• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.278-287
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• 2015

PURPOSE. The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. MATERIALS AND METHODS. Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study. One hundred five specimens were fabricated. For the color stability test, specimens were immersed in the coffee and green tee for 1 and 8 weeks. Color change was measured by spectrometer. Water sorption was tested after 1 and 8 weeks immersion in the water. For the test of cytotoxicity, cell viability assay was measured and cell attachment was analyzed by FE-SEM. RESULTS. All types of denture base resin showed color changes after 1 and 8 weeks immersion. However, there was no significant difference between denture base resins. All specimens showed significant color changes in the coffee than green tee. In water sorption test, thermoplastic acrylic resin showed lower values than conventional heat-polymerized acrylic resin and thermoplastic polyamide resin. Three types of denture base showed low cytotoxicity in cell viability assay. Thermoplastic acrylic resin showed the similar cell attachment but more stable attachment than conventional heat-polymerized acrylic resin. CONCLUSION. Thermoplastic acrylic resin for the non-metal clasp denture showed acceptable color stability, water sorption and cytotoxicity. To verify the long stability in the mouth, additional in vitro studies are needed.

• 대한치과보철학회지
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• 제40권4호
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• pp.309-322
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• 2002

The purpose of this study was to investigate the cytotoxicity and mutagenicity of denture base resins. According to manufacturer's instructions, resin specimens were made. Group 1 : heat-polymerizing acrylic resin (Luciton $199^{(R)}$) Group 2 : heat-polymerizing acrylic resin containing polyhedraloligosilsesquioxane(POSS resin) Group 3 : auto-polymerizing acrylic resin (Repair $Acrylic^{(R)}$) Group 4 : direct relining auto-polymerizing acrylic resin (Tokuso $Rebase^{(R)}$). Fresh specimens 24 hrs. and 72 hrs. soaked specimens in distil)ed water were made. Responses with metabolic assay and mutagenesis assay to eluates from resin specimens were measured. Cultures with medium alone provided controls. Cytotoxicity was assessed with agar overlay test. The results were as follows; 1. Group 4 showed higher cytotoxicity than Group 1, Group 2 and Group 3 in fresh, 24-an4 72-hour immersion caries (p<.05). Group 3 showed higher cytotoxicity than Group 2 in fresh cases and showed higher cytotoxicity than Group 1 and Group 2 in 24-and 72-hour immersion cases (p<.05) . Group 1 and Group 2 showed no significant difference. 2. All acrylic denture base resins skewed significant increase of cell activity as immersion time increased (p<.05). 3. Auto-polymerizing acrylic denture base resins skewed higher cytotoxicity than heat-polymerizing acrylic denture base resins (p<.05). 4. All acrylic denture base resins showed lower mutagenicity than controls (p<.05).

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.453-462
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• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

• 한국재료학회지
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• 제33권2호
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• pp.47-53
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• 2023

When exposed to different types of bacteria in the oral cavity, denture based resins are prone to bacteria attachment. The purpose of this study was to investigate the physical, biological, and antimicrobial properties of denture base resins coated with Peony extract (200, 400, and 600 ㎍/mL). Specifically, the surface properties (microhardness, contact angle, and color change of the coated specimens), cell cytotoxicity (measured using MTT assay), and antimicrobial activity (against S. mutans (Streptococcus mutans) and C. albicans (Candida albicans) using a growth inhibition assay) were evaluated. The polyphenol content was measured using ultraviolet-visible (UV-vis) spectrometry. The experimental groups (specimens coated with Peony extract) and a control group (specimens coated without Peony extract) were statistically compared using a one-way analysis of variance and Tukey's post-hoc tests. No statistically significant differences in surface properties or cell cytotoxicity were observed, which demonstrated their biocompatibility. Conversely, a statistically significant difference in antimicrobial activity was observed between the experimental and control groups after 48 h. This confirms the antimicrobial activity of the denture base resin coated with Peony extract and demonstrates that it is a promising dental material for preventing stomatitis.

• 대한치과보철학회지
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• 제30권2호
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• pp.247-257
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• 1992

The present study quantitates the in vitro cytotoxicity of a variety of denture base acrylic resins using cell culture techniques combined with image analysis to measure nuclear area and DNA contents. In this study, a comparison was made among direct curing, heat curing and microwave curing resins. The results obtained from this study were as follows : 1. Morphologically, cell process and nucleus became prominent but macroscopic difference according to the resins were nit observed. In addition, increased cellular density around the specimen were observed. 2. In DNA contents measurements, $S-G_2M$ phase cell was 15.47%, 14.58% in control and heat curing resin on 1st day and the others group $21.39\sim33.36%$ were measured. 3. Nuclear area and DNA contents were increased on 3rd day except DNA content of the microwave curing resin group. These results suggest that denture base acrylic resins stimulate gingival fibroblasts in vitro, especially stimulation of direct curing resin is larger and longer than the others.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.98-107
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• 2015

PURPOSE. The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS. 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS. Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION. Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.