The effect of radiation therapy on the mechanical and morphological properties of the enamel and dentin of deciduous teeth—an in vitro study

Mellara, Talitha de Siqueira; Palma-Dibb, Regina Guenka; Oliveira, Harley Francisco de; Paula-Silva, Francisco Wanderley Garcia; Filho, Paulo Nelson; Silva, Léa Assed Bezerra da; Queiroz, Alexandra Mussolino de

doi:10.1186/1748-717x-9-30

Cited by 70 publications

(102 citation statements)

References 24 publications

(58 reference statements)

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“…In this regard, a previous follow-up study demonstrated that radiotherapy changed salivary properties and reduced the salivary flow and buffering capacity of individuals with Hodgkin's disease [Marangoni-Lopes et al, 2016]. Although the present study does not represent a real clinical condition of postradiation in the oral environment, we used a representative sample size and were able to demonstrate changes occurring in primary enamel and dentin, even at doses lower than those used previously [de Siqueira Mellara et al, 2014;de Sá Ferreira et al, 2016].…”

Section: Discussionmentioning

confidence: 84%

“…In this way, it would be relevant to investigate how the enamel and dentin of primary teeth behave under radiotherapy. A recent study [de Siqueira Mellara et al, 2014] showed that the transverse microhardness of enamel decreased at a dose of 6,000 cGy, whereas the values of dentin microhardness did not change. When one considers that the lower the microhardness, the lower the mineral content, another important aspect to be investigated is the mineral composition of irradiated enamel and dentin.…”

Section: Introductionmentioning

confidence: 99%

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Radiotherapy Reduces Microhardness and Mineral and Organic Composition, and Changes the Morphology of Primary Teeth: An in vitro Study

et al. 2018

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Objective: We aimed to evaluate whether radiotherapy causes changes in the mineral composition, hardness, and morphology of enamel and dentin of primary teeth. Materials and Methods: Thirty specimens of primary teeth were subjected to radiotherapy. At baseline and after 1,080, 2,160, and 3,060 cGy, the specimens were subjected to microhardness, FT-Raman spectroscopy, and scanning electron microscopy (SEM) analysis. The pH of artificial saliva was determined, as were the calcium and phosphate concentrations. The data were subjected to the Shapiro-Wilk normality test, showed a nonnormal distribution, and were compared by the Kruskal-Wallis test. Results: The results showed that the microhardness of the enamel surface decreased after 2,160 cGy (281.5 ± 58 kgf/mm²) when compared to baseline (323.6 ± 59.5 kgf/mm²) (p = 0.045). For dentin, the surface hardness decreased after 1,080 cGy (34.9 ± 11.4 kgf/mm²) and 2,160 cGy (26 ± 3.5 kgf/mm²) when compared to baseline (56.5 ± 7.7 kgf/mm²) (p < 0.0001). The mineral and organic contents of phosphate (p < 0.0001), carbonate (p < 0.0001), amide (p = 0.0002), and hydrocarbons (p = 0.0031) of enamel decreased after 3,060 cGy (5,178 ± 1,082, 3,868 ± 524, 999 ± 180, and 959 ± 168 kgf/mm², respectively). For dentin, we noticed a growing increase in phosphate v2, amide, and hydrocarbon content after 1,080 cGy (8,210 ± 2,599, 5,730 ± 1,818, and 6,118 ± 1,807 kgf/mm², respectively) and 2,160 cGy (1,0071 ± 2,547, 7,746 ± 1,916, and 8,280 ± 2,079 kgf/mm², respectively) and a reduction after 3,060 cGy (6,782 ± 2,175, 3,558 ± 1,884, and 3,565 ± 1,867 kgf/mm², respectively) (p < 0.0001). SEM images showed cracks on enamel and degradation of peritubular dentin. Conclusion: We concluded that radiotherapy caused a reduction in surface hardness, changed mineral and organic composition, and promoted morphological changes on the enamel and dentin of primary teeth.

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Section: Discussionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Radiotherapy Reduces Microhardness and Mineral and Organic Composition, and Changes the Morphology of Primary Teeth: An in vitro Study

et al. 2018

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“…However, previous in vitro studies have shown controversial enamel microhardness and micromorphological results following radiotherapy [Soares et al, 2010;de Siqueira Mellara et al, 2014;Gonçalves et al, 2014]. This could be due to the fact that these studies were performed in sound teeth submitted to simulated radiotherapy, which does not represent the real clinical conditions of a postradiation oral environment.…”

mentioning

confidence: 70%

Structural Analysis of Enamel in Teeth from Head-and-Neck Cancer Patients Who Underwent Radiotherapy

Madrid

Paglioni²,

Line³

et al. 2017

Caries Res

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Objective: To analyze macroscopic, microscopic, and ultrastructural aspects of enamel from head-and-neck cancer patients submitted to radiotherapy. Materials and Methods: Twenty sound extracted permanent molars were used and divided into 2 groups. The experimental group consisted of 10 molars from head-and-neck cancer patients submitted to radiotherapy with total doses that ranged from 50 to 70 Gy. Ten molars from patients who did not receive radiotherapy were matched with experimental-group samples by anatomic tooth group and comprised the control group. To perform a macroscopic analysis, standardized photos of different enamel faces were taken with a camera. Teeth were subjected to longitudinal cuts and hand polished to a final thickness of 0.1 mm. Enamel was analyzed under polarized light microscopy, and optical retardation values of birefringence were calculated in cervical, cusp, and occlusal pit areas. Subsequently, the same enamel areas were analyzed by scanning electron microscopy. Data from optical retardation values were statistically analyzed by 2-way ANOVA and Fisher's test (α < 0.05). Results: No macroscopic differences were observed between the irradiated and control groups. Polarized light microscopy analysis revealed that cervical enamel exhibited darker areas characterized by discrete birefringence patterns compared to the control enamel. Optical retardation values were only significantly different in the cervical enamel of the irradiated and control groups (p < 0.0001). Scanning electron microscopy analysis revealed more evident interprismatic spaces in the cervical and outer cusp enamel of irradiated samples. Conclusions: Head-and-neck radiotherapy reduced optical retardation values of birefringence in cervical enamel, and the interprismatic spaces became more evident.

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“…In the past, severely decayed teeth were frequently extracted prior to radiotherapy, but more recently, the teeth are submitted to root canal treatment to prevent tooth extraction (10). The modifications of the mechanical properties of dentin caused by radiotherapy are confirmed by several studies (2,11,12). However, the additional effect caused by the endodontic therapy performed in radiated teeth remains unknown.…”

Section: Introductionmentioning

confidence: 99%

Effect of Gamma Radiation and Endodontic Treatment on Mechanical Properties of Human and Bovine Root Dentin

et al. 2016

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This study evaluated the effect of gamma radiation and endodontic treatment on the microhardness and flexural strength of human and bovine root dentin. Forty singlerooted human teeth and forty bovine incisor teeth were collected, cleaned and stored in distilled water at 4 °C. The human and bovine teeth were divided into 4 groups (n=10) resulting from the combination of two study factors: first, regarding the endodontic treatment in 2 levels: with or without endodontic treatment; and second, radiotherapy in two levels: with or without radiotherapy by 60 Gy of Co-60 gamma radiation fractioned into 2 Gy daily doses five days per week. Each tooth was longitudinally sectioned in two parts; one-half was used for the three-point bending test and the other for the Knoop hardness test (KHN). Data were analyzed by 3-way ANOVA and Tukey HSD test (α=0.05). No significant difference was found for flexural strength values. The human dentin had significantly higher KHN than the bovine. The endodontic treatment and radiotherapy resulted in significantly lower KHN irrespective of tooth origin. The results indicated that the radiotherapy had deleterious effects on the microhardness of human and bovine dentin and this effect is increased by the interaction with endodontic therapy. The endodontic treatment adds additional negative effect on the mechanical properties of radiated tooth dentin; the restorative protocols should be designed taking into account this effect. E f f e c t o f G a m m a R a d i a t i o n a n d E n d o d o n t i c T r e a t m e n t o n M e c h a n i c a l P r o p e r t i e s o f

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The effect of radiation therapy on the mechanical and morphological properties of the enamel and dentin of deciduous teeth—an in vitro study

Cited by 70 publications

References 24 publications

Radiotherapy Reduces Microhardness and Mineral and Organic Composition, and Changes the Morphology of Primary Teeth: An in vitro Study

Radiotherapy Reduces Microhardness and Mineral and Organic Composition, and Changes the Morphology of Primary Teeth: An in vitro Study

Structural Analysis of Enamel in Teeth from Head-and-Neck Cancer Patients Who Underwent Radiotherapy

Effect of Gamma Radiation and Endodontic Treatment on Mechanical Properties of Human and Bovine Root Dentin

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