The effect of dentine-bonding agents on substance P release in human dental pulp J. Caviedes-Bucheli 1 , J. A. Correa-Ortiz 2 , A. C. Ballestero 1 , M. Jimenez 1 , A. Munoz 1 , C. Rivero 1 , N. Lombana 3 & H. R. Munoz 4 1 Endodontic Department, School of Dentistry, Pontificia Universidad Javeriana; 2 Oral Rehabilitation Department, School of Dentistry, Pontificia Universidad Javeriana; 3 Chemistry Department, Universidad de Los Andes, Bogota ´, Colombia; and 4 Postgraduate Endodontic Department, School of Dentistry, Universidad de San Carlos, San Carlos, Guatemala Abstract Caviedes-Bucheli J, Correa-Ortiz JA, Ballestero AC, Jimenez M, Munoz A, Rivero C, Lombana N, Munoz HR. The effect of dentine-bonding agents on substance P release in human dental pulp. International Endodontic Journal, 43, 95–101, 2010. Aim To quantify the effect of dentine-bonding agents on Substance P (SP) release in healthy human dental pulp tissue. Methodology Forty pulp samples were obtained from healthy pre-molars where extraction was indi- cated for orthodontic reasons. In thirty of these pre- molars, a standardized Class V cavity preparation was performed, and teeth were divided equally into three groups: (i) Unetched-cavity control group: Class V cavities only; (ii) Experimental Group I: ‘One-step’ self- etch bonding agent was placed in the cavity; and (iii) Experimental Group II: ‘Two-step’ total-etch bonding agent was placed in the cavity. The remaining ten healthy pre-molars where extracted without treatment and served as an intact-teeth control group. SP was measured by radioimmunoassay. Results Greater SP release was found in the ‘one- step’ bonding agent group, followed by the ‘two-step’ bonding agent group and the unetched-cavity control group. The lower SP values were for the intact-teeth control group. anova showed statistically significant differences between groups (P = 0.0001). Tukey HSD post hoc tests showed statistically significant differ- ences in SP release between the intact-teeth control group and the three other groups (P < 0.01) and between the unetched-cavity control group and the ‘one-step’ bonding agent group (P < 0.05). No sig- nificant difference was found between the ‘two-step’ bonding agent and the unetched-cavity control group. Conclusion Dentine-bonding agents placed over Class V cavity preparations increased SP release. One-step dentine-bonding agents increased SP release most. Keywords: cavity preparation, dentine-bonding agents, human dental pulp, neuropeptides, substance P. Received 27 March 2009; accepted 5 October 2009 Introduction Neuropeptides play a significant role in the neuronal response of the pulp that control local perfusion changes (Kim 1990). They are present in the sensory afferent neurons from the trigeminal ganglia and in sympathetic fibres from the cervical ganglia (Wakisaka & Akai 1989, Wakisaka 1990). Substance P (SP) plays a major role in neurogenic inflammation by inducing vasodilation, increasing pulpal blood flow (PBF), and therefore, allowing the arrival of a considerable amount of inflammatory cells and the release of inflammatory mediators into the injury site, such as histamine, cytokines and prosta- glandins, generating tissue oedema and an increase in the interstitial pressure (Caviedes-Bucheli et al. 2008). Pulp tissue undergoes several alterations during neurogenic inflammation, including: sensitization of Correspondence: Javier Caviedes-Bucheli, DDS, MSc. School of Dentistry, Pontificia Universidad Javeriana, Cra 7 No. 40-62 Building 26, Bogota, Colombia (Tel.: +57 (1) 3208320 Ext. 2889; e-mail: javiercaviedes@cable.net.co). doi:10.1111/j.1365-2591.2009.01646.x ª 2010 International Endodontic Journal International Endodontic Journal, 43, 95–101, 2010 95