Hypersensitivity induced by non-surgical periodontal treatments. Protective effects of oxalate-phytocomplexes

OBJECTIVES: To examine the effects of a new oxalate-containing phytocomplex spray in preventing dentin tubules exposure after application of citric acid following mechanical root instrumentation.

METHODS: Thirty recently extracted human teeth were used to obtain root dentinal blocks 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 group was further divided in three sub-groups (Control, Acid attack and Phytocomplex+Acid). The control group specimens were immersed in distilled water buffered to pH 7.4. The specimens 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 Phytocomplex+Acid subgroup were sprayed for 15 sec with a 15% phytocomplex solution prior to immersion into citric acid solution. The specimens were examined using SEM technique.

RESULTS: Ultrasonic instrumentation created a very thin smear layer whereas curettes produced a multi-layered and compact smear layer. The acidic solution removed 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 use of the phytocomplex solution prevented dentinal tubules exposure.

CONCLUSION: Acidic solutions may remove the smear layer created on root surfaces by mechanical root instrumentation. However, the smear layer and the smear plugs created by hand instrumentation appeared to be more resistant to acid attack. The tested phytocomplex solution protected the dentin from demineralization and it might prevent post-treatment dentinal hypersensitivity induced by acidic solutions.