This study investigates how, through digital radiography, the averages in gray levels are expressed in different sites of teeth restored with composite resins in varying thicknesses and what the possible reasons are for the values found. This study comprises a selection of ten healthy first premolars whose roots were embedded in prisms with rectangular bases, then radiographed according to standard procedure by using DenOptix digital optic plates, and whose were digitalized and filed for further analysis. Such samples formed group 1. Each time those teeth received some type of treatment which altered their original shape, a new group was formed. The teeth underwent a standard cavity preparation with a 2mm B-P thickness and were radiographed one more time. Their images were filed, thus forming group 2. The cavities were then restored with Filtek™Z350 composite resins and the teeth were radigraphed again and their digital images filed, thus forming group 3. Such restorations were then removed from their corresponding cavities and the teeth were restored one more time with 4Seasons resin, later radiographed, and their digital images were filed, thus forming group 4. After the restorations were removed, the cavities they once filled were restored with Filtek™Z250 resin. The radiography and filing steps were repeated one more time, thus forming group 5. After the restorations were removed, the cavities’ V-P widths were enlarged by 3mm, and the same steps applied to the previous groups were repeated, thus forming groups 6, 7, 8 and 9. After the removal of the restorations from group 9, the cavities’ V-P widths were enlarged by 4mm, and the same procedures applied to the previous groups were repeated, thus forming four new groups: 10, 11, 12 and 13.Thirty acrylic plates were also manufactured whose thicknesses varied between 2, 3 and 4mm, ten plates of each thickness – each plate contained one sample of each resin. The digital images of plates forming groups 14, 15 and 16, Este trabalho teve como objetivo verificar, através da radiografia digital, como se expressam os valores médios, em níveis de cinza, em diferentes sítios de dentes restaurados com resinas compostas em diversas espessuras e quais as possíveis justificativas para tais valores encontrados. Para tanto foram selecionados 10 primeiros pré-molares hígidos, que tiveram suas raízes incluídas em prismas de base quadrangular, sendo radiografados por técnica padronizada utilizando placas ópticas do sistema digital DenOptix, as quais foram digitalizadas e arquivadas para posterior análise. Estas constituíram o grupo 1. Cada vez que estes dentes recebessem algum tratamento, que alterasse a sua forma original, se constituiria um novo grupo. Os dentes passaram por preparo cavitário padronizado com espessura V-P de 2mm, foram novamente radiografados e as imagens digitais arquivadas, constituindo o grupo 2. As cavidades foram restauradas com resina composta Filtek™Z350, os dentes foram novamente radiografados e as imagens digitais arquivadas, constituindo o grupo 3. Essas restaurações foram destacadas das cavidades e os dentes novamente restaurados com a resina 4Seasons, radiografados e as imagens digitais arquivadas, constituindo grupo 4. Após as restaurações serem destacadas, essas cavidades foram mais uma vez restauradas, agora com a resina Filtek™Z250, repetindo-se as radiografias e o arquivamento das imagens digitais, constituindo o grupo 5. Após a remoção dessas restaurações as cavidades foram ampliadas na largura V-P para 3mm, repetindo-se a mesma seqüência realizada nos grupos anteriores, constituindo os grupos 6, 7, 8 e 9. Após a remoção das restaurações do grupo 9, as cavidades foram ampliadas na largura V-P para 4mm, repetindo-se a seqüência realizada nos grupos anteriores, constituindo novos grupos: 10, 11, 12 e 13.Também foram confeccionadas 30 placas acrílicas nas espessuras de 2, 3 e 4mm, 10 placas em cada uma das espessuras, sendo que as placas continham uma amostra d