Authors: Baumgartner JC, Reid DE, Pickett AB.
Title: Human pulpal reaction to the modified McInnes bleaching technique.
Journal: J Endod
Date: Dec 1983
Citation: 9(12):527-9
Category: Bleaching/Tooth Whitening
Evidence-based Ranking: 2
Purpose/Objectives: To determine histologically the effects of this technique on the pulp. Materials & Methods: Nine patients, each with four caries-/restoration-/stain-free premolars that were scheduled for extraction for orthodontic purposes were used in the study. One maxillary and one mandibular premolar were treated with the Modified McInnes Bleaching Technique and the contralateral premolars served as controls. For each patient, tooth vitality was verified and radiographs were taken prior to beginning the treatment and all teeth were determined to be WNL. All teeth in the study were cleaned and polished with pumice and water. Teeth were isolated with rubber dam. The test teeth were treated with mixture of 1 ml 36% hydrochloric acid, 1 ml of 30% hydrogen peroxide and 0.2 ml of diethyl ether. The mixture was applied to the facial surface of each test tooth with a cotton applicator for 5 minutes. Control teeth had saline applied to the facial surface. Next a fine cuttle disk was used with very light pressure on the treated and the control teeth for 15 seconds. This process was repeated 2 times resulting in application of the bleaching mixture or saline for a total of 15 minutes and application of the cuttle disk for 45 seconds. At intervals of 1,3,5,7,9,11,13,17 and 19 days, four teeth from the same candidate were extracted. The pulp tissue was fixed, teeth were decalcified and examined microscopically for amount of cellular displacement, superficial and deep inflammatory response. These factors were graded as mild, moderate or severe.

Results: Results showed that of the 36 teeth treated, 25 pulps (12 control and 13 treated) showed no pulpal changes, 6 control and 5 treated teeth had mild to moderate pulpal inflammation and no teeth exhibited severe inflammation.

AuthorsÂ’ Conclusions: Microscopic examination of teeth treated with this bleaching technique revealed no significant pulpal reaction, even when a substantial amount of enamel was removed from the facial surface of the crowns.

Validity of Conclusions: Conclusions appear valid based on the scope of the study.

ReviewerÂ’s Comments: This article reviews a technique of external bleaching, intended to be used to remove stain in cases of endemic dental fluorosis. The article shows that in treating the teeth as done here (application of the acid solution for a total of 15 minutes and disking for a total of 45 seconds) a significant amount of enamel can be removed. Because of this, if ever using this technique, caution should be used to not remove too much enamel.