Biofilm formation on dental implant surfaces is a serious threat. Up to 50% of all implants show signs of irreversible tissue destruction. The aim of the present systematic review was to summarize the state of the art of strategies to functionalize antimicrobial dental implant surfaces. We searched the following electronic database: SCOPUS, MEDLINE and GOOGLE SCHOLAR and identified relevant controlled trials that evaluated the efficiency of new biomaterial strategies to modify dental implant surfaces, in such a way that biofilm formation was inhibited. The search yielded 2,990 potentially relevant publications. A total of 142 publications met the inclusion criteria. Analysis found that it may be concluded that silver-implanted surfaces, drug-loaded surfaces, surfaces with antimicrobial peptides, bioactive and biopassive polymer coatings as well as nanoscale or UV-activatable surfaces enhance antimicrobial activity compared to commercial pure titanium.
Novel fast-setting calcium silicate cement with fluoride (CSC) has been developed for potential applications in tooth crown. The aim of this study was to test the diametral tensile strength (DTS) of different CSC compositions in humid condition on day1, 28, and 180. We tested ‘bond CSC’ with 3.5% fluoride and no radiocontrast, ‘CSC’ with 3.5% fluoride and 10% radiocontrast, ‘ultrafast CSC’ with 3.5% fluoride and 20% radiocontrast, ‘high fluoride CSC’ with 15% fluoride and 25% radiocontrast, Biodentine, and MTA. We filled the cements after mixing to cylindrical molds. Specimens were stored in >95% humidity. DTS was measured at each time point. CSC compositions had statistically higher DTS compared to MTA and Biodentine on day1. Bond CSC showed higher DTS versus all cements, except CSC, at all time points. DTS of all cements, except Biodentine, significantly increased in humid condition on day28 and day180 compared to day1.
The mechanical properties —tensile strength, yield strength, elongation after fracture, and Vickers hardness— and alloy phases of the dental cast alloys Ti-6%Nb-4%Cu, Ti-18%Nb-2%Cu, and Ti-24%Nb-1%Cu were investigated. Ti-6%Nb-4%Cu consisted of a single α-phase, while Ti-18%Nb-2%Cu and Ti-24%Nb-1%Cu consisted of α- and β-phases. The tensile strengths, yield strengths, and hardnesses of these alloys were higher than those of Ti-5%Cu and Ti-30%Nb; however, their breaking elongations were smaller. These differences in the mechanical properties are attributable to solid-solution strengthening or to precipitation strengthening by the dual-phase (α+β) structure. Thus, Ti-Nb-Cu alloys are suitable for use in high-strength dental prostheses, such as implantretained superstructures and narrow-diameter implants.
The purpose of this study was to examine the translucency and low-temperature degradation of silica-doped experimental Y-TZP (Yttria-stabilized tetragonal zirconia polycrystal) containing almost no alumina. The experimental Y-TZP samples were sintered at either 1,450 or 1,500°C. The samples of commercially available translucent Y-TZP and conventional Y-TZP were used as controls. The contrast ratio (CR) and translucency parameter (TP) were obtained to compare the translucencies. In addition, the specimens were also subjected to an accelerated aging test. The results showed that the experimental Y-TZP sintered at 1,500°C and translucent Y-TZP exhibited almost the same level of translucency. During the accelerated aging test, the translucent Y-TZP underwent a substantial increase in monoclinic content, an index of degradation after the aging test. However, neither the experimental Y-TZP nor the conventional Y-TZP exhibited any appreciable change. It was concluded that the silica-doped Y-TZP will develop translucency and resistance to degradation when sintered at 1,500°C.
The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.
Although the demand for aesthetic restoration of primary molars has increased, the full-crown restorations using resin and the details of the wear characteristics of trimethylolpropane trimethacrylate (TMPT) filler containing resins for primary molars are not well understood. This study was conducted to determine whether new light-cured composite resin (Fantasista) and 4-META/MMATBB resin (Bondfill SB) are appropriate for full crown restoration of primary molars by evaluating their wear characteristics. Both resins products contain TMPT filler. The properties of the resins were evaluated through in vitro impacting-sliding wear tests; the wear properties of the opposing enamel specimens used in the tests were also studied. The properties of the resins were compared with those of Litefill, MetafilC, and Clearfil FII, which had been evaluated previously. Fantasista exhibited simple shape of wear that was suggestive of a higher wear resistance than that of Litefill. Fantasista caused the least damage to the antagonistic primary enamel.
To assess the retention force between primary and secondary PEEK crowns made by different fabrication methods. Primary crowns with different tapers (0°, 1°, and 2°) were fabricated and secondary crowns that were either milled from breCam BioHPP blanks, pressed from pellets (BioHPP Pellet) or granules (BioHPP Granulat) were produced. Each specimen was measured 20 times in a pulloff-test and results were analyzed using 2-/1-way ANOVA and linear regression analyses (p<0.05). Within 0° tapered crowns milled secondary crowns showed lower retention forces compared to pressed pellet crowns. Crowns with a 1° taper, however, showed no impact of the fabrication method on retention force. At a 2° taper, granular pressed crowns displayed lower values than their milled counterparts. Within the milled group, a 0° taper showed lower retention values than the higher tapers, whereas in the pressed groups, no impact of taper angle on retention force was found.
To overcome pain on injection, the dentist can apply a topical anesthetic spray. Despite the convenience, it is not easy to apply it locally. So, we developed an oral mucoadhesive bi-layer film containing an anesthetic. We used polyvinylpyrrolidone (PVP)/hydroxypropyl methylcellulose (HPMC) and HPMC-only layer as the drug-containing layer and ethyl cellulose (EC) as the backing layer. The lidocaine released was tested in vitro together with the adhesion time and cytotoxicity of the film. Mucosa permeability was tested in vivo. Statistical analysis was performed, with p at 0.05 taken to be significant. The lidocaine was released significantly faster in the PVP/HPMC than HPMC-only group and 80% of the drug was released within 1 min (p<0.05) and they attached at least 3 h. The test groups showed no toxicity and the drug effectively permeated the mucosa (p<0.05). We suggest this new mucoadhesive anesthetic may reduce dental phobia.
This study compared the dentin bond strength of a new universal adhesive with that of contemporary multi-step dentin adhesives. Six experimental groups were prepared according to the adhesives used and their application modes: Optibond FL (OB), Adper Single Bond Plus (SB), One-Step Plus (OS), Clearfil SE Bond (CS), All-Bond Universal using etch-and-rinse mode (ABE), and AllBond Universal using self-etch mode (ABS). Micro-tensile bond strength (µTBS) and failure mode were evaluated for each group. The bonded interface was analyzed using transmission electron microscopy (TEM). As a result, µTBS of 6 experimental groups was followed as: OB=ABE=SE=ABS>SB>OS group. TEM micrographs of ABE and ABS groups revealed a homogenous adhesive layer formation. In conclusion, a new universal adhesive can make reliable bond to dentin, regardless of the application mode.
This in situ study aimed to evaluate effects of waiting periods after erosive challenge before toothbrushing on enamel abrasion and nanoindentation hardness. Ten subjects wore intraoral appliances each with a set of 4 bovine enamel blocks. The enamel blocks were subjected to 2 cycles a day for 3 days as follows; intraoral exposure to form acquired pellicle and extraoral erosion followed by either 0, 3, 30 or 60 min intraoral exposure and then brushing, which was performed using an automatic brushing machine. Abrasive loss was assessed by white light interferometry. Nanoindentation was performed to calculate relative hardness. Abrasion and relative hardness were statistically analyzed by ANOVA. Abrasive loss was significantly less in groups exposed to saliva compared with 0 min (p<0.05); there was no significant difference between 30 and 60 min (p>0.05). Relative hardness was statistically higher after intraoral exposure, but no differences existed among any intraoral exposure periods (p>0.05).
The aim of this study was to evaluate the microhardness and surface roughness of composite resins immersed in alcoholic beverages. Three composite resins were used: Durafill (Heraeus Kulzer), Z250 (3M-ESPE) and Z350 XT (3M-ESPE). The inital surface roughness and microhardness were measured. The samples were divided into four groups (n=30): G1-artificial saliva; G2-beer; G3-vodka; G4-whisky. The samples were immersed in the beverages 3× a day for 15 min and 30 days. The surface roughness and microhardness assays were repeated after immersion period. The data were statistically analyzed by two-way ANOVA and Tukey-HSD test (p<0.05). Surface roughness increased for all composite resins immersed in beer and whisky. Microhardness of all groups decreased after immersion in alcoholic beverages. The effect of these beverages on dental composites is depended upon the chemical composition, immersion time, alcohol content and pH of solutions.
Strontium (Sr) ions were added to calcium- and phosphate-containing porous titanium oxide layers formed by micro-arc oxidation (MAO) of titanium (Ti) substrates to improve their osseointegration. An MC3T3-E1 preosteoblast was used to evaluate the effect of the incorporated Sr species on cell calcification. Similar surface microporous morphologies of the oxide layers were observed for all specimens produced by MAO, while the contents of the incorporated Sr ions increased with increasing Sr concentrations in MAO electrolytes. The calcium- and phosphate-containing porous layers promoted the cell alkaline phosphatase (ALP) activity, while cell calcification was promoted by the Sr addition. In particular, the ALP activity significantly increased after 10 days of culture, and larger areas of calcified deposits were observed for the specimens treated with MAO electrolytes containing 0.15 mol L−1 of Sr species. The effect of Sr addition on the calcification of the MAO-treated Ti oxide layers was established in this study.
The purposes of this study were to examine the shock absorption capability of addition-cured silicone denture relining materials and the bonding strength of addition-cured silicone denture relining materials and a commercial mouthguard material to determine its applicability to mouthguard adjustment. Two addition-cured silicone denture relining materials and eleven commercial mouthguard materials were selected as test materials. The impact test was applied by a free-falling steel ball. On the other hand, bonding strength was determined by a delamination test. After prepared surface treatments using acrylic resin on MG sheet surface, 2 types of addition-cured silicone denture relining materials were glued to MG surface. The peak intensity, the time to peak intensity from the onset of the transmitted force and bonding strength were statistically analyzed using ANOVA and Tukey’s honest significant difference post hoc test (p<0.05). These results suggest that the silicone denture relining materials could be clinically applicable as a mouthguard adjustment material.
The aims of this study were to evaluate the quality of canal filling using mineral trioxide aggregate (MTA) and gutta-percha (GP) in root canals, and to investigate the differences in the percentage of voids between mesial and distal canals by using microcomputed tomography. Twenty-two extracted human mandibular molars were instrumented using rotary files. Two teeth without canal fillings served as negative controls, and the other teeth were obturated with either ProRoot® MTA or gutta-percha and AH Plus® sealer. Obturated teeth were scanned with microcomputed tomography, and the percentage of voids (V%) was calculated. These specimens were also examined under a scanning electron microscope. The MTA group showed a significantly higher V% than the GP groups (p<0.05). The mesial canal groups showed significantly higher V% than did the distal canal groups (p<0.05). In orthograde filling, MTA exhibited significantly lower filling quality than did GP.
Application of hydroxyapatite (HAp) nanoparticles to repair damaged enamel has attracted recent attention. In this study, HAp nanoparticles with various morphologies (spherical, short-rod, long-rod and fiber morphologies) were synthesized via chemical precipitation methods without the addition of template molecules, and the adsorption/desorption behaviors of a cationic antibacterial agent, cetylpyridinium chloride (CPC), on the HAp nanoparticles were evaluated. The adsorption of CPC on each HAp nanoparticle showed Langmuir-type adsorption, and the short-rod/long-rod HAp nanoparticles showed thermodynamically more stable adsorption of CPC than that with the spherical/fiber HAp nanoparticles. The desorption rate of CPC from the short-rod/long-rod HAp nanoparticles was slower than that of the spherical/fiber HAp nanoparticles. The HAp nanoparticles with different CPC release profiles presented here have potential applications as nanoparticulate enamel repair agents with antibacterial properties.
This study investigates the anti-bacterial property of Ti-Cu sintered alloys against Porphyromonas gingivalis. The anti-anaerobic property of Ti-Cu sintered alloys against P. gingivalis was investigated by antibacterial activity test, DNA measurement, DAPI staining and morphology observation. The antibacterial rates of the Ti-5Cu against P. gingivalis after 18 and 24 h incubation were 36.04 and 54.39%, and those of Ti-10Cu were 68.69 and 75.39%, which were lower than their anti-aerobic abilities. The concentration of P. gingivalis DNA gradually decreased with the increasing Cu content, which was nearly 50% after 24 h incubation on Ti-10Cu. SEM results showed that the shape of P. gingivalis changed and the bacteria broke apart with the addition of Cu and the extension of the culture time. Ti-Cu sintered alloys could not only kill anaerobic bacteria but also reduce the activity of the survived bacteria. The anti-anaerobic mechanism was thought to be in associated with the Cu ion released from Ti-Cu alloy.
This study evaluated the effect of surface pretreatments on resin composite bonding to polyetheretherketone (PEEK). Four groups of surface pretreatment (no pretreatment, etched with 98% sulfuric acid, etched with piranha solution and sandblasting with 50 µm alumina) were performed on PEEK. Surface roughness, Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis were examined. Shear bond strength (SBS) and interface characteristics were also evaluated after the specimens were bonded with resin materials. Two-way ANOVA analysis revealed significance on two main effects and interactions. Tukey’s multiple comparisons test showed that the SBS of resin composite on PEEK were the highest in the group etched with 98% sulfuric acid and bonded with Heliobond® (p<0.05). All pretreatments produced similar spectra of FTIR patterns. SEM demonstrated porosities and pitting from chemical etching, which suggested a significant influence on the adhesion between PEEK and resin materials.
This study aimed to investigate the effect of enamel margin configuration on color change of resin composite restoration. Enamel disks of 1.0 mm-thick were sliced from sixty bovine anterior teeth and divided into three groups by margin configuration (non-bevel, 45-degree bevel and 45-degree reverse-bevel). The color measurements (L*C*h* values) at the restored bovine enamel disk with resin composite (Estelite Asteria, Estelite Pro, Kalore, Clearfil Majesty) were performed using a digital camera with CIE XYZ color gamut (RC500). All the resin composite restorations with non-beveled and beveled cavities significantly increased L* values compared with the control composite disks (p<0.05). The bevel preparation increased L* values toward the enamel-composite border with gentle inclination, while the reverse-bevel preparation was significantly lower L* values at the enamel-composite border than the non-bevel preparation (p<0.05). Enamel margin configuration affected color shifting of resin composite restoration and color adjustment of the border.
Dentin bonding durability of recently introduced dental adhesives: Clearfil SE Bond 2 (SE2), Optibond XTR (XTR), and Scotchbond Universal (SBU) was investigated using Weibull analysis as well as analysis of the micromorphological features of the acid-base resistant zone (ABRZ) created for the adhesives. The bonding procedures of SBU were divided into three subgroups: self-etch (SBS), phosphoric acid (PA) etching on moist (SBM) or dry dentin (SBD). All groups were thermocycled for 0, 5,000 and 10,000 cycles followed by microtensile bond strength testing. Acid-base challenge was undertaken before SEM and TEM observations of the adhesive interface. The etch-and-rinse method with SBU (SBM and SBD) created inferior interfaces on the dentin surface which resulted in reduced bond durability. ABRZ formation was detected with the self-etch adhesive systems; SE2, XTR and SBS. In the PA etching protocols of SBM and SBD, a thick hybrid layer but no ABRZ was detected, which might affect dentin bond durability.
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