite than non‐translucent materials. Clinicians have a wider choice of composite materials to cover a particular dentin replacement material, for example, everX or Biodentine, as similar color differences may be expected in various overlying composite brands. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim of this study was to test long‐term microtensile bond strength (µTBS) of 2 universal adhesives applied to dentin following “total‐etch” (TE) or “self‐etch” (SE) protocols and aged by direct or indirect water exposure using simulated pulpal pressure. Materials and methods: Single Bond Universal (SBU, 3M ESPE) or Ipera Bond (IP, Itena) were applied to mid‐coronal dentin (“flat dentin”) or Class I cavity (“cavity dentin”) following TE or SE protocols in 112 extracted human third molars. Sixteen groups (n = 7 per group) were prepared, 8 groups for µTBS measurements after 24 hours, and further 8 groups for measurements after 6 months storage. “Cavity dentin” groups were subjected to simulated hydrostatic pulpal pressure of 15 cm H2O using a custom‐made device before cutting 1 × 1 mm sticks while “flat dentin” groups were cut into sticks and directly exposed to deionized water. Results: Generally, the TE protocol resulted in highest µTBS values on flat dentin initially for both adhesives (general linear model, P < .05). Long‐term storage resulted in significantly lower µTBS values for the TE protocol (P < .05) while the SE protocol showed comparable values after 6 months (P > .05). “Cavity dentin” with simulated pulpal pressure resulted in lower µTBS than “flat dentin” (P < .05). For both adhesives, µTBS was in the range of 19‐42 MPa initially and 16‐36 MPa after 6 months storage. Conclusions: µTBS to dentin of universal adhesives is more stable in the long term following the SE than TE protocol. Simulated pulpal pressure and cavity‐type sample preparation may be recommended for µTBS testing as a more clinically relevant strategy. Clinical Significance: Microtensile bond strength to dentin of universal adhesives appears more stable following the “self‐etch” than “total‐etch” protocol after long‐term degradation. More clinically relevant data may be obtained using simulated pulpal pressure and cavity‐type sample preparation in the study design. [ABSTRACT FROM AUTHOR]