Correlations of FCGR2A 131R/H and FCGR3A 158V/F Polymorphisms with the Susceptibility of Peri-implantitis in Chinese Han Population.

The purpose of the study is to investigate the relationship of peri-implantitis (PI) with FCGR2A and FCGR3A gene polymorphisms. One hundred and forty-four patients with PI and 136 patients without PI infection were selected. Gingival crevicular fluid samples were collected from the two groups. The FCGR2A and FCGR3A polymorphism in the two groups were measured. All volunteers were evaluated for periodontal status. The effect of polymorphisms on PI susceptibility was investigated by chi-square analysis and logistic regression. The frequency of FCGR2A rs1801274 GG genotype of PI group was higher than that of the control group, while the GA and AA genotype carriers were less in PI group. After adjusting for other clinical indicators, rs1801274 GA genotype, AA genotype, and the A allele were still negatively correlated with the onset of PI. FCGR3A rs396991 polymorphism was not associated with PI. FCGR2A rs1801274 polymorphism was significantly associated with PI in the Chinese Han population, and GG genotype might be a genetic risk factor for PI.

In vitro comparison of bonding to zirconia- or glass- based ceramics between flowable resin composites and composite resin cements.

PURPOSE: To evaluate and compare the bonding of flowable resin composites and light-cured resin cements to dental ceramics. METHODS: Grit-blasted zirconia plates were primed with MDP-containing adhesive. Lithium disilicate glasses plates were etched with HF and primed with silane. Two flowable resin composites with high (CM: 75 wt%/62 vol%) and low (BF: 67.3 wt%/47 vol%) filler contents, and two resin cements, again with high (C: 72 wt%/69 vol%) and low (R: 66 wt%/47 vol%) filler contents, were bonded to both types of pretreated ceramics. Shear bond strength (SBS) was measured after 24 hours water storage or 10,000 times thermocycling between 5 and 55°C. The viscosities and film thicknesses of the four resin-based luting agents (RBLAs) were also explored by rotational rheometer and metallurgical microscope severally. RESULTS: Different RBLAs provided statistically different SBS values, with the high-filler specimens exhibiting higher SBS values than the low-filler specimens. The viscosities decreased in the order C > R > BF > CM. The film thicknesses for the BF and C groups were higher than those of the CM and R groups. CLINICAL SIGNIFICANCE: This study provides evidence that flowable resin composites with high filler contents and low viscosities may serve as an alternative to light-cured resin cements for luting zirconia or lithium disilicate glass. This expands the range of light-cured luting agents available for bonding of veneers or other thin restorations, which is of great benefit to clinical practice.

Effects of Tribochemical Silica Coating and Alumina-Particle Air Abrasion on 3Y-TZP and 5Y-TZP: Evaluation of Surface Hardness, Roughness, Bonding, and Phase Transformation.

PURPOSE: To determine and compare the effects of tribochemical silica coating and alumina-particle air abrasion on 3 mol% and 5 mol% yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). MATERIALS AND METHODS: Two different 3Y-TZP samples (Lava Plus, 3M Oral Care; Ceramill Zolid, Amann Girrbach) and one 5Y-TZP sample (Katana Zirconia UTML, Kuraray Noritake) were prepared and treated with alumina-particle air abrasion and a 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing self-adhesive composite cement or with tribochemical silica coating followed by silanization (n = 30). Resin columns were cemented onto the treated ceramic surfaces to form specimens. After 24-h water storage or aging with 10,000 thermocycles plus 60-day water storage, shear bond strength (SBS) testing was conducted. Surface roughness, surface Vickers hardness, and crystallographic phase analyses were also performed. RESULTS: The SBS of tribochemically silica-coated 5Y-TZP before and after aging were 13.8 ± 1.4 and 13.2 ± 1.5 MPa, resp., for Lava Plus (3Y-TZP) 14.4 ± 1.4 and 13.9 ± 1.6 MPa, respectively, and for Ceramill Zolid (3Y-TZP) 14.8 ± 1.1 and 13.9 ± 1.5 MPa, respectively. There was no statistical difference between tribochemical silica coating and alumina air abrasion treatments (p = 0.21) on the bonding performance (SBS) of the 3Y-TZPs and 5Y-TZP (p = 0.25) before and after aging (p = 0.50). After alumina air abrasion, 5Y-TZP showed higher surface roughness (Ra = 1.7 ± 0.1) than did the 3Y-TZPs (Ra = 1.2 ± 0.1 for Lava Plus; Ra = 1.2 ± 0.1 for Ceramill Zolid), while the Vickers hardness was similar among the three materials (p = 0.70). Monoclinic zirconia was not detected in 5Y-TZP irrespective of treatment, with the zirconia being mainly cubic phase. However, the 3Y-TZPs were mainly tetragonal phase with some monoclinic zirconia; the latter increased after being alumina-particle air abraded. CONCLUSION: The bond strength to 5Y-TZP is similar to those of the 3Y-TZPs under the same bonding strategies. Durable bonding can be achieved both by alumina air abrasion combined with a 10-MDP-containing self-adhesive composite cement and by tribochemical silica coating followed by silanization for both the 3Y-TZPs and 5Y-TZP.

Effects of hydrothermal aging, thermal cycling, and water storage on the mechanical properties of a machinable resin-based composite containing nano-zirconia fillers.

OBJECTIVES: This study aimed to investigate the effects of hydrothermal aging, thermal cycling, and water storage on the mechanical properties of a machinable resin-based composite containing nano-zirconia fillers. MATERIALS AND METHODS: A machinable resin-based composite containing nano-zirconia fillers (Lava Ultimate, LU) and a resin-based composite with a similar resin matrix-to-filler ratio but without zirconia fillers (Tetric N-Ceram, TNC) were prepared into bars and assigned into four groups based on the type of aging treatment (hydrothermal aging, thermal cycling, water storage, or no aging). The phase transformations of the zirconia fillers in LU after aging were evaluated by X-ray diffraction. The flexural strength, Weibull modulus, flexural modulus, and Vickers hardness of each group were investigated. The fracture surface morphologies of both resin-based composites before and after aging were observed by a scanning electron microscopy (SEM). RESULTS: Only Tetragonal zirconia was detected in the LU samples. Both before and after aging, the flexural strength, flexural modulus, and Vickers hardness values of LU were significantly higher than those of TNC (p < 0.05) with the exception of the flexural modulus of LU, which showed no difference with that of TNC after water storage (p = 0.68). Hydrothermal aging, thermal cycling, and water storage had no significant effects on the surface Vickers hardnesses of LU or TNC (p > 0.05). Hydrothermal aging significantly improved the flexural strength of LU (p = 0.00). Thermal cycling (p = 0.00) and water storage (p = 0.00) significantly decreased the flexural strength of LU. The flexural strength of TNC was not decreased by hydrothermal aging (p = 0.82) or water storage (p = 0.36), while it was decreased by thermal cycling (p = 0.00). The hydrothermal aging group of LU exhibited the highest Weibull modulus. CONCLUSIONS: The machinable resin-based composite containing nano-zirconia fillers provides superior flexural strength, flexural modulus, and Vickers hardness compared to the direct-filling resin-based composite with a similar resin matrix-to-filler ratio, although it fails to provide better aging resistance.

Bond durability when applying phosphate ester monomer-containing primers vs. self-adhesive resin cements to zirconia: Evaluation after different aging conditions.

PURPOSE: This study aimed to evaluate bond durability when applying 2 phosphate ester monomer-containing self-adhesive resin cements alone, versus a combination of phosphate ester monomer-containing primer conditioning plus 2 conventional resin cements requiring primers, to zirconia after different artificial aging methods. METHODS: We cemented air-abraded zirconia plates to composite resin cylinders with self-adhesive resin cements (MS; RU) alone or cemented them with traditional resin cements (ZRV; ZVN) after pre-conditioning with a zirconia primer. A shear bond strength (SBS) test were performed after subjecting them to 19 different aging conditions (n = 15) comprising 30,000× thermocycles, air storage at room temperature (RT), water storage at RT, or at 37 °C for 24 h, 1 week, 1, 3, 6, and 12 months. Zirconia powders mixed with zirconia primer or 2 self-adhesive resin cements were characterized by X-ray photoelectron spectroscopy. RESULTS: Groups MS and ZVN obtained the highest SBS after all of aging methods. SBS after 6 months of storage was similar to SBS after 24 h of storage, while both were higher than SBS after 1 year of storage. Water storage at 37 °C provided higher SBS than RT water storage did. We detected a Zr-O-P bond in both self-adhesive resin cement/zirconia powder mixtures. CONCLUSIONS: Application of self-adhesive resin cements alone could be an alternative to pre-conditioning with a zirconia primer followed by the application of conventional resin cements. Formation of Zr-O-P bonds contributed to the bonding improvement of self-adhesive resin cements. Different aging conditions affected SBS values.

Choice of resin cement shades for a high-translucency zirconia product to mask dark, discolored or metal substrates.

PURPOSE: The aim was to study the masking ability of high-translucency monolithic zirconia and provide guidance in selecting resin luting cements in order to mask discolored substrates. MATERIALS AND METHODS: 160 high-translucency zirconia specimens were divided into 32 groups depending on their thickness and shades. Using five shades of try-in paste, the specimens were luted onto the sub strates (Co-Cr, precious-metal, opaque porcelain-sintered Co-Cr, opaque porcelain-sintered precious-metal, and 5M3-shade zirconia). All CIELAB color parameters were measured and statistically analyzed. RESULTS: Zirconia shade and thickness and try-in paste shade affected CIELAB color parameters (P=.000) in different substrates groups, and there were interactions among these factors (P=.000). All five try-in paste shades can be chosen to achieve ΔE values of zirconia with 1.2 - 1.5 mm for masking dark-tooth-like 5M3-shade and zirconia with 1.5 mm for masking precious-metal groups < 2.6. Only suitable try-in paste shades were used, can ΔE values that less than 2.6 be achieved when applied translucent monolithic zirconia with 0.7-1.0 mm for masking dark-tooth-like 5M3-shade and zirconia with 0.7 - 1.2 mm for masking precious-metal groups. CONCLUSION: Choosing suitable resin cement shades is necessary for high-translucency monolithic zirconia to achieve ideal masking ability (ΔE < 2.6) on the dark-tooth.

Effectiveness of pre-silanization in improving bond performance of universal adhesives or self-adhesive resin cements to silica-based ceramics: Chemical and in vitro evidences.

OBJECTIVES: To examine effectiveness of pre-silanization in improving bond performance of multipurpose products such as universal adhesives or self-adhesive resin cements to silica-based ceramics. METHODS: The present study investigated reactions between silanol groups of γ-methacryloxypropyltrimethoxysilane (γ-MPS) and silica, dehydration self-condensation of γ-MPS, and condensation polymerization between γ-MPS and 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) by using thermodynamic calculations. Shear bond strength (SBS) tests were used to evaluate the influence of pre-silanization on resin bonding when a silane-containing universal adhesive, a silane-unknown universal adhesive, or two self-adhesive resin cements were applied for bonding lithium disilicate to resin. In addition, reactions between silane and lithium disilicate were analyzed using X-ray photoelectric spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). RESULTS: Acquired thermodynamic data indicated formation of siloxane between γ-MPS and silica. However, self-condensation of γ-MPS and reaction between γ-MPS and 10-MDP consumed the silanol. Pre-silanization enhanced SBS for self-adhesive resin cements or universal adhesives when applied for bonding silica-based ceramics. Thermocycling and aging decreased SBS in most groups. XPS and FTIR supported formation of siloxane between the employed silane coupling agent and two universal adhesives and lithium disilicate. SIGNIFICANCE: Pre-silanization is beneficial in further enhancing bond performance of universal adhesives or self-adhesive resin cements to silica-based ceramics.

Shear bond strength of zirconia to resin: The effects of specimen preparation and loading procedure.

PURPOSE: Shear bond strength (SBS) test is the most commonly used method for evaluating resin bond strength of zirconia, but SBS results vary among different studies even when evaluating the same bonding strategy. The purpose of this study was to promote standardization of the SBS test in evaluating zirconia ceramic bonding and to investigate factors that may affect the SBS value of a zirconia/resin cement/composite resin bonding specimen. MATERIALS AND METHODS: The zirconia/resin cement/composite resin bonding specimens were used to simulate loading with a shear force by the three-dimensional finite element (3D FE) modeling, in which stress distribution under uniform/non-uniform load, and different resin cement thickness and different elastic modulus of resin composite were analyzed. In vitro SBS test was also performed to validate the results of 3D FE analysis. RESULTS: The loading flat width was an important affecting factor. 3D FE analysis also showed that differences in resin cement layer thickness and resin composite would lead to the variations of stress accumulation area. The SBS test result showed that the load for preparing a SBS specimen is negatively correlated with the resin cement thickness and positively correlated with SBS values. CONCLUSION: When preparing a SBS specimen for evaluating bond performance, the load flat width, the load applied during cementation, and the different composite resins used affect the SBS results and therefore should be standardized.

Effect of tribochemical silica coating or multipurpose products on bonding performance of a CAD/CAM resin-based material.

OBJECTIVES: Nanocomposite ceramics have been widely used in clinical practice; however, a standard, recommended bonding protocol has not been determined yet. The present study aimed to evaluate application of tribochemical silica coating or multipurpose products on bonding performance of a CAD/CAM resin-based material (known as nanocomposite ceramic). MATERIALS AND METHODS: Nanocomposite ceramic specimens were fabricated and assigned into 11 groups to build bonded specimens (n = 15) according to surface treatments (none; air particle abrasion with 50-µm alumina followed by application of a silane coupling agent or a universal adhesive; tribochemical silica coating followed by application of a silane coupling agent or a universal adhesive) and resin luting cements (conventional resin cement, RelyX Veneer; self-adhesive resin cement RelyX Unicem) used. Micro-shear bond strength (µ-SBS) was measured after 24-h water storage or ageing with 10,000 thermocycles plus additional 90-d water storage. Surface roughness after alumina air abrasion and tribochemical silica coating were determined using a profilometer. Surface morphology and element variation were observed by using a scanning electron microscope (SEM)/energy dispersion spectrum (EDS). X-ray photoelectron spectroscopy (XPS) was used to characterize nanocomposite ceramic powders conditioned with silane coupling agent or the universal adhesive used in the µ-SBS test. The nanocomposite ceramic plates received alumina air abrasion, tribochemical silica coating, or without, were determined using X-ray diffraction (XRD). RESULTS: Nanocomposite ceramic treated with alumina air abrasion achieved the highest surface roughness, followed by those treated with tribochemical silica coating. Newly formed Si-O-Si bonds on the nanocomposite ceramic surface were detected by XPS after treatment with silane coupling agent or universal adhesive, and a Zr-O-P bond was detected after treating with universal adhesive. µ-SBS was significantly affected by bond strategies and ageing. Ageing by thermocycling and water storage significantly decreased µ-SBS. µ-SBS values derived by use of a universal adhesive or self-adhesive resin cement alone were no lower than the values derived by use of a silane coupling agent alone. Pre-silanization further enhanced the bonding improvement of universal adhesive or self-adhesive resin cement. However, tribochemical silica coating failed to provide higher µ-SBS compared with alumina air abrasion. XRD detected no monoclinic zirconia phase after alumina air abrasion or tribochemical silica coating, suggesting that these two roughening methods did not lead to phase transformation of zirconia fillers. CONCLUSIONS: Combination of presilanization and universal adhesives improve resin bonding of nanocomposite ceramics. Tribochemical silica coating is not superior to alumina air abrasion for pretreated nanocomposite ceramics.

Durability of Resin Bonding to Zirconia Using Products Containing 10-Methacryloyloxydecyl Dihydrogen Phosphate.

PURPOSE: To examine the durability of composite bonding to zirconia after artificial aging using different products containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP). MATERIALS AND METHODS: Conditioning methods were: none (control [Ctr]; Clearfil SA Luting [CSL]; Panavia SA Luting Plus [PSLP]), MDP-containing zirconia primers (Z-Prime Plus [ZP]; Clearfil Ceramic Primer [CCP]), and MDP-containing universal adhesives (Single Bond Universal [SBU]; Clearfil Universal Bond [CUB]). For the Ctr, ZP, CCP, SBU, and CUB groups, the Y-TZP plates were bonded with MDP-free composite cement. For the remaining two groups, each Y-TZP plate was bonded with one of MDP-containing self-adhesive composite cements (CSL; PSLP). The specimens in each group (n = 30) were divided into two subgroups, with one subgroup of samples subjected to 24-h water storage and the other to aging through 30,000 thermocycles plus 180-day water storage. Shear bond strength (SBS) was measured. For each conditioning method, inductively coupled plasma-mass spectrometry (ICP-MS) was used to quantify the release of phosphorus, and microleakage was evaluated through a methylene-blue dyeing technique. RESULTS: The Ctr group exhibited the lowest SBS regardless of aging. Thermocycling and water storage significantly decreased the SBS in all groups, with the exception of the groups with the MDP-containing zirconia primers. Groups with MDP-containing universal adhesives and self-adhesive composite cements presented brand-dependent higher SBS, even after aging. ICP-MS detected phosphorus release from all of the MDP-containing products. Microleakage was identified at the interfaces of all bonded specimens, with the highest rate detected in the Ctr group. CONCLUSION: MDP-containing primers, universal adhesives, and composite cements create bonds to zirconia with acceptable strength after long-term aging.

Effects of multiple firings on mechanical properties and resin bonding of lithium disilicate glass-ceramic.

OBJECTIVES: This study aimed to evaluate the effects of different firing cycles on surface hardness, fracture toughness, and roughness of lithium disilicate glass-ceramic, as well as their bond strength to resin. MATERIALS AND METHODS: A total of 320 polished lithium disilicate glass-ceramic plates were assigned to four main groups (n = 60) to receive one, two, three, or four firing cycles, respectively. Ceramic plates of the four groups were conditioned with HF acid followed by silanization. The pre-treated ceramic plates were cemented with composite resin cylinders using conventional or self-adhesive resin cements to build bonded specimens, and submitted to shear-bond-strength (SBS) testing after water storage for 24 h or 3 mo at 37 °C. The ceramic received different firing cycles after polishing or HF etching was observed using a scanning electron microscope, and their surface roughnesses were determined by a profilometer. The surface Vickers hardness, fracture toughness, and related Weibull analysis results of the polished ceramics after undergoing different firing-cycle times were compared. RESULTS: One sintering significantly increased fracture toughness of lithium disilicate glass-ceramic; however, multiple firing cycles failed to increase it further. Weibull analysis revealed a significant difference in terms of structural reliability among the specimens receiving 0-4 firing cycles. Specimens that received no firing cycle showed the highest surface hardness. Multiple firing cycles had no significant influence on the surface Vickers hardness and surface roughness. HF etching increased surface roughness, and the roughened surface improved the resin SBS of lithium disilicate glass-ceramic. Multiple firing cycles had no significant effect on surface roughness. Furthermore, multiple firing cycles and 3-mo water storage had no significant effect on the SBS. CONCLUSIONS: The mechanical properties of lithium disilicate glass-ceramics would be partially affected by multiple firing cycles, while their resin bonding would not be.

[Effects of nano-zirconium hydroxide coating on resin bonding of 10-methacryloxy decyldihydrogen phosphate-conditioned zirconia].

OBJECTIVE: This study evaluated the influence of alkaline coating of nano-zirconium hydroxide on resin bonding of 10-methacryloxy decyldihydrogen phosphate (MDP)-conditioned zirconia. METHODS: A total of 140 yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) plates were prepared and sandblasted with alumina particles, and then subjected to different surface treatment. Resin bonding specimens were prepared with a MDP-free resin cement and tested for shear bond strength (SBS). X-ray photoelectron spectroscopy (XPS) was used to investigate the formation of chemical bond on the surface of Y-TZP treated successively with nano-zirconium hydroxide coating and MDP containing primer. RESULTS: The two alkaline coatings increased the 24 h SBS compared to control groups, and groups using nano-zirconium hydroxide coating yielded higher SBS. After thermocycling, no statistical difference was observed between groups, but SBS decreased significantly compared to the 24 h SBS (P<0.05). XPS analysis detected -OH bond on the surface of Y-TZP treated with nano-zirconium hydroxide coating, and -P-O-Zr bond was detected on the surface of Y-TZP treated with nano-zirconium hydroxide coating and MDP-containing primer. CONCLUSIONS: Alkaline coatings improved the bonding of resin to zirconia conditioned with MDP-containing primers.