Inadequate isolation of the operative field Absolute isolation is indicated to reduce two issues that cause post-operative sensitivity generated by penetration of saliva into the operative field: contamination of the cavity by microorganisms that cause pulp inflammation and contamination by humidity, which harms the bond and facilitates marginal leakage (4). The study of Auschill et al. (8) showed that the type of isolation, with a rubber dyke or cotton wool rolls, has no influence on the occurrence of post-operative pain, provided that cavity contamination is avoided.