Bond strengths of two conventional glass-ionomer cements to irradiated and non-irradiated dentin

Abstract

This study evaluated the influence of irradiation on the dentin shear bond strength of two conventional glass ionomer cements (GICs). Thirty extracted molars were bisected in the mesio-distal direction. One-half of 20 teeth were irradiated with 60 Gy (5 days/week) for 6 weeks, and then GIC was placed on the irradiated dentin surface (Groups A1, B1). For the other halves of these tooth specimens, the GICs were first placed on their dentin surfaces and then the specimens irradiated (Groups A2, B2). The remaining 10 teeth were bisected and used as non-irradiated controls (Groups C1, C2). The GICdentin shear bond strengths were examined. Groups A2 and B2 had significantly lower bond strengths than groups A1, B1, C1, and C2 (p<0.05). No significant differences were found among groups A1, B1, C1, and C2 (p>0.05). In conclusion, irradiation may have an adverse effect on the bond strength of GICs depending on the application sequence.

Efeito da radioterapia com raios x de alta energia sobre a resistência de união da dentina humana com resina composta – estudo in vitro

“…No entanto, raios X de alta energia têm sido preconizados (8,13) porque geram fótons com maior energia, liberando uma dose menor para o paciente. O protocolo de dose radioterápica utilizado em pacientes que possuem câncer na região de cabeça e pescoço é de, aproximadamente, 70,2 Gy, fracionados em doses diárias de 1,8 Gy (180 cGy) ao dia, totalizando 39 aplicações (17,20,32).…”

“…Neste sentido, estudos têm avaliado o efeito da radioterapia sobre as propriedades mecânicas dos dentes (10)(11)(12)(13). Sua severidade e extensão sobre os tecidos dentais parecem ser dependentes do conteúdo mineral e orgânico das estruturas dentárias (10), que, após a irradiação, podem acomodar os radicais livres dentro da sua estrutura por longos períodos de tempo (14).…”

“…Permanece a incerteza em relação às possíveis alterações que ocorrem na dentina irradiada (12,18), pois os resultados desses estudos ainda não estão claros (13,17,18,21). Torna-se necessário estudos que sobre adesão em dentes irradiados, uma vez que não há consenso sobre o protocolo restaurador que deva ser realizado durante ou após o tratamento radioterápico (10), e, mais especificamente, o quanto os raios X de alta energia afetam a resistência de união entre dentina irradiada e resina composta.…”

Microtensile Bond Strength of Polyacid-modified Composite Resin to Irradiated Primary Molars

“…9 Studies investigating the effects of different doses of radiotherapy on restorative material bond strength in permanent teeth produced inconclusive results, with some researchers suggesting that radiotherapy increases bond strength, while others conclude that there is either a decrease or no change. [5][6][7] There are currently no published studies evaluating similar effects of radiotherapy on the bonding strength of restorative materials to deciduous teeth. In this study, we investigated the effect of radiation on the µTBS between compomer resin and primary tooth enamel and dentin.…”

“…Another study that evaluated permanent teeth reported that the application of a single radiotherapy dose of 60 Gy caused a reduction in the bond strength between glass ionomer cement and dentin. 7 However, the effects of radiation on the bonding strengths between compomer resin restorative materials widely used in deciduous teeth and enamel and dentin hard tissue in deciduous teeth have not been studied. The aim of this study was to evaluate the effects of various doses of radiation therapy (10-60 Gy) on the µTBS of compomer resin restorative materials to the enamel and dentin of primary molars and also to compare the…”