doi:10.1111/iej.12423 Tooth discolouration and internal bleaching after the use of triple antibiotic paste A. L. Kirchhoff1, D. P. Raldi2, A. C. Salles3, R. S. Cunha4 & I. Mello5 1Division of Endodontics, Pontificia Universidade Catolica do Parana, Curitiba; 2Department of Dentistry, University of Taubate, Taubate, Brazil; 3Division of Pediatric Dentistry, College of Dentistry, University of Manitoba, Winnipeg, MB; 4Division of Endodontics, College of Dentistry, University of Manitoba, Winnipeg, MB; and 5Division of Endodontics, Faculty of Dentistry, Dalhousie University, Halifax, NS, Canada Abstract TAP with a NaOCl rinse (T2) and after 1 (T3), 2 (T4) and 3 (T5) weeks of internal bleaching with sodium Kirchhoff AL, Raldi DP, Salles AC, Cunha RS, Mello I. perborate paste. Data were collected based on the CI- Tooth discolouration and internal bleaching after the use of ELAB-CIE1976 (L*a*b*) system and analysed using t- triple antibiotic paste. International Endodontic Journal, 48, tests and ANOVA. 1181–1187, 2015. Results A significant decrease in the mean values of Aim To assess the discolouration of teeth with closed L* (lightness) was observed after treatment with TAP and open apices after placement of triple antibiotic (T1, P < 0.05). Considerable increases in these values paste (TAP, ciprofloxacin, metronidazole and minocy- after bleaching with sodium perborate cline) in the pulp chamber and whether discolouration (T3 < T4 < T5) were found in both groups. The only could be reversed by internal bleaching procedures. significant difference in the intergroup analysis was Methodology Twenty extracted human mandibu- between T1 and T2, in which DE values in the OA lar premolars were divided into 2 groups (n = 10): group were higher (P = 0.04). teeth with closed apices (CA) and teeth with open api- Conclusions TAP discoloured the tooth structure, ces (OA). After conventional access, the TAP was but discolouration could be reversed with sodium per- sealed in the pulp chamber for 3 weeks. The paste borate paste. In general, teeth with closed and open was removed by a rinse with sodium hypochlorite apices had the same rates of discolouration and (NaOCl) and a mixture of sodium perborate and dis- bleaching. tilled water was sealed in the pulp chamber for 1, 2 Keywords: antibiotics, bleaching, discolouration, and 3 weeks. The shade was measured by a spectro- sodium perborate. photometer at six time periods: baseline (T0), after 3 weeks of placement of TAP (T1), after removal of Received 17 September 2014; accepted 11 December 2014 aggregate as an apical plug. Apexification permits dis- Introduction infection and filling of the root canal space with no Traditionally, the treatment of a tooth with an open further development of the root (Raldi et al. 2009). apex and a necrotic pulp was achieved with apexifica- Revascularization is a regenerative endodontic proce- tion procedures either with long-term use of calcium dure and a contemporary option for the same type of hydroxide or by placement of mineral trioxide cases. Restoration of the blood supply will take place, inducing continuing root development by deposition of hard tissue and resulting in thickening of the canal Correspondence: Isabel Mello, Division Head, Endodontics, walls, lengthening of the root, and apical closure Department of Dental Clinical Sciences, Dalhousie University, (Banchs & Trope 2004, Chueh & Huang 2006, Jung 5981 University Ave, PO Box 15000, Halifax, NS, B3H 4R2 et al. 2008, Chueh et al. 2009, Ding et al. 2009, Pe- (Tel.: (902) 494-2013; Fax: (902) 494-1662; e-mail: [email protected]). trino et al. 2010). © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd International Endodontic Journal, 48, 1181–1187, 2015 1181 Internal bleaching after using triple antibiotic paste Kirchhoff et al. Intracanal medicaments used in revascularization by TAP can be reversed by bleaching procedures and procedures vary and include calcium hydroxide, for- (iii) assess whether there is a difference in the pattern mocresol and pastes that combine antibiotics of discolouration and bleaching between teeth with (Moreno-Hidalgo et al. 2014). A triple antibiotic paste open and closed apices. (TAP, mixture of ciprofloxacin, metronidazole and mi- nocycline) has been proposed as one intracanal medi- Materials and methods cament to disinfect the root canal system for revascularization procedures (Hoshino et al. 1996, This study was approved by the Research Ethics Iwaya et al. 2001, Banchs & Trope 2004, Jung et al. Board of the University of Manitoba (H2014:106). 2008, Ding et al. 2009, Petrino et al. 2010). TAP is formed by mixing equal parts of all three antibiotics Sample selection in powder form with saline or sterile water. This paste is sealed in the canal for 3 weeks. One side effect of Twenty extracted human mandibular premolars (10 the use of the TAP is the discolouration of the tooth with closed apices and 10 with open apices) were structure and the crown in particular resulting in an used. All teeth were cleansed and then radiographed unaesthetic appearance (Kim et al. 2010, Dabbagh to verify the absence of resorption or previous end- et al. 2012, Lenherr et al. 2012). odontic treatment. Teeth identified with an open apex Discolouration of a root filled tooth can be had their apical foramen measured with a digital cal- improved by placing oxidizing agents in the pulp liper, and this diameter had to be >1.5 and <2.5 mm. chamber. In the walking bleach technique, an oxidiz- The teeth were sterilized in an autoclave and were ing agent is placed in the pulp chamber and sealed immersed in saline for hydration in individually for a period of time whilst whitening of the tooth is labelled bottles for 72 h. assessed. A common bleaching agent is sodium perbo- rate, a powder that when in contact with air or mois- Sample preparation ture gradually releases low levels of hydrogen peroxide, a main bleaching agent (Abbott & Heah The access opening was achieved, and all contents of 2009). the pulp chamber and coronal portion of the root Revascularization has emerged as a favourable canal were removed with a size 15 hand file (Dentsply treatment alternative, in particular for teeth that Tulsa Dental, Tulsa, OK, USA) and distilled water. A underwent pulp necrosis in the early stages of root cotton pellet was placed in the pulp chamber, and the formation. This treatment may result in root length- access preparation was sealed with Cavit (3M Espe, ening and increased dentine width, possibly decreas- MN, USA). ing the risk of tooth fracture (Thibodeau & Trope 2007, Shin et al. 2009). Although other medicaments Shade recording have been proposed for revascularization procedures, TAP seems to be used commonly (Diogenes et al. The samples were positioned in a plaster apparatus, 2013, Moreno-Hidalgo et al. 2014). The potential and a silicone impression was made over the teeth. conflict is that, although it should stay within the Perforations were made in the centre of the buccal root canal, TAP may come into contact with the pulp surface of the silicone impression to standardize the chamber and discolour the crown of the tooth, which procedure for shade recording. Shade recording of the will pose an aesthetic problem. Excellent results can crown was performed with a Vita Easyshade Advance be achieved with internal bleaching to correct intrin- 4.0 spectrophotometer (Vita Zahnfabrik H. Rauter sic tooth discolouration. The results may vary depend- GmbH & Co. KG, Bad Sackingen,€ Germany). This ing on the type of discolouration and length of time equipment quantifies the shade through a system that the tooth has been discoloured. To date, there is named CIELAB-CIE 1976 (L*a*b*) (Commission Inter- no research to verify whether the discolouration of nationale de L’Eclairage, Vienna, Austria) (Westland teeth treated with TAP can be improved by bleaching 2003). The L* value indicates lightness and varies procedures. between 0 for black and 100 for white; a* determines The aims of this study were to (i) confirm whether the amount of red (positive values) or green (negative tooth discolouration occurs when TAP is used as a values); and b* exhibits the amount of yellow (posi- medicament; (ii) verify whether discolouration caused tive values) or blue (negative values). 1182 International Endodontic Journal, 48, 1181–1187, 2015 © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd Kirchhoff et al. Internal bleaching after using triple antibiotic paste The shade was measured in the same room under another week, when the final shade was taken the same light by one calibrated operator at six differ- (T5 = total of 3 weeks of bleaching). ent time periods: baseline (T0), after 3 weeks of place- ment of TAP (T1), after rinsing out TAP with 2.5% Statistical analysis sodium hypochlorite (NaOCl) (T2), 1 week after place- ment of sodium perborate in the pulp chamber (T3), The data were analysed at 5% significance. The t-test 2 weeks after placement of sodium perborate in the was used to analyse intergroup data: the colour sta- pulp chamber (T4) and 3 weeks after placement of bility (DE) of the two experimental groups was com- sodium perborate in the pulp chamber (T5). At each pared at each time period. ANOVA complemented by time period, three measurements of L*,a* and b* the Tukey’s test were used for intragroup compari- were recorded and DL, Da and Db were then calcu- sons: lightness values at all time periods were com- lated by subtracting the final data from the initial pared within each experimental group. data within each time period. The constant difference in colour (DE) was then calculated using the follow- Results ing formula: DE = [(DL)2 + (Da)2 + (Db)2]1/2 (Friele- Max Adam-Chickering - Comission Internacionale de Discolouration was observed visually in all specimens L’Eclairage, 1976).