This systematic review evaluates the marginal integrity of flowable and packable bulk fill composite materials placed in class II cavities. Electronic databases inclusive of MEDLINE, Scopus, and Web of Science were searched without restriction to date. The titles and abstracts of publications gathered from database searches were screened by reviewers according to the inclusion and exclusion criteria. From as initial yield of 142 articles ten studies were subject to qualitative analysis. The authors emphasized that marginal integrity in enamel and dentin does not significantly differ between flowable and packable bulk fill composites used for class II restorations. Moreover, their marginal integrity was comparable to conventional resin composites with incremental techniques. The adhesive system used with a total etch technique and assessed margin located in enamel resulted in better marginal integrity.

Additive manufacturing (AM) processes are increasingly used in dentistry. The underlying process is the joining of material layer by layer based on 3D data models. Four additive processes (laser stereolithography, polymer jetting, digital light processing, fused deposition modeling) are mainly used for processing dental polymers. The number of polymer materials that can be used for AM in dentistry is small compared to other areas. Applications in dentistry using AM are limited (e.g. study models, maxillo-facial prostheses, orthodontic appliances etc.). New and further developments of materials are currently taking place due to the increasing demand for safer and other applications. Biocompatibility and the possibility of using materials not only as temporarily but as definitive reconstructions under oral conditions, mechanically more stable materials where less or no post-processing is needed are current targets in AM technologies. Printing parameters are also open for further development where optical aspects are also important.

This study evaluated the physical and mechanical properties of a dental stone mixed by shaking. A shake-mix dental stone (Shake! Mix STONE; SM) was characterized in comparison with three conventional dental stones. The fluidity at pouring time, setting time, density, powder particle distributions, linear setting expansion, compressive strength and surface reproduction of detail for dental stones were investigated. The marginal adaptations of cast crowns to dies made with each stone were also determined. SM had higher fluidity and faster setting time than the other stones (p<0.05). The setting expansion of SM at 2 h was lower than those of other two stones (p<0.05). The 15-min compressive strength of SM was higher than the others (p<0.05). There were no significant differences in the marginal adaptations of the cast crowns fabricated using all the stones (p>0.05). In spite of the different mixing method, the shake-mix type dental stone had comparable physical and mechanical properties to the conventional dental stones.

The aim of the present study was to evaluate how hydroabrasion performs during composite removal. A standardized amount of composite was bonded to 40 enamel surfaces of extracted third molars, then removed with either a tungsten carbide bur mounted on a micro-motor handpiece without irrigation, a tungsten carbide bur mounted on a micro-motor handpiece with irrigation, a tungsten carbide bur mounted on an air-rotor handpiece, or hydroabrasion. The four treatment methods were compared using the enamel-surface-index and the adhesive-remnant-index and performing a Kruskal-Wallis statistical test to detect differences between each method’ scores. Hydroabrasion produced significantly less damage to the enamel surface compared to the other three methods. Hydroabrasion was the cleaning method that produced less damages to the enamel surface, at a cost of a less efficient composite removal than tungsten carbide burs on micro-motor handpiece.

Chemical transitions after atmospheric pressure plasma irradiation were investigated by evaluating intermolecular attractions and atomic and molecular reactions. Gold, titanium and stainless-steel alloy samples were ground with #800 grit SiC waterproof paper and nitrogen gas atmospheric plasma irradiation was conducted. The surface free energies of the treated alloys were calculated and compared statistically. X-ray photoelectron spectroscopy analysis was performed.The surface free energies of all metal surfaces treated by plasma irradiation were 1.5-times higher than those of the untreated metals. The energy of the hydrogen bonding component increased, and all alloy surfaces were coated with metal oxide after only a short period of plasma irradiation. The surfaces oxidized by plasma exhibited a high active energy, mainly due to an increase in the hydrogen bonding component. Reactions with oxygen in the air were promoted on the clean surfaces with exposed reactive elements.

The aim was to determine the fracture-behavior of incisors restored with different post-core foundations and crown made of conventional composite (PFC, G-aenial Anterior). Forty bovine-incisors were cut and divided into 5 groups. Group A had teeth restored using fiber-post and Gradia Core as core build-up and crown of PFC. Group B contained teeth restored with fiber-post and core made of everX Flow and crown of PFC. In Group C, the teeth were restored with everX Flow as post-core and crown of PFC. Group D, post-core-crown restorations were indirectly made from CERASMART. Group E, teeth were restored with Gradia Core as post-core and crown of PFC. Restored teeth were statically-loaded until fracture. ANOVA revealed that restoration technique significantly affected load-bearing capacity (p<0.05). Restored incisors (Group B) had the highest load-bearing capacity (443 N) among all groups. Using everX Flow as core material with fiber-post is promising to strengthen structurally compromised incisors.

Copper nanoparticles (NCu) were synthetized and added to commercial glass ionomer cement, to evaluate in vitro its antibacterial activity against oral cavity strains. The NCu were synthesized by copper acetate reduction with L-ascorbic acid and characterized by FTIR, Raman, XPS, XRD and TEM. Then, commercial glass ionomer cement (GIC) was modified (MGIC) with various concentrations of NCu and physicochemically characterized. Cell viability was tested against human dental pulp fibroblasts (HDPFs) by Alamar-Blue assay and antibacterial test was performed against S. mutans and S. sanguinis by colony forming unit (CFU) growth method. Synthesized NCu rendered a mixture of both metallic copper and cuprous oxide (Cu₂O). HDPF viability reduces with exposure time to the extracts (68–72% viability) and MGIC with 2–4 wt% NCu showed antimicrobial activity against the two tested strains.

This randomized clinical trial evaluated the efficacy of five different adhesive systems in the restoration of occlusal cavities after one year of function. Two etch-and-rinse (Optibond™FL, Prime&Bond^®NT™) and three self-etch (Clearfil™SE Bond, Xeno^®III, Xeno^®V⁺) adhesive systems were evaluated on 159 occlusal restorations, incrementally filled with a microhybrid composite resin. Restorations were assessed using the FDI criteria at baseline, 6 months and 1 year. Statistical analysis was performed with Friedman-test and Kruskal-Wallis test (p<0.05). At 1 year, 153 restorations were evaluated. A statistically significant decrease in the number of restorations with marginal adaptation classified as excellent occurred for the self-etch adhesives (p<0.01). Etch-and-rinse adhesives presented better performance than any of the self-etch systems (p<0.01) in terms of marginal adaptation. All cases were considered no less than satisfactory. Marginal adaptation was the most influent parameter on the distinctive performance of the adhesives where etch-and-rinse systems performed significantly better than self-etch systems.

The purpose of this study was to evaluate the effects of two different concentrations of silver diammine fluoride (SDF) on dentin bonding performance. Human mid-coronal dentin was treated with either distilled water (control), 3.8%SDF or 38%SDF for 3 min. A two-step self-etch adhesive and resin composite were applied according to manufacturer’s instructions. After thermocycling (TC) at 0, 5,000 and 10,000 cycles, microtensile bond strength (µTBS) testing and morphological assessment of resin-dentin bonding interface were performed. At 0 TC, µTBSs of 3.8% and 38%SDF were significantly reduced (p<0.05). At 5,000 and 10,000 TC, µTBSs of 3.8%SDF were comparable to those of the control group, whereas the µTBSs of 38%SDF were significantly lower (p<0.05). Acid-base resistance zone formation was observed in all groups, however, slope-shaped formation was identified only in the SDF groups. The µTBSs and interfacial morphology were influenced by concentration of SDF and also TC.

The aim of this study was to identify a physical property suitable for evaluating the orthodontic force by analyzing the physical properties of thermoplastic materials. Four thermoplastic materials were used: Essix A+^® Plastic (EA), DURAN^® (DU), Erkodur (ER), and Essix C+^® Plastic (EC). Finite element analysis (FEA), a water absorption test, constant strain loading test, X-ray diffraction (XRD) and Fourier transformation infrared spectroscopy analysis were conducted. FEA found a significant correlation between the elastic modulus and the orthodontic force. The water absorption of EC was significantly smaller than the other materials. EC showed no elastic modulus change. The XRD pattern indicated that EC was a crystalline polymer. FEA of thermoplastics showed that the elastic modulus is suitable for the evaluation of orthodontic force. The crystalline thermoplastic EC demonstrated a stable elastic modulus even under strain in a wet environment, suggesting the advantage of its use as an orthodontic aligner material.

The aim of this study was to construct a Ti-Nb-Cu ternary phase diagram that plays the role of a map for developing new titanium alloys with excellent machinability and mechanical properties. Fifteen experimental Ti-Nb-Cu ternary alloys composed of Ti-5–30%Nb-2–20%Cu were designed, and ingots made using Ar-arc melting furnace before casting to generate specimen. The alloy castings were evaluated in terms of their microstructures and alloy phases. A Ti-Nb-Ti₂Cu pseudo-ternary phase diagram was constructed using X-ray diffractmetry results. Three alloy phases (α-Ti, β-Ti and Ti₂Cu) were established within the specimen. Furthermore, the prescence of two-phase coexistence regions (α+Ti₂Cu, α+β and β+Ti₂Cu), and three-phase coexistence region (α+β+Ti₂Cu) was noted. The findings obtained through microstructural observation corresponded well with the constructed phase diagram.

This study aimed to evaluate the effects of artificial saliva contamination on a glass ionomer cement (GIC), a resin-modified GIC (RMGIC), and a composite resin (CR) that was used with two different etching adhesive systems. Three surface conditions were created on bovine teeth using artificial saliva: control (group I), mild saliva contamination (group II), and severe saliva contamination (group III). The microtensile bond strength (μTBS) of CR with dentin was significantly lower in group III than in group I. However, the μTBS of GIC and RMGIC with both enamel and dentin showed no significant intergroup differences. Moreover, CR exhibited significantly greater microleakage on cementum in group III than in group I, whereas both GIC and RMGIC showed no significant differences for both enamel and cementum. Thus, GIC and RMGIC may be suitable for preventing secondary caries after class V restorative treatments when contamination by saliva cannot be avoided.

The purpose of this study was to use a new scratch test and tensile test to evaluate the bond strength between artificial erosive enamel or dentin and self-adhesive resin composites as a coating material. Coronal enamel or dentin surface was exposed to an erosive cycle (artificial saliva [AS], pH:7.0 for 6.5 h and acidic carbonated beverages for 5 min, alternated 3 times per day) for the eroded-surface or stored in AS for the remineralized-surface. Two self-adhesive flowable resin composites, Fusio and LLB-CR6 (prototype), and a conventional flowable resin composite, BEAUTIFIL FLOW with self-etching primer system, Clearfil Mega Bond, were applied to enamel or dentin surfaces; and then the bond strengths were measured. For the eroded-surface, there were no significant differences in bonding strength among all materials, as assessed by the new scratch test. Thus, these self-adhesive flowable resin composites might be useful for coating materials on acid-eroded tooth surfaces.

The aim of this single-blind, parallel and randomized controlled trial was to evaluate the effect of Nanoseal^® application on root caries progression. Adult patients (n=129, mean age: 66.4±10.1 years) with root caries were randomly allocated into three groups: high-frequency (HF, n=43; intervention: Nanoseal application at baseline and 1–5 months), low-frequency (LF, n=43; intervention: Nanoseal application at baseline and 3 months), and control (n=43; intervention: no application of Nanoseal) groups. Measurements of fluorescence laser values of carious lesions using a DIAGNOdent™ Pen (D-value) were performed for each subject before intervention (baseline) and at 3 and 6 months. Significantly lower D-values for the HF (p=0.017) and LF (p=0.034) groups were observed compared with the control group at 6 months. Nanoseal application would be an effective procedure to suppress root caries progression.

This study evaluates the effects of resin infiltrant composition and caries histological zone on the hydrolytic degradation of resininfiltrated artificial bovine enamel caries (RI-AEC). Different resin infiltrants were tested (n=26 per group): Icon (G1); TEGDMA 60%, UDMA 20%, and HEMA 20% (TUH); TEGDMA 80% and HEMA 20% (TH); and TEGDMA 75% and Bis-EMA 25% (TB). Following caries infiltration, samples were cut perpendicularly, and transverse microhardness were analyzed (at two histological zones: surface layer and lesion body) before and after 21 days of water immersion. TB presented lower decrease in microhardness (due to hydrolytic degradation) than the other groups, with a large effect size (Hedge’s G from 0.83 to 1.19) and high power (84 to 99%). Neither histological zone nor its interaction with resin infiltrant composition significantly affected the outcome. In conclusion, resin composition affected microhardness of RI-AEC upon water immersion, and TB was the least affected.

To investigate applications of chitosan as antibacterial agent for endodontic treatments, we tested its activity against Enterococcus faecalis standard strain (ATCC29212) and clinical isolates. We determined the minimum bactericidal concentration (MBC) of 6 types of chitosan against ATCC29212; the most effective types were selected for further tests. Four clinical isolates were cultured from endodontically treated-teeth and identified by biochemical assays and polymerase chain reactions. Bacterial cultures were exposed to 1,700 and 2,100 kDa chitosan at MBC for 1, 3, 5, 10, and 60 min in time-kill assays and plated on brain-heart-infusion (BHI) agar for colony counts. Both types of chitosan showed significantly lower numbers of remaining bacteria (log colony forming units per millimeter, logCFUs/mL) than negative controls (0.1% acetic acid and BHI) at 10 min, and completely eliminated the bacteria at 60 min for all strains. Thus, chitosan could be developed as alternative biocompatible antimicrobial irrigant/medication for endodontic treatments.

To study the effect of central retainer shape and abduction angle during tooth preparation on stress distribution in endocrown-restored molars via finite element (FE) analysis, we constructed five FE models with different central retainer shapes and abduction angles. Under an oblique load, the distributions of maximum tensile stress in cervical dentin around the endocrown and on the cement layer, as well as maximum shear stress on the cement layer, were more balanced in the FE model in which the central retainer shape was generated based on the anatomical form of the pulp chamber. Moreover, there were no differences in stress distributions among FE models with different abduction angles. Therefore, the shape of the central retainer should be designed on the basis of the anatomical form of the pulp chamber; abduction angle during tooth preparation does not influence the repair effect of endocrown-restored mandibular molars.

This study assessed the impact of surface treatments and repair resin reinforcement with zirconium oxide nano-particles (nano-ZrO₂) on flexural strength (FS) of repaired denture base. A total of 320 heat-polymerized acrylic resin specimens were prepared and sectioned creating 2-mm gap. According to repair surface treatment, specimens were distributed into four groups: I) methyl methacrylate (M); II) alumina-blasted (AB); III) AB+silane coupling agent (SC); and IV) AB+methacrylate based composite bonding agent (MA). Groups were subdivided into 4 (n=20) according to nano-ZrO₂ concentration (0, 2.5, 5, 7.5 wt%). Half the specimens were thermo-cycled before testing. FS was determined by three-point bending test. Statistical analysis was done using ANOVA and Tukey-Kramer multiple comparison tests, with α=0.05. Alumina-blasting+(SC) or (MA) significantly increased FS of repaired specimens compared to control (p<0.05). All surface-treated specimens combined with nano-ZrO₂ reinforced repair resin significantly increased FS.

The experimental bioactive sealers were synthesized by incorporating fluoridated-nano-bioactive glass (F-nBG; 2.5 and 5wt%) in AH Plus^® (Dentsply DeTrey, Konstanz, Germany) sealer and denoted as AH-FBG2.5 and AH-FBG5, respectively. Structural pattern, setting time, flowability, and water sorption analysis were performed. The fluoride release behavior was evaluated periodically over the course of 40 days using inductively coupled plasma optical emission spectroscopy. For sealing ability, post-extraction single-rooted teeth were obturated with sealers. The percentage of voids and sealing ability were evaluated periodically using micro-computed tomography (micro-CT) followed by push-out bond strength. The Fourier transform infrared spectra showed a change in peak height with an increase in the concentration of fillers. The setting time, flowability, and water sorption of experimental groups were within the acceptable clinical range. The fluoride release, sealing ability, and bond strength of experimental sealers were significantly high. The experimental sealers have potential to overcome sealing ability issues of sealers.

This study evaluated the influence of an aqueous propolis-based solution (PROP) on gap formation and bond strength of posts bonded to root canal dentin using resin cements. Endodontically-treated bovine incisors received different irrigation protocols: 1) 2.5% sodium hypochlorite (NaOCl)/17% EDTA/NaOCl; 2) saline solution (NaCl)/EDTA/0.12% chlorhexidine (CHX); 3) NaOCl/PROP/NaOCl; 4) NaCl/PROP/CHX; 5) NaCl/PROP/NaCl. Posts were then bonded with cements: RelyX ARC; Panavia F2.0; or RelyX U200 (n=10). The specimens were cross-sectioned. Gaps were assessed and performed the push-out bond strength test. Surface roughness of dentin fragments was also evaluated. Statistical analysis was performed (5%). RelyX U200 exhibited greater gap-free interfaces. Bond strength varied as a function of cements and irrigation protocols. PROP irrigation had no negative effect on the bond strength (p>0.05). Roughness increased significantly after NaOCl/EDTA/NaOCl, but remained unaltered after PROP irrigation protocols. Propolis-based irrigation protocols do not interfere in the bonding performance of posts cemented to root canal dentin.

The aim of this study was to compare the effect of several commercially available disinfectants on the accuracy of various types of impression materials and their compatibility with gypsum including surface quality and structure evaluation. Four alginate and three elastomeric impression materials in combination with disinfectants Aseptoprint Liquid, Zeta 7 solution, Silosept and Dentaclean Form were tested. The dimensional changes, detail reproduction, the compatibility with gypsum and surface/subsurface morphology were evaluated using light microscopy, scanning electron microscopy and micro computed tomography. Two alginate materials disinfected in Dentaclean Form exhibited the most significant differences (p<0.0001). The loss of detail on some alginate impressions in combination with this disinfectant including deterioration and change of morphology of gypsum surfaces was observed. Porosity in subsurface area and exposed large particles were detected. It was confirmed that the desired properties of impressions may be negatively affected in combination with some disinfectants.

This study explored modification of an alkaline heat treated titanium surface, using magnesium ions, to improve bone compatibility through the sustained release of magnesium ions. Pure titanium surface was first subjected to alkaline treatment using 5 M NaOH then modified with magnesium through immersion in magnesium chloride solution before heating in a furnace at 600°C for 1 h. Use of at least 0.01 M magnesium chloride solution for at least 0.5 min, leads to introduction of 1.7 to 2.3 at% magnesium at a distribution close to saturation on the titanium surface. The modified titanium surface sustained long term release of magnesium ions in acidic solution for more than 168 h. It was further demonstrated that the process of sustained release of magnesium ions is influenced by pH and can be triggered by lowering it from neutral to 3.