Browsing by Subject "Calcium hydroxide"

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    Effect of different endodontic regeneration protocols on wettability, roughness and chemical composition of surface dentin
    (Elsevier, 2015-06) Yassen, Ghaeth H.; Sabrah, Alaa H. A.; Eckert, George J.; Platt, Jeffrey A.; Department of Restorative Dentistry, IU School of Dentistry
    Introduction We investigated the changes in physiochemical properties of dentin surfaces after performing different endodontic regeneration protocols. Methods Human dentin slices were randomized into 4 treatment groups and 1 untreated control group (n = 10). One treatment group was irrigated with sodium hypochlorite (NaOCl) for 5 minutes followed by EDTA for 10 minutes. The other 3 treatment groups were irrigated with NaOCl; treated for 4 weeks with triple antibiotic paste (TAP), diluted triple antibiotic paste (DTAP), or calcium hydroxide (Ca[OH]2); and then irrigated with EDTA. After treatment, contact angles between a blood analog and dentin surfaces were evaluated. Surface roughness and chemical composition were characterized using optical profilometry and energy-dispersive X-ray spectroscopy, respectively. One-way analysis of variance followed by Fisher least significant difference tests were used for statistical analyses. Results All treatment groups showed a significant reduction in wettability and a significant increase in surface roughness when compared with untreated dentin. Dentin treated with Ca(OH)2 had significantly lower wettability compared with all other groups. No significant difference in wettability was found between dentin treated with DTAP and TAP protocols. Dentin treated with TAP had significantly higher surface roughness compared with all other groups. Untreated dentin and NaOCl + EDTA–treated dentin had significantly higher calcium and phosphorus as well as significantly lower carbon compared with dentin treated with Ca(OH)2, DTAP, and TAP. Conclusions Endodontic regeneration protocols had a significant effect on wettability, surface roughness, and chemical composition of surface dentin. The Ca(OH)2 protocol caused a significant reduction in dentin wettability compared with TAP or DTAP protocols.
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    The effect of endodontic regeneration medicaments on mechanical properties of radicular dentin
    (2013) Yassen, Ghaeth H.; Platt, Jeffrey A., 1958-; Chu, Tien-Min Gabriel; Murray, Peter E.; Allen, Matthew R.; Vail, Mychel Macapagal, 1969-
    Endodontic regeneration treatment of necrotic immature teeth has gained popularity in recent years. The approach suggests a biological alternative to induce a continuous root development. In this project, three in vitro experiments were conducted to investigate the effect of three medicaments used in endodontic regeneration on mechanical properties and chemical structure of radicular dentin. In the first experiment, we investigated longitudinally the effect of medicaments on the indentation properties of the root canal surface of immature teeth using a novel BioDent reference point indenter. A significant difference in the majority of indentation parameters between all groups was found after one-week and one-month application of medicaments (p<0.0001): triple antibiotic paste (TAP) > double antibiotic paste (DAP) > control > calcium hydroxide [Ca(OH)2]. The four-week exposure of dentin to TAP and DAP caused 43% and 31% increase in total indentation distance outcome, respectively. In the second experiment, we investigated longitudinally the effect of medicaments on the chemical structure of immature radicular dentin by measuring the phosphate/amide I ratios of dentin using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy. Phosphate/amide I ratios were significantly different between the four groups after one week, two weeks and four week application of medicaments (p<0.0001): Ca(OH)2-treated dentin > untreated dentin > DAP-treated dentin > TAP-treated dentin. In the third experiment, we investigated longitudinally the effect of medicaments on root fracture resistance and microhardness of radicular dentin. For the microhardness, the two-way interaction between group and time was significant (p<0.001). TAP and DAP caused a significant and continuous decrease in dentin microhardness after one and three month application, respectively. The three-month intracanal application of Ca(OH)2 significantly increased the microhardness of root dentin. The time factor had a significant effect on fracture resistance (p<0.001). All medicaments caused significant decrease in fracture resistance ranging between 19%-30% after three month application compared to one week application. The three medicaments used in endodontic regeneration caused significant change in the chemical integrity of the superficial radicular dentin and significantly affected the indentation properties of the root canal surface. Furthermore, the three month intracanal application of medicaments significantly reduced the fracture resistance of roots.
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    Effect of intracanal medicaments used in endodontic regeneration procedures on microhardness and chemical structure of dentin
    (Synapse, 2015-05) Hamdon, Ghaeth Yassen; George, Joseph Eckert; Platt, Jeffrey Allen; Department of Restorative Dentistry, School of Dentistry
    OBJECTIVES: This study was performed to investigate the effects of different intracanal medicaments on chemical structure and microhardness of dentin. MATERIALS AND METHODS: Fifty human dentin discs were obtained from intact third molars and randomly assigned into two control groups and three treatment groups. The first control group received no treatment. The second control group (no medicament group) was irrigated with sodium hypochlorite (NaOCl), stored in humid environment for four weeks and then irrigated with ethylenediaminetetraacetic acid (EDTA). The three treatment groups were irrigated with NaOCl, treated for four weeks with either 1 g/mL triple antibiotic paste (TAP), 1 mg/mL methylcellulose-based triple antibiotic paste (DTAP), or calcium hydroxide [Ca(OH)2] and finally irrigated with EDTA. After treatment, one half of each dentin disc was subjected to Vickers microhardness (n = 10 per group) and the other half was used to evaluate the chemical structure (phosphate/amide I ratio) of treated dentin utilizing attenuated total reflection Fourier transform infrared spectroscopy (n = 5 per group). One-way ANOVA followed by Fisher's least significant difference were used for statistical analyses. RESULTS: Dentin discs treated with different intracanal medicaments and those treated with NaOCl + EDTA showed significant reduction in microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.05) compared to no treatment control dentin. Furthermore, dentin discs treated with TAP had significantly lower microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.0001) compared to all other groups. CONCLUSIONS: The use of DTAP or Ca(OH)2 medicaments during endodontic regeneration may cause significantly less microhardness reduction and superficial demineralization of dentin compared to the use of TAP.