Tooth brushing one they feel comfortable with, determine what is affordable for them and will be more likely to regularly brush with. Toothbrushes are offered with varying textures of bristles, and come in many different forms and sizes. Most dentists recommend using a toothbrush labelled "soft", since firmer bristled toothbrushes can damage tooth enamel and irritate gums as indicated by the American Dental Association. Toothbrushes are often made from synthetic fibers, although natural toothbrushes are also known in many parts of the world. Those with dentures may also brush their teeth with traditional tooth brushes, specially made denture brushes or denture cleaners.
Smear layer Smear layer The smear layer is a layer of microcrystalline and organic particle debris that is found spread on root canal walls after root canal instrumentation. It was first described in 1975 and much research has been performed since then to evaluate its importance in assisting or preventing the penetration of bacteria into the dentinal tubules. More broadly, it is the organic layer found over all hard tooth surfaces. Early studies of dentinal walls after cavity preparation performed by Brännström and Johnson (1974) showed the presence of a thin layer of debris that was 2 to 5 micrometres thick. In