In-office bleaching effects on the pulp flow and tooth sensitivity – case series

Abstract

Laser Doppler flowmetry (LDF) is a noninvasive method capable of evaluating variations in pulp blood flow (PBF) and pulp vitality. This method has thus far not been used to assess changes in blood flow after in-office bleaching. The aim of this case series report was to measure changes in PBF by LDF in the upper central incisor of three patients submitted to in-office bleaching. The buccal surfaces of the upper arch were bleached with a single session of 35% hydrogen peroxide gel with three 15-min applications. The color was recorded using a value-oriented Vita shade guide before in-office bleaching and one week after the procedure. The tooth sensitivity (TS) in a verbal scale was reported, and PBF was assessed by LDF before, immediately, and one week after the bleaching session. The lower arch was submitted to dental bleaching but not used for data assessment. A whitening degree of 3 to 4 shade guide units was detected. All participants experienced moderate to considerable TS after the procedure. The PBF readings reduced 20% to 40% immediately after bleaching. One week postbleaching, TS and PBF were shown to be equal to baseline values. A reversible decrease of PBF was detected immediately after bleaching, which recovered to the baseline values or showed a slight increase sooner than one week post-bleaching. The LDF method allows detection of pulp blood changes in teeth submitted to in-office bleaching, but further studies are still required.

A novel approach for in-office tooth bleaching with 6 % H2O2/TiO_N and LED/laser system—a controlled, triple-blinded, randomized clinical trial

“…Although a hard tissue, enamel has pores that allow the penetration of hydrogen peroxide [29], which causes the release of inflammatory mediators that can sensitize or depolarize nociceptors that innervate the pulp tissue [30]. Recently, it has been shown that this inflammatory reaction also reduces the pulp blood flow [31]. According to Markowitz [26], the reason that most patients experience a pain as a Btwingeô r a Bshock^with no stimulus is because oxidant agents, as higher concentration of hydrogen peroxide, stimulate nociceptive afferents leading to sensitivity and inflammation.…”

Analysis of the Color and Fluorescence Alterations of Enamel and Dentin Treated With Hydrogen Peroxide

“…Hydrogen peroxide can be applied directly on tooth, diffuse trough tooth enamel to reach the enamel-dentinal junction and dentine regions (11)(12)(13). In alkaline conditions, hydrogen peroxide acts as a strong oxidizing agent forming free radicals that may eliminate chromophores by either cleaving double bonds in organic molecules or oxidizing their chemical moieties, resulting in soluble molecules (14).…”

Cytotoxic effects of hydrogen peroxide on periodontal cells

“…[1][2][3][4][5][6] While generally regarded as a safe agent for these applications, H 2 O 2 has a strong oxidant potential. Its effects in teeth and pulpal tissues have been well studied; [22][23][24][25][26][27] The results of our study showed, for the first time, that, in both the osteoblast and gingival fibroblast cell lines tested, exposure to a 0.05-µg/ml solution of H 2 O 2 (10-fold lower than the reportedly safe concentration of 0.68 µg/ml) elicited a cell-viability decrease of up to 50% (P<0.05), thus rejecting the first two null hypotheses. This effect was more pronounced with longer incubation times.…”