• Journal of Mechanical Science and Technology
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• v.15 no.6
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• pp.727-734
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• 2001

The Tribological evaluation of commercial dental composite resins containing prepolymerized particle fillers was investigated. Composite resins such as Metafil, Silux Plus, Heliomolar, and Palfique Estelite were selected as specimens. In the wear tests, a ball-on-flat wear test method was used. The friction coefficient of Metafil was quite high. The wear resistance of Silux Plus and Palfique Estelite was better than that of Metafil and Heliomolar under the same experimental conditions. The main wear mechanism of the composite resins containing prepolymerized particle fillers was abrasive wear caused by the brittle fracture of the prepolymerized particles and the debonding of the filler and the matrix.

• Journal of Pharmaceutical Investigation
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• v.26 no.3
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• pp.221-232
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• 1996

An abrasive, calcium hydrogen phosphate dihydrate (DCPD), was synthesized in a Box-wilson experimental design by reactions between phosphoric acid and milk of lime, and calcium chloride and sodium phosphate solutions, and stabilized with TSPP and TMP. The optimum conditions for preparation of DCPD from phosphoric acid with milk of lime were such as; reaction temp.; $51.9^{\circ}C$, conc. of lime; 25.9%, conc. of phosphoric acd; 77.9%, drying temp.; $60.2^{\circ}C$ and final pH; 6.46. The physico-chemical and pharmaceutical properties of DCPD were showed as follows: glycerin absorption value(68 ml/100g), whiteness(99.5%), particle size(10.9 nm), pH(7.8), and set test(pass). XRD and SEM of DCPD indicated a monoclinic system crystallographically. $N_2$ adsorption isotherm curve by BET showed non porous type II form. The micromeritic parameters of DCPD showed that surface area was $3.27{\sim}4.6\;cm^{2}/g$ and pore volume, pore area and pore radius were negligible. The rheogram of the toothpaste containing DCPD showed pseudoplastic flow with yield value of 321, and thixotropic behavior forming hysteresis loop. These results meet the requirements as abrasive standard, and sythesized DCPD is expected as a good dental abrasive such as a high quality grade in practice.

• Restorative Dentistry and Endodontics
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• v.47 no.3
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• pp.29.1-29.10
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• 2022

Objectives: This study aimed to investigate the anti-erosive/abrasive effect of resin infiltration of previous deproteinized dentin. Materials and Methods: Dentin slabs were randomly assigned to 3 groups (n = 15): Control (no deproteinization; no resin infiltrant applied), RI (no deproteinization; resin infiltrant applied), and DRI (deproteinization; resin infiltrant applied). After undergoing the assigned treatment, all slabs were subjected to an in vitro cycling model for 5 days. The specimens were immersed in citric acid (0.05 M, pH = 3.75; 60 seconds; 3 times/day) and brushed (150 strokes). Between the challenges, the specimens were exposed to a remineralizing solution (60 minutes). The morphological alterations were analyzed by mechanical profilometry (㎛) and scanning electron microscopy (SEM). Data were submitted to one-way analysis of variance (ANOVA) and Tukey tests (p < 0.05). Results: Control and RI groups presented mineral wear and did not significantly differ from each other (p = 0.063). DRI maintained a protective layer preserving the dentin (p < 0.001). After erosive/abrasive cycles, it was observed that in group RI, only 25% of the slabs partially evidenced the presence of the infiltrating, while, in the DRI group, 80% of the slabs presented the treated surface entirely covered by a resin-component layer protecting the dentin surface as observed in SEM images. Conclusions: The removal of the organic content allows the resin infiltrant to efficiently protect the dentin surface against erosive/abrasive lesions.

• Restorative Dentistry and Endodontics
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• v.48 no.3
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• pp.26.1-26.12
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• 2023

Objective: This in vitro study aimed to evaluate the effects of different whitening toothpastes on a composite resin during at-home bleaching with 10% carbamide peroxide. Materials and Methods: Sixty samples (7 mm × 2 mm) were used for color and roughness analyses, while another 60 samples (3 mm × 2 mm) were utilized to assess microhardness. The factors analyzed included toothpaste, for which 5 options with varying active agents were tested (distilled water; conventional toothpaste; whitening toothpaste with abrasive agents; whitening toothpaste with abrasive and chemical agents; and whitening toothpaste with abrasive, chemical, and bleaching agents). Brushing and application of whitening gel were performed for 14 days. Surface microhardness (SMH), surface roughness (Ra), and color (ΔL^*, Δa^*, Δb, ΔE^*_ab, and ΔE₀₀) were analyzed. The Ra and SMH data were analyzed using mixed generalized linear models for repeated measures, while the color results were assessed using the Kruskal-Wallis and Dunn tests. Results: Between the initial and final time points, all groups demonstrated significant increases in Ra and reductions in SMH. No significant differences were found between groups for SMH at the final time point, at which all groups differed from the distilled water group. Conventional toothpaste exhibited the lowest Ra, while whitening toothpaste with abrasive agent had the highest value. No significant differences were observed in ΔL^*, Δa^*, and Δb. Conclusions: While toothpaste composition did not affect the color stability and microhardness of resin composite, combining toothbrushing with whitening toothpaste and at-home bleaching enhanced the change in Ra.

• Journal of Periodontal and Implant Science
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• v.51 no.5
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• pp.298-315
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• 2021

Purpose: Peri-implantitis therapy and implant maintenance are fundamental practices to enhance the longevity of zirconia implants. However, the use of physical decontamination methods, including hand instruments, polishing devices, ultrasonic scalers, and laser systems, might damage the implant surfaces. The aim of this systematic review was to evaluate the effects of physical decontamination methods on zirconia implant surfaces. Methods: A systematic search was conducted using 5 electronic databases: Ovid MEDLINE, PubMed, Scopus, Web of Science, and Cochrane. Hand searching of the OpenGrey database, reference lists, and 6 selected dental journals was also performed to identify relevant studies satisfying the eligibility criteria. Results: Overall, 1049 unique studies were identified, of which 11 studies were deemed suitable for final review. Air-abrasive devices with glycine powder, prophylaxis cups, and ultrasonic scalers with non-metal tips were found to cause minimal to no damage to implantgrade zirconia surfaces. However, hand instruments and ultrasonic scalers with metal tips have the potential to cause major damage to zirconia surfaces. In terms of laser systems, diode lasers appear to be the most promising, as no surface alterations were reported following their use. Conclusion: Air-abrasive devices and prophylaxis cups are safe for zirconia implant decontamination due to preservation of the implant surface integrity. In contrast, hand instruments and ultrasonic scalers with metal tips should be used with caution. Recommendations for the use of laser systems could not be fully established due to significant heterogeneity among included studies, but diode lasers may be the best-suited system. Further research-specifically, randomised controlled trials-would further confirm the effects of physical decontamination methods in a clinical setting.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.124-130
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• 1998

The wear characteristics and wear mechanisms of dental composite resins were investigated. Composite resins such as Metalii, Silux Plus, Heliomolar and Palfique Estelite were selected as specimens and contents of filler in specimens in order to analyze the effect of Prepolymerized Particle Fillers in friction and wear characteristics. Ball on flat wear tester was used for a wear test. Friction and wear tests are carried out at room temperature. The friction coefficient of Metafil was quite high relatively, and the wear resistance of Silux Plus and Palfique Estelite was better than that of Metafil and Hellomolar at the same experimental condition. The main wear mechanism is plastic flow and abrasive wear by crack propagation.

• Tribology and Lubricants
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• v.15 no.2
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• pp.212-217
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• 1999

The wear characteristics and wear mechanisms of dental composite resins were investigated. Composite resins such as Metafil, Silux Plus, Heliomolar and Palfique Estelite were selected as specimens and contents of filler in specimens in order to evaluate the effect of Prepolymerized Particle Fillers in friction and wear characteristics. Ball on flat wear tester was used for the wear test at room temperature. The friction coefficient of Metafil was quite high relatively, and the wear resistances of Silux Plus and Palfique Estelite were better than that of Metafil and Heliomolar at the same experimental condition. It was found that The main wear mechanism is plastic flow and abrasive wear by failure of filler's bond to the matrix.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.83-90
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• 2013

The aim of this study was to evaluate the abrasive effect and cleaning power of toothpaste containing tetrasodium pyrophosphate and cellulose. The relative dentin abrasivity, cleaning power by modified Stookey method, dentin abrasivity of brushing after Cola treatment and consumer survey were investigated with control toothpaste containing dental type silica as an abrasive. The results obtained were as follows: 1. Experimental toothpaste hardly influenced dentin abrasivity, but control toothpaste had an effect on dentin abrasivity significantly (p<0.05). 2. There was no significant difference in cleaning power between experimental and control toothpaste (p>0.05). 3. Experimental toothpaste hardly influenced dentin abrasivity, despite 100 or 1,000 times of brushing after Cola treatment, but control toothpaste showed a big increase in dentin abrasivity as the number of brushing has been increased (p<0.05). 4. According to the consumer survey results, there was no difference between control and experimental toothpaste in the satisfaction rate of refreshing sensation, the satisfaction rate of the lasting effect of refreshing sensation and the overall satisfaction rate of the toothpaste (p>0.05). These results showed a possibility to make abrasive free toothpaste having cleaning power without dentin abrasivity.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.615-630
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• 2002

Various long-term studies have shown that titanium implants as abutments for different types of prostheses have become a predictable adjunct in the treatment of partially or fully edentulous patients. The continuous exposure of dental implants to the oral cavity with all its possible contaminants creates a problem. A lack of attachment, together with or caused by bacterial insult, may lead to peri-implantitis and eventual implant failure. Removal of plaque and calculus deposits from dental titanium implants with procedures and instruments originally made for cleaning natural teeth or roots may cause major alterations of the delicate titanium oxide layer. Therefore, the ultimate goal of a cleaning procedure should be to remove the contaminants and restore the elemental composition of the surface oxide without changing the surface topography and harming the surrounding tissues. Among many chemical and mechanical procedure, air-powder abrasive have been known to be most effective for cleaning and detoxification of implant surface. Most of published studies show that the dental laser may be useful in the treatment of pen-implantitis. $CO_2$ laser and Soft Diode laser were reported to kill bacteria of implant surface. The purpose of this study was to obtain clinical guide by application these laser to implant surface by means of Non-contact Surface profilometer and X-ray photoelectron spectroscopy(XPS) with respect to surface roughness and atomic composition. Experimental rough pure titanium cylinder models were fabricated. All of them was air-powder abraded for 1 minute and they were named control group. And then, the $CO_2$ laser treatment under dry, hydrogen peroxide and wet condition or the Soft Diode laser treatment under Toluidine blue O solution condition was performed on the each of the control models. The results were as follows: 1. Mean Surface roughness(Ra) of all experimental group was decreased than that of control group. But it wasn't statistically significant. 2. XPS analysis showed that in the all experimental group, titanium level were decreased, when compared with control group. 3. XPS analysis showed that the level of oxygen in the experimental group 1, 3($CO_2$ laser treatment under dry and wet condition) and 4(Soft Diode laser was used under toluidine blue O solution) were decreased, when compared with control group. 4. XPS analysis showed that the atomic composition of experimental group 2($CO_2$ laser treatment under hydrogen peroxide) was to be closest to that of control group than the other experimental group. From the result of this study, this may be concluded. Following air-powder abrasive treatment, the $CO_2$ laser in safe d-pulse mode and the Soft Diode laser used with photosensitizer would not change rough titanium surface roughness. Especially, $CO_2$ laser treatment under hydrogen peroxide gave the best results from elemental points of view, and can be used safely to treat peri-implantitis.

• Restorative Dentistry and Endodontics
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• v.2 no.1
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• pp.15-19
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• 1976

The author studied on the transfer of radioactive fluorine ($^{18}F$) to dental hard tissue through animal experiments which was divided into two groups. First group of rats were sacrified 1, 2, 5, 10 and 20 minutes after intraperitoneal injection. Second group were sacrified 1 and 3 minutes after topical application on anterior teeth. The teeth were removed and sectioned by means of abrasive wheel and polished on india stone as thick as about 50 microns. Autoradiograph picture was made by close contact of high-speed dental X-ray film on prepared specimen for 2 hours. The results of this study were as follows; 1) There was no evidence of transfer of $^{18}F$ on dental hard tissue on the cases of 1, 2 and 5 minutes survival after intraperitoneal injection. 2) Radioactive sodium fluorine incorporated to dental hard tissue was slight and diffuse at 10 minutes cases and significant incorporated picture was noticed at 20 minutes cases in intraperitoneal injection. 3) On topical application groups incorporated $^{18}F$ to enamel was traced clearly only on enamel surface at 1 minute cases and significant transfer into whole enamel was found at 3 minutes cases.