Objective: The aim of this study was to investigate the different smear layer morphologies produced by instrumentation with a hand curette and a periodontal sonic scaler for potential removal by soft acidic solution. The effect of a new oxalate-containing phytocomplex spray in preventing tubules exposure after citric acid solution application was also evaluated. Methods: Thirty recently extracted human teeth were used to obtain root dentinal fragments and divided in two groups: Curette treatment (CRT) root planed applying 30 working strokes to each surface using a Gracey?s curette 5-6 and Ultrasonic scaler (USC) treated using a periodontal scaler mounted on an ultrasonic hand-piece for 30 seconds. Each principal group was further divided in three sub-groups (Control, Acid challenge and Acid/Phyto-oxalate). The control group samples were immersed in distilled water buffered to pH 7.4 using NH4 OH solution. The samples of the acid challenge group were immersed in a solution of citric acid 0,02M; [pH 2.5] for 3 minutes. The samples of the Acid/Phyto-oxalate group were sprayed for 15 sec with a 1.5% phytocomplex spray prior to immersion. Samples were examined using SEM. Results: Ultrasonic instrumentation created a very thin smear layer whereas curettes produced a multilayered smear layer. The acidic solution was able to remove the smear layer from root surfaces treated with ultrasonic instrumentation exposing the dentinal tubules. The smear layer on the root surfaces treated with hand instruments was not completely removed. The phytocomplex solution was able to prevent dentinal tubule exposure. Conclusions: Acidic soft drinks are able to remove the smear layer created on root surfaces during different non-surgical periodontally treatments. The smear plugs created by hand instrumentation appeared to be more resistant to acid attack. The tested phytocomplex solution protected the dentine from demineralization and it might prevent post-treatment dentinal hypersensitivity induced by acidic soft drinks.