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Molaei M, Mohammadzadeh A, Ghasemi A, Badiee M. Effect of dry and wet finishing and polishing on color change and opacity of nanofill and nanohybrid composites. BMC Oral Health 2024; 24:287. [PMID: 38419033 PMCID: PMC10903010 DOI: 10.1186/s12903-024-03944-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 01/26/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND As superior esthetic is one of the main reasons for using composite resins, it is very important to be familiar with factors and techniques affecting their optical properties and appearance. AIM The aim of this study was comparing the effect of finishing and polishing with and without water coolant, on the color change and opacity of composite resin materials. METHODS Composites used for preparing samples were Z250 (microhybrid), Z350XT (nanofilled), and Z550 (nanohybrid). Then divided into 4 groups of 5 depending on finishing and polishing technique (dry or wet) and time (immediate and after twenty-four hours). After polishing, samples were assessed using a spectrophotometer. Color change and opacity were determined. Data was analyzed using Kolmogorov-Smirnov, ANOVA and Tukey HSD tests. RESULTS Type of material at both time had a significant effect on ΔE and opacity. Our results in dry and wet technique immediately(T0) showed that the highest and lowest ΔE and opacity belong to Z350XT (p < 0.001). After Twenty-four hours (T24), opacity of Z250 in wet condition was higher than dry condition (p < 0.001). CONCLUSIONS Wet or dry technique was only effective on color in immediate polishing. Regarding opacity, technique was only effective in case of delayed polishing.
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Affiliation(s)
- Mehdi Molaei
- School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Anoosh Mohammadzadeh
- School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amir Ghasemi
- Dental Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Badiee
- School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.
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Çınar B, Eren D, Akın Ş. Effect of Low pH Dietary Supplements on Discoloration of Resin Composites. Niger J Clin Pract 2023; 26:1784-1791. [PMID: 38158343 DOI: 10.4103/njcp.njcp_345_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 11/13/2023] [Indexed: 01/03/2024]
Abstract
AIM This study aimed to evaluate the impact of the consumption of low pH dietary supplements on the color stability of different resin composites. MATERIALS AND METHODS Three different restorative materials were used for this in vitro study: Filtek One Bulk-Fill (FOB), Filtek Z550 (Z550), and Fill-Up (FUP). Samples fabricated from each composite group were divided into four subgroups, and color measurements were performed at baseline. The control subgroup was stored in distilled water, and the other three subgroups were immersed in acidic dietary supplement solutions (Redoxon, Supradyn, and Voonka Collagen Shake) for 2 minutes daily for 28 days. Color measurements were obtained using a digital spectrophotometer. Color change values (ΔE1) were calculated after each color measurement. Next, all samples were immersed in a coffee solution for 7 days and repeat color measurements were taken to determine ΔE2 values. The study groups were compared using the Kruskal-Wallis test (α =0.05). RESULTS ΔE1 values were significantly different among the groups (P < 0.05). While Voonka Collagen Shake produced the greatest discoloration in FOB (1.67 ± 1.08) and Filtek Z550 (3.59 ± 1.90) materials, Fill-Up showed the highest discoloration (3.14 ± 0.37) with Supradyn. Analysis of ΔE2 values demonstrated a significant difference only for the Filtek Z550-Redoxon group versus the control group (P < 0.05). CONCLUSION Acidic dietary supplements not only produce color alterations in resin composites but also reduce the staining resistance of the composite further, depending on the type of composite and dietary supplement. Consumption of staining food after taking Redoxon effervescent tablets produces greater discoloration in Filtek Z550 restorations compared with other restorative materials.
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Affiliation(s)
- B Çınar
- Department of Restorative Dentistry, Sivas Cumhuriyet University Faculty of Dentistry, Sivas, Turkey
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Cubukcu I, Gundogdu I, Gul P. Color match analysis of single-shade and multi-shade composite resins using spectrophotometric and visual methods after bleaching. Dent Mater J 2023; 42:826-834. [PMID: 37821366 DOI: 10.4012/dmj.2023-115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
The aim of this study is to evaluate the color match of the materials after the staining and bleaching procedures applied to the teeth restored with single-shade and multi-shade composite resins. Cavities prepared on the facial surface of human incisors were restored with two different composite resins. After 24 h, the color matching parameters between the initial filling-tooth of the samples were recorded. Then, the color measurements of the samples subjected to the coloring process were repeated. Each composite resin group was randomly divided into 2 subgroups and home and office bleaching methods were applied to the samples. After bleaching, color measurements were repeated. In terms of periods, a statistically significant difference was found in ΔE values 1 day and 28 days after bleaching (p<0.05). In addition, it was found that the color match between filling-tooth was generally weaker in Omnichroma material and after home bleaching.
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Affiliation(s)
- Ipek Cubukcu
- Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University
| | - Iklima Gundogdu
- Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University
| | - Pinar Gul
- Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University
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Checchi V, Forabosco E, Dall'Olio F, Kaleci S, Giannetti L, Generali L. Assessment of colour modifications in two different composite resins induced by the influence of chlorhexidine mouthwashes and gels, with and without anti-staining properties: An in vitro study. Int J Dent Hyg 2023. [PMID: 37691471 DOI: 10.1111/idh.12747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/12/2023] [Accepted: 08/28/2023] [Indexed: 09/12/2023]
Abstract
OBJECTIVES Chlorhexidine (CHX)-based products are the most effective chemical agents used in plaque control and oral disinfection. One of their side effects is tooth and restoration staining. For this reason, CHX products with anti-discolouration systems (ADS) have been developed. The aim of this in vitro study was to compare different CHX-based products (gel and mouthwash) with or without ADS in composite colour modification. METHODS Two hundred specimens were created, 100 of which were made of packable composite and 100 of flowable composite. After 24 h, colour coordinates (L*, a*, b*, C*, h°) were recorded using a spectrophotometer (T0). Then, all samples were subjected to a CHX/tea staining model and immersed in human saliva for 2 min. Composite specimens were divided in 10 groups (N = 20). Control groups (PC, FC) were soaked in distilled water and test groups (PG, PGads, FG, FGads, PM, PMads, FM and FMads) were immersed in CHX-based solutions or brushed with CHX gel. Then the cycle was repeated 6 times, and colour differences (ΔEab and ΔE00 ) were finally calculated. RESULTS Through flowable composites, FC and FG showed the highest colour differences, respectively ΔEab = 3.48 ± 1.0, ΔE00 = 2.24 ± 0.6 and ΔEab = 2.95 ± 1.3, ΔE00 = 1.53 ± 0.6. In the composite groups instead, PM and PMads showed the highest colour differences, respectively ΔEab = 2.78 ± 1.3, ΔE00 = 1.94 ± 0.8 and ΔEab = 2.71 ± 1.4, ΔE00 = 1.84 ± 0.9. CONCLUSIONS CHX-containing products are able to cause stains on restorative composite materials. Discolouration is more likely to occur in flowable composites than packable composites, and ADS-containing products cause fewer pigmentations than CHX products without ADS. Packable composites showed more staining after mouthwash treatment, whereas flowable composites underwent higher discolouration after treatment with gels.
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Affiliation(s)
- V Checchi
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
| | - E Forabosco
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, Modena, Italy
| | - F Dall'Olio
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
| | - S Kaleci
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
| | - L Giannetti
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
| | - L Generali
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance, University of Modena and Reggio Emilia, Modena, Italy
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Farahani S, Faghihi T, Ranjbar Omrani L, Chiniforush N, Ahmadi E, Karimi M, Abbasi M. Effect of Laser and Conventional Office Bleaching and Polishing on the Color Change of Stained Nanohybrid and Microhybrid Composite Resin. Int J Dent 2023; 2023:9912560. [PMID: 37547816 PMCID: PMC10403332 DOI: 10.1155/2023/9912560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/28/2023] [Accepted: 07/10/2023] [Indexed: 08/08/2023] Open
Abstract
Aim The present study investigated the effects of laser and conventional in-office bleaching, and polishing on the color of stained composite resin. Materials and Methods A microhybrid composite (Clearfil AP-X) and a nanohybrid composite (Grandio) were selected. Twenty-four discs (2 × 10 mm) for each composite were prepared. The samples were immersed in coffee solution (25 g of coffee in 250 mL water) for seven days. Then the samples were divided into three groups (n = 8) and the stains were removed using bleaching (with Opalescence Xtra Boost), diode laser irradiation with Heydent material and a Sof-Lex polishing kit. The L ∗a ∗b ∗ color parameters were determined using a spectrophotometer before and after immersion and after stain removal procedures, and the overall color changes (ΔE) were calculated. The data were analyzed with two-way analysis of variance. Results In the Clearfil composite resin group, the mean ΔE compared to the baseline using in-office bleaching, laser irradiation, and Sof-Lex polishing kit were 3.31, 3.35, and 4.93, respectively. These values with the Grandio composite resin were 3.31, 6.35, and 4.57, respectively. The highest capacity to remove stains was related to the conventional in-office bleaching method. Grandio composite resin underwent more color changes than Clearfil composite resin significantly (P-value < 0.05). Conclusion Both composite resins exhibited color changes after immersion in the discoloring solution. However, after staining-removing procedures, the ΔE values decreased. Decreases in the ΔE values were not sufficient to restore the color to that before immersion in the discoloring solution with any stain-removing methods.
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Affiliation(s)
- Shakiba Farahani
- Department of Restorative Dentistry, Dental School, Tehran University of Medical Sciences, Tehran, Iran
| | - Taraneh Faghihi
- Department of Pediatric Dentistry, Faculty of Dentistry, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Ladan Ranjbar Omrani
- Department of Restorative Dentistry, Dental School, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasim Chiniforush
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
| | - Elham Ahmadi
- Department of Restorative Dentistry, Dental School, Tehran University of Medical Sciences, Tehran, Iran
| | - Mandana Karimi
- Department of Restorative Dentistry, Dental School, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdi Abbasi
- Department of Restorative Dentistry, Dental School, Tehran University of Medical Sciences, Tehran, Iran
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Althaqafi KA, Alshabib A. Effect of Bleaching Agents on Discoloured Resin-Based Composites for Direct Restorations: A Systematic Review. JOURNAL OF PHARMACY AND BIOALLIED SCIENCES 2023; 15:S1-S10. [PMID: 37654353 PMCID: PMC10466665 DOI: 10.4103/jpbs.jpbs_528_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/14/2022] [Accepted: 12/18/2022] [Indexed: 09/02/2023] Open
Abstract
The purpose of the review was to assess the influence of office and home bleaching on the color durability after staining of resin-based composites (RCs) for direct restorations. A web-based search for possibly relevant scientific papers in the English language between January 2013 and August 2022 was conducted in the databases such as PubMed, Scopus, Cochrane Library, and EMBASE. In-vitro studies that explored the influence of in-office and other bleaching treatments on the discolored RC for direct restorations in extracted human teeth were included. Case studies, case series, animal studies, systematic reviews, and letters to the editor were not considered. A total of 212 articles from a web-based search and 32 studies from a manual search were retrieved. After removal of duplicate records, 181 titles and abstracts were reviewed for eligibility; 92 were chosen for full-text analysis, and nine in-vitro studies matched the inclusion criteria. The two examiners examined the methodological quality of the selected studies independently based on the study design, methodological soundness, and data analysis. Distinct values were assigned to studies evaluating color variations of stained RC subjected to bleaching agents. The methodological quality scores were expressed as a percentage of the highest possible score based on the established scoring system and categorized as indicating a low, moderate, and high level of evidence. The reversal of color alterations following home and office bleaching was found to be dependent on the RC used. Within the limitations of the in-vitro investigations, it was deduced that the bleaching agents were successful in eliminating stains and improving the durability of the color to near baseline values.
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Affiliation(s)
- Khaled Abid Althaqafi
- Department of Restorative Dentistry, Faculty of Dentistry, College of Dental Medicine, University of Umm Al Qura, Makkah, Saudi Arabia
| | - Abdulrahman Alshabib
- Department of Restorative Dentistry, Faculty of Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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Hashemikamangar SS, Farahani S, Khoshgoo S, Doroudgar P. Comparative Efficacy of Four Stain Removal Methods for Bleach-Shade Composite Resins after Immersion in Staining Solutions: An In Vitro Study. Int J Dent 2023; 2023:8909288. [PMID: 37342250 PMCID: PMC10277192 DOI: 10.1155/2023/8909288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/18/2023] [Accepted: 05/02/2023] [Indexed: 06/22/2023] Open
Abstract
Introduction Bleach-shade composite resins were recently introduced to the market due to the high demand of patients for whiter teeth. This study sought to compare four stain removal methods for bleach-shade composite resins. Materials and Methods Seventy-two discs were fabricated from each of the Filtek Z350 XT and Gradia XBW composite resins and immersed in coffee or sour cherry juice staining solutions. Each group was then divided into four subgroups to assess the efficacy of four stain removal methods (finishing with soft-lex disk "brush with pumice" bleaching with carbamide peroxide 16%, bleaching with hydrogen peroxide 40%). The color of each specimen was measured by Easyshade spectrophotometer, and data were analyzed using SPSS 25 statistical package for social sciences. Results The home-bleaching technique was more effective than the office-bleaching and pumice for the removal of sour cherry juice stain (ΔE = 1.93) and coffee stain (ΔE = 3.32) from Gradia composite discs, almost returning the baseline original color. The Sof-Lex discs were more effective than the pumice for the removal of sour cherry juice stain (ΔE = 4.11) and coffee stain (ΔE = 4.93) from Z350 composite discs but not return the baseline original color. Conclusions Filtek Z350 had more discoloration than Gradia Direct. The different materials and solutions reacted differently to the four stain removal methods. In GCJ group after all stain removal methods, ΔE reduced to a clinically acceptable level.
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Affiliation(s)
| | - Shakiba Farahani
- Restorative Departments, Dental School, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Parisa Doroudgar
- Dental School, Tehran University of Medical Sciences, Tehran, Iran
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Allccahuaman-Avalos R, Medina-Sánchez R, Castro-Ramirez L, Ladera-Castañeda M, Cervantes-Ganoza L, Martínez-Campos R, Solís-Dante F, Aliaga-Mariñas A, Verástegui-Sandoval A, Cayo-Rojas C. In Vitro Color Stability Evaluation of Three Polished and Unpolished Nanohybrid Resin Composites Immersed in a 0.12% Chlorhexidine-Based Mouthwash at Different Times. Polymers (Basel) 2023; 15:polym15061339. [PMID: 36987120 PMCID: PMC10055837 DOI: 10.3390/polym15061339] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/26/2023] [Accepted: 03/02/2023] [Indexed: 03/12/2023] Open
Abstract
The use of chlorhexidine-based mouthwashes on resin composites with rough surfaces can cause discoloration which compromises the esthetic of patients. The present study aimed to evaluate the in vitro color stability of Forma (Ultradent Products, Inc., South Jordan), Tetric N-Ceram (Ivoclar Vivadent, Schaan, Liechtenstein) and Filtek Z350XT (3M, ESPE, St. Paul, MN, USA) resin composites, with and without polishing, after being immersed in a 0.12% chlorhexidine (CHX)-based mouthwash at different times. The present in vitro experimental and longitudinal study used 96 nanohybrid resin composite blocks (Forma, Tetric N-Ceram and Filtek Z350XT) 8 mm in diameter and 2 mm thick, evenly distributed. Each resin composite group was divided into two subgroups (n = 16) with and without polishing and then immersed in a 0.12% CHX-based mouthwash for 7, 14, 21 and 28 days. Color measurements were performed with a calibrated digital spectrophotometer. Nonparametric tests were used to compare independent (Mann–Whitney U and Kruskal–Wallis) and related (Friedman) measures. In addition, the Bonferroni post hoc correction was used considering a significance level of p < 0.05. All polished and unpolished resin composites presented color variation < 3.3 when immersed for up to 14 days in 0.12% CHX-based mouthwash. The polished resin composite with the lowest color variation (ΔE) values over time was Forma, and the one with the highest values was Tetric N-Ceram. When comparing the color variation (ΔE) over time, it was observed that the three resin composites, with and without polishing, presented a significant change (p < 0.001), although these changes in color variation (ΔE) were evident from 14 days between each color acquisition (p < 0.05). The unpolished Forma and Filtek Z350XT resin composites showed significantly more color variation than the same polished ones at all times when immersed in a 0.12% CHX-based mouthwash for 30 s daily. In addition, every 14 days, all three resin composites with and without polishing showed a significant color change, while, every 7 days, color stability was maintained. All the resin composites showed clinically acceptable color stability when exposed for up to 14 days to the above-mentioned mouthwash.
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Affiliation(s)
| | | | | | - Marysela Ladera-Castañeda
- Research Team “Salud Pública—Salud Integral”, Faculty of Dentistry, Postgraduate School, Universidad Nacional Federico Villarreal, Lima 15001, Peru
| | | | - Reynaldo Martínez-Campos
- Oral Rehabilitation Department, School of Stomatology, Universidad Científica del Sur, Lima 15067, Peru
| | | | - Ana Aliaga-Mariñas
- Research Team “Salud Pública—Salud Integral”, Faculty of Dentistry, Postgraduate School, Universidad Nacional Federico Villarreal, Lima 15001, Peru
| | - Arturo Verástegui-Sandoval
- Faculty of Health Sciences, Professional Academic School of Dentistry, Universidad Privada Norbert Wiener, Lima 15046, Peru
| | - César Cayo-Rojas
- School of Stomatology, Universidad Privada San Juan Bautista, Lima 15067, Peru
- Correspondence:
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AKLEYİN E, BAKIR EP, ÜNAL S, POLAT G, YENİÇERİ ÖZATA M. Effect of single serve sachet powder drinks on color stability of a nano hybrid composite resin. JOURNAL OF HEALTH SCIENCES AND MEDICINE 2023. [DOI: 10.32322/jhsm.1180255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Aim: Nano-filled composite resin materials used for aesthetic purposes have better mechanical, polish ability, and color stability properties compared to other composite resin types. The aim of this in vitro study was to evaluate the effect of 5 different single serve sachet powder drinks popular among adolescents in recent years on the color change of Nano hybrid composite resin material.
Material and Method: In this study, Nano hybrid composite resin (Filtek Z550) and five different types of sachet drinks (cherry flavored powdered drink, instant sachet Turkish coffee, instant sachet filter coffee, instant tea, 3-in-1 granulated coffee) were used. A total of 42 2×10 mm disc-shaped samples were prepared. The prepared samples were kept in distilled water in an oven at 37 ˚C for 24 hours and the initial color measurements were made with a spectrophotometer (Vita Easy Shade Advance 4.0., Germany). The samples were divided into 6 groups (n=7) to be kept in 5 colorant solutions and distilled water (control group). Composite samples were kept in an oven at 37°C and the solutions were changed once a week. Color change was measured before and after 1, 7, and 28 days of immersion. Shapiro Wilk test was used to check whether the data conformed to normal distribution. The variables were analyzed with one-way analysis of variance ANOVA and post-hoc Tukey test (p
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Klarić Sever E, Tarle A, Soče M, Grego T. Direct Radiotherapy-Induced Effects on Dental Hard Tissue in Combination With Bleaching Procedure. FRONTIERS IN DENTAL MEDICINE 2021. [DOI: 10.3389/fdmed.2021.714400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
Introduction: The aim of this study was to evaluate the effects of radiation and tooth bleaching on the physical and morphological properties of enamel and dentin on permanent teeth.Materials and Methods: Eighty fresh, non-carious third molars were used in this study. Before cutting the crown in half, the teeth samples were randomly allocated to treatment and control groups by using a lottery method. The first group (n = 20) underwent standard radiation protocol (2 Gy/fraction/day, 5 days/week) with bleaching treatment afterward using 16% carbamide peroxide gel, the second group (n = 20) underwent standard radiation protocol with afterward bleaching treatment using 38% hydrogen peroxide, the third group (n = 20) underwent a short, one strong, experimental dose of 70 Gy with afterward bleaching treatment using 16% carbamide peroxide gel, and the fourth group (n = 20) underwent one strong, experimental dose of 70 Gy with afterward bleaching treatment using 38% hydrogen peroxide gel. Groups 5–8 (n = 20) served as control as they underwent only bleaching treatment. Vickers microhardness and surface roughness were performed before (initial) and after irradiation and before bleaching or after only bleaching. The effects of irradiation and bleaching on microhardness (or roughness) of enamel and dentin were analyzed in the repeated-measures ANOVA model.Results: Enamel microhardness after experimental single 70-Gy irradiation or after standard radiation protocol and bleaching with 16 or 38% gel was not statistically significant from microhardness in the control group (p > 0.05). There was a statistically significantly greater reduction in the average microhardness of enamel and dentin during bleaching with 38% gel compared to 16% for both radiation protocols (p < 0.001). After experimental 70-Gy irradiation and bleaching, a 16% statistically significant increase in surface roughness was found for enamel (p = 0.006) and dentin (p = 0.018), while this was not recorded for 38% gel. There was a statistically significantly greater increase in the average roughness of enamel and dentin during bleaching with 38% gel compared to 16% (p < 0.001) for both radiation protocols.Conclusions: Directly induced radiation leads to potential damage of hard dental tissues, which can be further damaged by additional bleaching. If teeth whitening is necessary after irradiation, it is suggested to use lower concentrations of whitening gels.
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