Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 21
1.
BMC Oral Health ; 24(1): 359, 2024 Mar 21.
Article En | MEDLINE | ID: mdl-38509530

This systematic review explores the accuracy of computerized guided implant placement including computer-aided static, dynamic, and robot-assisted surgery. An electronic search up to February 28, 2023, was conducted using the PubMed, Embase, and Scopus databases using the search terms "surgery", "computer-assisted", "dynamic computer-assisted", "robotic surgical procedures", and "dental implants". The outcome variables were discrepancies including the implant's 3D-coronal, -apical and -angular deviations. Articles were selectively retrieved according to the inclusion and exclusion criteria, and the data were quantitatively meta-analysed to verify the study outcomes. Sixty-seven articles were finally identified and included for analysis. The accuracy comparison revealed an overall mean deviation at the entry point of 1.11 mm (95% CI: 1.02-1.19), and 1.40 mm (95% CI: 1.31-1.49) at the apex, and the angulation was 3.51˚ (95% CI: 3.27-3.75). Amongst computerized guided implant placements, the robotic system tended to show the lowest deviation (0.81 mm in coronal deviation, 0.77 mm in apical deviation, and 1.71˚ in angular deviation). No significant differences were found between the arch type and flap operation in cases of dynamic navigation. The fully-guided protocol demonstrated a significantly higher level of accuracy compared to the pilot-guided protocol, but did not show any significant difference when compared to the partially guided protocol. The use of computerized technology clinically affirms that operators can accurately place implants in three directions. Several studies agree that a fully guided protocol is the gold standard in clinical practice.


Dental Implants , Robotic Surgical Procedures , Surgery, Computer-Assisted , Humans , Dental Implantation, Endosseous/methods , Computers , Computer-Aided Design , Cone-Beam Computed Tomography , Imaging, Three-Dimensional
2.
J Clin Med ; 13(3)2024 Feb 02.
Article En | MEDLINE | ID: mdl-38337580

This study aimed to evaluate the effect of customized healing abutments compared to prefabricated healing abutments in immediate implant sites. Twelve patients requiring single immediate implant placement were divided into two groups: a prefabricated group received prefabricated titanium healing abutments, and a customized group received a polyetheretherketone (PEEK) customized healing abutments fabricated based on the individuals' digital impressions. Outcomes, including peri-implant horizontal and vertical soft tissue alteration, bone level change, volume change, pain score, and pink esthetic score (PES) change, were evaluated at the 1-, 4-, and 6-month follow-ups compared to pre-extraction teeth. At the 1- and 4-month follow-ups, the customized group had a significantly lower buccal volume variation (BVv). At the 6-month follow-up, neither group showed any significant difference in the marginal bone change; however, the customized group had a significantly lower PES change and a lower pain score. In the anterior and premolar regions, the customized group showed the preservation of peri-implant buccal horizontal soft tissue and buccal volume, while in the molar regions, the preservation of papilla height and midfacial height was observed. The morphology of the customized healing abutment demonstrated a better trend in preservation of peri-implant soft tissue, esthetic outcomes, and lower patient discomfort in immediate implant sites.

3.
J Clin Med ; 12(21)2023 Nov 03.
Article En | MEDLINE | ID: mdl-37959389

Titanium has been the material of choice for dental implant fixtures due to its exceptional qualities, such as its excellent balance of rigidity and stiffness. Since zirconia is a soft-tissue-friendly material and caters to esthetic demands, it is an alternative to titanium for use in implants. Nevertheless, bone density plays a vital role in determining the material and design of implants. Compromised bone density leads to both early and late implant failures due to a lack of implant stability. Therefore, this narrative review aims to investigate the influence of implant material/design and surgical technique on bone density from both biomechanical and biological standpoints. Relevant articles were included for analysis. Dental implant materials can be fabricated from titanium, zirconia, and PEEK. In terms of mechanical and biological aspects, titanium is still the gold standard for dental implant materials. Additionally, the macro- and microgeometry of dental implants play a role in determining and planning the appropriate treatment because it can enhance the mechanical stress transmitted to the bone tissue. Under low-density conditions, a conical titanium implant design, longer length, large diameter, reverse buttress with self-tapping, small thread pitch, and deep thread depth are recommended. Implant material, implant design, surgical techniques, and bone density are pivotal factors affecting the success rates of dental implant placement in low-density bone. Further study is required to find the optimal implant material for a clinical setting's bone state.

4.
Drug Discov Ther ; 17(4): 238-247, 2023 Sep 15.
Article En | MEDLINE | ID: mdl-37612046

Synthesis of nanoparticles using natural organic substances has attracted more attention due to avoiding inorganic toxicity. This work aimed to synthesize copper oxide nanoparticles (CuONPs) using Caesalpinia sappan heartwood extract as a reducing agent. The effects of pH of synthesis reaction were investigated. The obtained CuONPs were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Their particle size, size distribution, and zeta potential were determined using photon correlation spectrophotometry. Candida albicans is a major cause of chronic fungal infections due to its biofilms leading to severe drug resistance problems. In this study, in vitro antifungal and antibiofilm activities as well as killing kinetics of the synthesized CuONPs against C. albicans were investigated. Additionally, fungal biofilm was observed by using confocal laser scanning microscopy. The results showed that the pH of the synthesis reaction played an important role in the physicochemical properties and antifungal activities of the obtained CuONPs. CuONPs synthesized at pH 10 and 12 showed the relatively small and narrow size distribution with high negative zeta potential and time-dependent killing kinetics. Confocal laser scanning microscopy confirms obvious fungal biofilm reduction and increased fungal cell death after exposure to CuONPs. These findings suggest the optimal pH of CuONPs synthesis using C. sappan extract as a reducing agent. The results on antifungal and antibiofilm activities indicate that the obtained CuONPs can be a promising agent for treating fungal infection.


Caesalpinia , Nanoparticles , Antifungal Agents/pharmacology , Candida albicans , Copper , Reducing Agents , Biofilms , Excipients , Plant Extracts/pharmacology , Oxides
5.
J Funct Biomater ; 13(4)2022 Dec 10.
Article En | MEDLINE | ID: mdl-36547551

Customized healing abutments have been introduced in clinical practice along with implant surgery to preserve or create natural-appearing hard and soft tissue around the implant. This provides the benefits of reducing the overall treatment time by eliminating the second stage and reducing the elapsed time of the fabrication of the final prostheses. This article aims to review the types and properties of materials used for the fabrication of customized healing abutments and their clinical applications. Articles published in English on customized healing abutments were searched in Google Scholar, PubMed/MEDLINE, ScienceDirect, and the Scopus databases up to August 2022. The relevant articles were selected and included in this literature review. Customized healing abutments can be fabricated from materials available for dental implants, including PEEK, PMMA, zirconia, resin composite, and titanium. All the materials can be used following both immediate and delayed implant placement. Each material provides different mechanical and biological properties that influence the peri-implant tissues. In conclusion, the studies have demonstrated promising outcomes for all the materials. However, further investigation comparing the effects of each material on peri-implant soft and hard tissues is required.

6.
J Funct Biomater ; 13(2)2022 Mar 22.
Article En | MEDLINE | ID: mdl-35466215

Polyetheretherketone (PEEK) has become a useful polymeric biomaterial due to its superior properties and has been increasingly used in dentistry, especially in prosthetic dentistry and dental implantology. Promising applications of PEEK in dentistry are dental implants, temporary abutment, implant-supported provisional crowns, fixed prosthesis, removable denture framework, and finger prosthesis. PEEK as a long-term provisional implant restoration has not been studied much. Hence, this review article aims to review PEEK as a long-term provisional implant restoration for applications focusing on implant dentistry. Articles published in English on PEEK biomaterial for long-term provisional implant restoration were searched in Google Scholar, ScienceDirect, PubMed/MEDLINE, and Scopus. Then, relevant articles were selected and included in this literature review. PEEK presents suitable properties for various implant components in implant dentistry, including temporary and long-term provisional restorations. The modifications of PEEK result in wider applications in clinical dentistry. The PEEK reinforced by 30-50% carbon fibers can be a suitable material for the various implant components in dentistry.

7.
Antibiotics (Basel) ; 10(4)2021 Apr 15.
Article En | MEDLINE | ID: mdl-33920823

Candida albicans is a common overgrowth in people wearing dentures. Long-term use of antifungal chemicals carries a risk of toxic side effects. This study focused on the edible Piper betle extract because of its safety. The broth dilution method was applied for antifungal determination of the ethyl acetate fractionated extract (fEA) and fEA-loaded polymeric micelles (PMF). The PMF was prepared by thin-film hydration using poloxamer 407 as a polymer base. The results found that the weight ratio of fEA to polymer is the main factor to obtain PMF system as a clear solution, nanoparticle sizes, narrow size distribution, negative zeta potential, and high entrapment efficiency. The activity of PMF against C. albicans is significantly higher than fEA alone, with a minimum fungicidal concentration of 1.5 mg/mL. PMF from 1:3 ratio of fEA to polymer is used to develop a denture-soaking solution contained 1.5 mg fEA/mL (PMFS). A clinical study on dentures of 15 volunteers demonstrated an 86.1 ± 9.2% reduction of C. albicans after soaking the dentures in PMFS daily for 14 days. Interestingly, PMFS did not change the hardness and roughness of the denture base resins. The developed PMFS may serve as a potential natural denture-soaking solution against candidiasis in denture wearers.

8.
Pharmaceutics ; 13(4)2021 Mar 26.
Article En | MEDLINE | ID: mdl-33810448

Carbamide peroxide (CP), a tooth whitening agent, is chemically unstable. The present study explores stability enhancement of CP by loading in a nanofibrous film (CP-F) composed of polyvinyl alcohol/polyvinylpyrrolidone/silica mixture, using an electrospinning technique. Kept at a temperature range of 60-80 °C for 6 h, CP in CP-F showed significantly higher stability than that in a polymer solution and in water, respectively. Degradation of CP in CP-F could be described by the first order kinetics with the predicted half-life by the Arrhenius equation of approximately 6.52 years. Physicochemical properties of CP-F after long-term storage for 12 months at different temperatures and relative humidity (RH) were investigated using scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy. It was found that high temperature and high humidity (45 °C/75% RH) could enhance water absorption and destruction of the nanofibrous structure of CP-F. Interestingly, kept at 25 °C/30% RH, the nanofibrous structure of CP-F was not damaged, and exhibited no water absorption. Moreover, the remaining CP, the mechanical properties, and the adhesive properties of CP-F were not significantly changed in this storage condition. It is concluded that the developed CP-F and a suitable storage condition can significantly improve CP stability.

9.
Pharmaceuticals (Basel) ; 14(2)2021 Feb 07.
Article En | MEDLINE | ID: mdl-33562244

Burst release of carbamide peroxide (CP) from traditional hydrogels causes severe inflammation to periodontal tissues. The present study explores the development of a novel CP nanoemulgel (CP-NG), an oil-in-water nanoemulsion-based gel in which CP was loaded with a view to controlling CP release. CP solid dispersions were prepared, using white soft paraffin or polyvinylpyrrolidone-white soft paraffin mixture as a carrier, prior to formulating nanoemulsions. It was found that carrier type and the ratio of CP to carrier affected drug crystallinity. Nanoemulsions formulated from the optimized CP solid dispersions were used to prepare CP-NG. It was found that the ratio of drug to carrier in CP solid dispersions affected the particle size and zeta potential of the nanoemulsions as well as drug release behavior and tooth bleaching efficacy of CP-NG. Drug release from CP-NG followed a first-order kinetic reaction and the release mechanism was an anomalous transport. Drug release rate decreased with an increase in solid dispersion carriers. CP-NG obtained from the solid dispersion with a 1:1 ratio of CP to the polymer mixture is suitable for sustaining drug release with high tooth bleaching efficacy and without reduction of enamel microhardness. The developed CP-NG is a promising potential tooth bleaching formulation.

10.
Pharmaceutics ; 13(2)2021 Jan 27.
Article En | MEDLINE | ID: mdl-33513803

Clinical use of 4-Allylpyrocatechol (APC), a potential antifungal agent from Piper betle, is limited because of its low water solubility. The current study explores the development of the self-nanoemulsifying drug delivery system (SNEDDS) containing APC (APC-SNEDDS) to enhance APC solubility. Results demonstrated that excipient type and concentration played an important role in the solubility of APC in the obtained SNEEDS. SNEDDS, comprising 20% Miglyol 812N, 30% Maisine 35-1, 40% Kolliphor RH40, and 10% absolute ethanol, provided the highest loading capacity and significantly increased water solubility of APC. Oil-in-water nanoemulsions (NE) with droplet sizes of less than 40 nm and a narrow size distribution were obtained after dispersing this APC-SNEDDS in water. The droplets had a negative zeta potential between -10 and -20 mV. The release kinetics of APC from APC-SNEDDS followed the Higuchi model. The NE containing 1.6 mg APC/mL had effective activity against Candida albicans with dose-dependent killing kinetics and was nontoxic to normal cells. The antifungal potential was similar to that of 1 mg nystatin/mL. These findings suggest that APC-SNEDDS are a useful system to enhance the apparent water solubility of APC and are a promising system for clinical treatment of oral infection caused by C. albicans.

11.
Pharmaceuticals (Basel) ; 13(11)2020 Nov 11.
Article En | MEDLINE | ID: mdl-33187352

Carbamide peroxide (CP) possesses a strong tooth bleaching activity, however, its clinical application is limited because of its instability in aqueous formulations. This study explores the improvement of CP stability and bleaching activity by loading CP in electrospun nanofibrous film (ENF). Polyvinylalcohol, polyvinylpyrrolidone, and silica were used as components for core-based nanofibers of ENF. Electrospinning feed aqueous solutions (EFASs) were developed for preparing CP loaded ENF (CP-ENF). Stability of CP in EFASs is significantly higher than in pure water. The highest stability of CP is found in PPS-CP3, composed of 0.5% CP, 5.5% polyvinylalcohol, 3% polyvinylpyrrolidone, and 1% silica. The results from X-ray diffraction indicate that CP is dispersed as a non-crystalline form in CP-ENFs. CP and the compositions of EFASs play a major role on characteristics and bleaching efficiency of CP-ENFs. Drug release of CP-ENFs is the first order kinetics. CP-ENF obtained from PPS-CP3 shows the highest drug entrapment efficiency, high adhesion, and suitable sustained release. Drug release mechanism is along with anomalous transport according to Korsmeyer-Peppas model. In an ex vivo study using human teeth, it shows the highest bleaching efficiency among the others. Therefore, CP-ENF obtained from PPS-CP3 is a promising ENF for clinical use.

12.
J Clin Med ; 8(5)2019 May 07.
Article En | MEDLINE | ID: mdl-31067835

Background: The purposes of this randomized clinical trial study was to compare the immediate loading of dental implants while employing digital workflow and conventional implants in terms of the success rate, marginal bone level, and patient satisfaction. Methods: Fifty patients who had edentulous area on the mandibular premolar or molar area were included in the study. Twenty-five patients were assigned to immediate loading implant treatment using the digital technique and 25 patients were assigned to conventional loading implant treatment. In the first group, the patients were received digital impression (Cerec Omnicam, Dentsply Sirona®, York, PA, USA), designed, producing zirconia crown, and inserted on the same surgery day. The second group, after a healing period of three months, was received analog impression following conventional impression for the zirconia crown. Clinical outcome and radiographic bone level were evaluated after three, six, and 12 months. Patient satisfaction was measured at 12 months after inserting the implant. Results: There was no implants and protheses failure in both groups. The mean resonance frequency analysis values at the day of surgery were 78.26 ± 4.09 in immediate loading using the digital group (ILD) and 73.74 ± 5.14 in the conventional loading group (CL), respectively. Insertion torque values at the day of surgery were 36.60 ± 12.64 in ILD and 38.8 ± 12.19 CL, respectively. The marginal bone level in CL at three, six, and 12 months were 0.14 ± 0.28 mm, 0.18 ± 0.30 mm, and 0.17 ± 0.29 mm, respectively, while in ILD at three, six, and 12 months were 0.18 ± 0.33 mm and 0.16 ± 0.27 mm and 0.15 ± 0.31, respectively. There was no statistically significant difference between the two groups. Only one question in patient satisfaction's questionnaire was "Now, can your dental implant and crown be used well?" had been significantly different in favor to the conventional group. Conclusion: Within the limitation of this study, it may be concluded that, after one-year follow up, there were no statistically significant differences between the immediate loading of dental implants employed from the digital workflow and conventional implant treatment technique in the success rate and marginal bone level. In patient satisfaction, there was only statistic significant difference in question related to implant prosthetic function in favor of the CL group, whereas the question concerning speaking, cleansing, price, and expectation displayed no difference.

13.
Int J Implant Dent ; 5(1): 1, 2019 Jan 14.
Article En | MEDLINE | ID: mdl-30637611

BACKGROUND: Despite the high survival rate of dental implants, screw loosening is frequently reported. Screw loosening can cause a misfit of the implant-abutment connection leading to peri-implantitis or abutment screw fracture. Therefore, studies about related factors and mechanism of screw loosening are needed. The aim of this study was to evaluate the decreasing pattern of removal torque values (RTVs) of a combined cone and octalobule index implant-abutment connection under different numbers of mechanical loading cycles. MATERIALS AND METHODS: The study was performed in accordance with ISO 14801:2007. Eighty-four implants with the combined cone and octalobule index implant-abutment connection (PW Plus dental implant system, PW Plus Company) were used. All abutment screws were tightened 30 N cm twice with a 10-min interval. The control group was without cyclic loading and the experimental groups underwent different numbers of loading cycles until 2,000,000 cycles. Then, the abutment screws of all samples were untightened to measure the RTVs. The data were analyzed using ANOVA and Tukey's HSD test. RESULTS: The RTVs of the control group decreased 7.78% compared to the insertion torque. All experimental groups from 50,000 to 2,000,000 cycles showed significant decreases in RTVs compared to the control group (P < 0.05). RTVs in the group of 50,000 cycles to 1,800,000 cycles did not change significantly, but there was a significant reduction of RTVs in the group of 2,000,000 cycles when compared to the group of 50,000 cycles (P < 0.05). CONCLUSIONS: According to the setting condition for the fatigue test complied to ISO 14801:2007, the RTVs of the combined cone and octalobule index implant-abutment connection reduced significantly after 50,000 cycles and did not change significantly until 2,000,000 cycles.

14.
Drug Discov Ther ; 12(5): 275-282, 2018.
Article En | MEDLINE | ID: mdl-30464158

In the present study, the modified white rice of Jasmine (JM) and Saohai (SH) were used to prepare the rice gels. Carbamide peroxide (CP) containing rice gels (CP rice gels) of JM (CP-JM) and SH (CP-SH) were prepared. The rice gels and CP rice gels show homogenous texture. Rice variety influences the characteristics and properties of the rice gels. Amylose content of JM was lower than SH. Rheological behavior of JM and CP-JM was pseudoplastic without thixotropy whereas that of SH and CP-SH was pseudoplastic with thixotropy. CP-SH showed higher adhesive property and viscosity than CP-JM whereas CP-JM showed faster in vitro drug release than CP-SH. For ex vivo efficacy evaluation, 55 normal human teeth were subjected to the CP rice gels. Samples were applied on tooth surface according to the dental bleaching techniques. For at-home bleaching technique, the CP rice gels with 10% and 20% CP were used with bleaching time of 8h and 4h, respectively. For in-office bleaching technique, the CP rice gels with 35% CP was used with bleaching time of 1 h. The developed CP rice gels showed significantly higher efficacy than the positive and negative controls. For at-home bleaching technique, CP-SH was the most effective gels whereas for in-office bleaching technique, CP-JM was the most effective gels.


Gels/administration & dosage , Gels/chemical synthesis , Oryza/chemistry , Tooth Bleaching Agents/chemistry , Carbamide Peroxide/chemistry , Gels/chemistry , Gels/pharmacology , Humans , Oryza/classification , Particle Size , Plant Extracts/chemistry , Random Allocation , Rheology , Tooth Bleaching/methods , Viscosity
15.
Drug Discov Ther ; 12(3): 126-132, 2018.
Article En | MEDLINE | ID: mdl-29998993

Carbamide peroxide (CP) is commonly used as a tooth whitening agent. However, efficacy of CP can be enhanced if it is in the suitable delivery system. In the present study, CP loaded in pigmented rice gels were developed and investigated for their physicochemical properties and tooth whitening efficacy. The modified pigmented rice of two varieties, Homnil (HN) and Doisket (DS) were prepared and used as a gelling agent. The outer appearance of the obtained rice gels containing 10% CP (CP-HN and CP-DS, respectively) were transparent and homogeneous texture. The pH of both rice gel bases was neutral but became slightly acidic after incorporating with CP. The adhesive property of HN gel was significantly higher than DS gels. In vitro drug release profile exhibited that the release of CP from CP-DS was significantly higher than CP-HN and the commercial gel (CP-CG), respectively. In vitro tooth whitening efficacy in 45 normal teeth revealed that the tooth whitening efficacy of the gels was time dependent. At the end of the treatment, CP-HN showed significantly higher tooth whitening efficacy than CP-DS and CP-CG, respectively. It is concluded that the physicochemical properties, particularly the adhesive and dissolution properties, play an important role in the tooth whitening efficacy of the CP gels.


Carbamide Peroxide/pharmacology , Gels , Oryza , Tooth Bleaching Agents/pharmacology , Tooth/drug effects , Carbamide Peroxide/administration & dosage , Chromatography, High Pressure Liquid , Drug Delivery Systems , Excipients , Humans , In Vitro Techniques , Tooth Bleaching Agents/administration & dosage
16.
Dent Mater J ; 37(3): 385-392, 2018 Jun 08.
Article En | MEDLINE | ID: mdl-29375092

This study evaluated the effects of surface pretreatment with different concentrations of sulfuric acid etching on surface properties and bonding between Polyetheretherketone (PEEK) and a resin composite. Six groups of surface pretreatment (no pretreatment, etched with 70, 80, 85, 90, and 98% sulfuric acid for 60 s) were treated on PEEK. Surface roughness, scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses were examined. Shear bond strength (SBS) and cross-sectional observations of the interfaces were performed. One-way ANOVA analysis revealed differences in surface roughness and SBS between groups. The 90 and 98% sulfuric acid etching significantly achieved the highest SBS (p<0.05). SEM and AFM demonstrated etched surfaces with wide and deep pores. The 90 and 98% sulfuric acid etching were suggested to be the optimal concentration to improve adhesion between PEEK and the resin composite.


Acid Etching, Dental/methods , Composite Resins/chemistry , Dental Bonding/methods , Ketones/chemistry , Polyethylene Glycols/chemistry , Sulfuric Acids/chemistry , Acrylates , Benzophenones , Materials Testing , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Polymers , Shear Strength , Surface Properties
17.
Dent Mater J ; 35(4): 668-74, 2016.
Article En | MEDLINE | ID: mdl-27477234

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.


Dental Bonding , Resin Cements , Acid Etching, Dental , Composite Resins , Materials Testing , Microscopy, Electron, Scanning , Shear Strength , Stress, Mechanical , Surface Properties
18.
Dent Mater J ; 31(4): 610-6, 2012.
Article En | MEDLINE | ID: mdl-22864214

The objective of this study was to clarify the effects of silane coupling agents and solutions of different polarity on polymethyl methacrylate (PMMA) bonding to alumina. Three silane coupling agents (3-methacryloxypropyltrimethoxysilane (MPS),3-aminopropyltriethoxysilane (APS) and N-2 (aminoethyl) 3-aminopropyltriethoxysilane) and 3 different polar solutions, 70% ethanol, isopropanol and toluene, were selected for silanization. Shear bond strengths were statistically compared with Tukey HSD(α=0.05). The alumina surfaces after silanization and shear bond test were examined with an energy dispersive spectrometer (EDS).The bond strengths of PMMA on the alumina with MPS (15.0 MPa), APS (13.8 MPa) in ethanol were greater than the others in nonthermocyclings. The bond strength decreased after thermocyclings. The ethanol groups were greater than the others. EDS revealed Si remaining on the alumina surface after the shear bond test. The results indicated that the silanization using MPS and APS with ethanol solution was effective.


Aluminum Oxide/chemistry , Dental Bonding , Polymethyl Methacrylate/chemistry , Silanes/chemistry , Solvents/chemistry , Analysis of Variance , Dental Stress Analysis , Electricity , Hot Temperature , Shear Strength , Solubility , Solutions , Spectrometry, X-Ray Emission , Surface Properties
19.
Dent Mater J ; 31(4): 623-8, 2012.
Article En | MEDLINE | ID: mdl-22864216

This study evaluated the different amounts of 3-methacryloxypropyltrimethoxysilane (MPS) coated alumina filler particles on flexural strength and wear resistance of alumina reinforced polymethyl methacrylate (PMMA) denture base. Ten mass% of alumina filler silanized with 0, 0.1, 0.2, or 0.4 mass% of MPS was blended with PMMA. PMMA without alumina particles served as control.Specimens were prepared for flexural strength and wear resistance tests (n=10). Flexural strength was determined using a 3-point bending test and volume loss was measured by in-vitro 2-body wear-testing. The results were analyzed by One-way ANOVA and Tamhane's test (α=0.05). Flexural strength ranged from 95.1-117.8 MPa, while volume loss ranged from 0.038-0.160 mm3. Statistical analysis indicated the 0.1 mass% MPS silanized group had significantly higher flexural strength and lower volume loss than the control group. Adding alumina filler silanized with 0.1 mass% MPS resulted in an improvement of the flexural strength and wear resistance of PMMA.


Dental Restoration Wear , Denture Bases , Methacrylates/chemistry , Polymethyl Methacrylate , Silanes/chemistry , Aluminum Oxide/chemistry , Pliability , Polymethyl Methacrylate/chemistry
20.
Dent Mater J ; 30(4): 461-8, 2011.
Article En | MEDLINE | ID: mdl-21778606

In this study, the wear resistance, hardness, elastic modulus, and the correlations between them of artificial denture teeth at the sub-enamel layer were examined. Four types of tested artificial denture teeth consisted of 3 conventional acrylic resin teeth (Cosmo HXL, Major Dent, and Yamahachi FX), 1 high cross-linked acrylic resin teeth (Trubyte Bioform IPN), 2 composite resin teeth (SR Orthosit PE, and Yamahachi PX), and 1 porcelain teeth (ACE Teeth). The two-body wear test was performed using a custom made pin on disc apparatus. Volume and weight loss were measured. Hardness and elastic modulus were also assessed by using a nanoindentation system. The results suggested wear resistance varied among the denture tooth materials. Wear resistance of high cross-linked acrylic resin teeth was the lowest. A definite relation between wear resistance and mechanical properties of materials could not be found in this study.


Dental Materials/chemistry , Dental Restoration Wear , Tooth, Artificial , Acrylic Resins/chemistry , Acrylic Resins/classification , Aluminum Oxide/chemistry , Carbon Compounds, Inorganic/chemistry , Composite Resins/chemistry , Dental Polishing/methods , Dental Porcelain/chemistry , Elastic Modulus , Hardness , Humans , Materials Testing , Methacrylates/chemistry , Microscopy, Electron, Scanning , Polymethyl Methacrylate/chemistry , Polyurethanes/chemistry , Silicon Compounds/chemistry , Surface Properties
...