{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T18:00:24Z","timestamp":1784743224351,"version":"3.55.0"},"reference-count":25,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2024,11,13]],"date-time":"2024-11-13T00:00:00Z","timestamp":1731456000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Thammasat University Research Fund","award":["TUFT 15\/2567"],"award-info":[{"award-number":["TUFT 15\/2567"]}]},{"name":"Rubber Technology Research Centre (RTEC), Mahidol University","award":["TUFT 15\/2567"],"award-info":[{"award-number":["TUFT 15\/2567"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dentistry Journal"],"abstract":"<jats:p>Background: Rubber dam clamps are used extensively in dentistry, especially during root canal treatment. However, existing rubber dam clamps have several drawbacks, including discomfort and potential damage to vital tissue in the oral cavity. To address these existing issues, a new rubber dam clamp should be developed. The aim of this study was to identify the optimum ratios of polypropylene and natural rubber (PP\/NR) for a customized rubber dam clamp in dentistry. This study was focused on the flexural strength of PP\/NR in various ratios. Moreover, the impact of autoclave sterilization was also considered. Methods: Six proportions of PP\/NR blends (100\/0, 90\/10, 80\/20, 70\/30, 60\/40 and 50\/50) were prepared and assessed for flexural strength using a three-point bending test. After this test, the PP\/NR blends with 100\/0, 90\/10 and 80\/20 ratios were selected and underwent autoclave sterilization for 1, 5 and 10 cycles. Eventually, the flexural strength testing was repeated and investigated. An analysis of variance and Tukey\u2019s test were used to evaluate the flexural strength of various PP\/NR blends before autoclave sterilization at p &lt; 0.05. An analysis of variance and Dunnett\u2019s T3 test were used to evaluate the flexural strength of selected PP\/NR blends before and after autoclave sterilization at p &lt; 0.05. Results: The results revealed that the flexural strength of PP\/NR blended materials showed a statistically significant difference in every group of this study. The autoclave sterilization test revealed that the flexural strength of the PP\/NR 90\/10 and 80\/20 ratios was significantly increased after sterilization for 1, 5 and 10 cycles. In addition, the PP\/NR 90\/10 ratio was also comparable to the 100\/0 ratio. The lower NR content in PP\/NR blends resulted in significantly higher flexural strength, and autoclave sterilization had an effect on this property. Conclusions: This study suggested that the PP\/NR blend with a 90\/10 ratio might be considered as an alternative material for developing rubber dam clamps.<\/jats:p>","DOI":"10.3390\/dj12110361","type":"journal-article","created":{"date-parts":[[2024,11,13]],"date-time":"2024-11-13T08:09:28Z","timestamp":1731485368000},"page":"361","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["The Flexural Strength and the Effect of the Autoclave Sterilization of Polypropylene\/Natural Rubber Blended Materials"],"prefix":"10.3390","volume":"12","author":[{"given":"Paphavarin","family":"Rangsantham","sequence":"first","affiliation":[{"name":"Division of Endodontics, Faculty of Dentistry, Thammasat University, Pathumthani 12121, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thitaporn","family":"Nonthiphalang","sequence":"additional","affiliation":[{"name":"Division of Restorative Dentistry, Faculty of Dentistry, Thammasat University, Pathumthani 12121, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panjaporn","family":"Wongwitthayakool","sequence":"additional","affiliation":[{"name":"Division of Oral Biology, Faculty of Dentistry, Thammasat University, Pathumthani 12121, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4019-9216","authenticated-orcid":false,"given":"Chakrit","family":"Sirisinha","sequence":"additional","affiliation":[{"name":"Rubber Technology Research Center (RTEC), Faculty of Science, Mahidol University, Nakhon Pathom 73170, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nantawan","family":"Krajangta","sequence":"additional","affiliation":[{"name":"Division of Restorative Dentistry, Faculty of Dentistry, Thammasat University, Pathumthani 12121, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panupat","family":"Phumpatrakom","sequence":"additional","affiliation":[{"name":"Division of Endodontics, Faculty of Dentistry, Thammasat University, Pathumthani 12121, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,13]]},"reference":[{"key":"ref_1","first-page":"e621","article-title":"Polyethylene terephthalate clamps: Optimization in endodontic and restorative practices","volume":"14","author":"Madalena","year":"2022","journal-title":"J. Clin. Exp. Dent."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1993","DOI":"10.1111\/iej.13605","article-title":"The impact of an enhanced infection control protocol on molar root canal treatment outcome-a randomized clinical trial","volume":"54","author":"Zahran","year":"2021","journal-title":"Int. Endod. J."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Stevenson, R.G. (2016). Best practices: Restorative complications. Avoiding and Treating Dental Complications: Best Practices in Dentistry, Wiley.","DOI":"10.1002\/9781118988053.ch1"},{"key":"ref_4","first-page":"3","article-title":"Effect of rubber dam clamps on demineralized cervical enamel of permanent teeth","volume":"85","author":"Mendes","year":"2018","journal-title":"J. Dent. Child."},{"key":"ref_5","first-page":"220","article-title":"Effect of Repeated Sterilization on the Tensile Strength of Rubber Dam Clamps","volume":"40","author":"Chhabra","year":"2018","journal-title":"Pediatr. Dent."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"548","DOI":"10.12968\/denu.2020.47.7.548","article-title":"Splendid isolation: A practical guide to the use of rubber dam Part 1","volume":"47","author":"Mackenzie","year":"2020","journal-title":"Dent. Update"},{"key":"ref_7","first-page":"1704","article-title":"Evaluation of the effect of different rubber dam clamps on the mandibular first molar with Finite element analysis","volume":"27","author":"Erdem","year":"2023","journal-title":"Comput. Methods Biomech. Biomed. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Luo, C., Liu, Y., Peng, B., Chen, M., Liu, Z., Li, Z., Kuang, H., Gong, B., Li, Z., and Sun, H. (2023). PEEK for oral applications: Recent advances in mechanical and adhesive properties. Polymers, 15.","DOI":"10.3390\/polym15020386"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1007\/s40090-018-0163-2","article-title":"Aging studies of a polypropylene and natural rubber blend","volume":"9","author":"Bendjaouahdou","year":"2018","journal-title":"Int. J. Ind. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/j.proeng.2013.12.204","article-title":"Mechanical and morphological properties of polypropylene\/epoxidized natural rubber blends at various mixing ratio","volume":"68","author":"Mohamad","year":"2013","journal-title":"Procedia Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"564","DOI":"10.4028\/www.scientific.net\/KEM.675-676.564","article-title":"Enhancing properties of deproteinized natural rubber with rice husk ash silica for use as a dental material","volume":"675\u2013676","author":"Saowapark","year":"2016","journal-title":"Key Eng. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Hashim, A.S., and Ong, S.K. (2017). Natural Rubber and Its Derivatives, IntechOpen.","DOI":"10.5772\/intechopen.69661"},{"key":"ref_13","first-page":"86","article-title":"Natural rubber-based mechanical modifiers for poly (lactic acid)","volume":"3","author":"Phinyocheep","year":"2020","journal-title":"Int. J. Sci. Innov. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Wissamitanan, T., Dechwayukul, C., Kalkornsurapranee, E., and Thongruang, W. (2020). Proper blends of biodegradable polycaprolactone and natural rubber for 3D printing. Polymers, 12.","DOI":"10.3390\/polym12102416"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1002\/pi.6133","article-title":"A novel preparation method of polypropylene\/natural rubber blends with improved toughness","volume":"70","author":"Lendvai","year":"2021","journal-title":"Polym. Int."},{"key":"ref_16","unstructured":"(2003). Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials (Standard No. ASTM D790)."},{"key":"ref_17","unstructured":"Sastri, V.R. (2021). Plastics in Medical Devices: Properties, Requirements, and Applications, William Andrew."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"175","DOI":"10.3758\/BF03193146","article-title":"G* Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences","volume":"39","author":"Faul","year":"2007","journal-title":"Behav. Res. Methods"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1038\/s41415-021-3016-x","article-title":"A simple guide to using dental dam","volume":"230","author":"Patel","year":"2021","journal-title":"Br. Dent. J."},{"key":"ref_20","unstructured":"Jacoby, S.R., Wehman, T.C., Lieberman, M., and Lieberman, F. (1988). Radiolucent Dental Dam Clamp. (4,787,849), U.S. Patent."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1081\/AMP-120005386","article-title":"Effect of dynamic crosslinking on crystallization and thermal degradation of polypropylene in polypropylene (PP)\/ethylene\u2013propylene DIENE (EPDM) rubber blends","volume":"17","author":"Jain","year":"2002","journal-title":"Mater. Manuf. Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"42773","DOI":"10.1002\/app.42773","article-title":"The effect of high temperature annealing process on crystallization process of polypropylene, mechanical properties, and surface quality of plastic parts","volume":"132","author":"Wang","year":"2015","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"111687","DOI":"10.1016\/j.matdes.2023.111687","article-title":"The effects of thermal annealing on the performance of material extrusion 3D printed polymer parts","volume":"226","author":"Yu","year":"2023","journal-title":"Mater. Des."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Sch\u00f6nhoff, L.M., Mayinger, F., Eichberger, M., Reznikova, E., and Stawarczyk, B. (2021). 3D printing of dental restorations: Mechanical properties of thermoplastic polymer materials. J. Mech. Behav. Biomed. Mater., 119.","DOI":"10.1016\/j.jmbbm.2021.104544"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1186\/s41205-021-00111-x","article-title":"Reusability of autoclaved 3D printed polypropylene compared to a glass filled polypropylene composite","volume":"7","author":"Fischer","year":"2021","journal-title":"3D Print. 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