Influência da morfologia da junção amelocementária (JAC) nas alterações de pH extrarradicular associadas ao clareamento intracoronário
Influence of cementoenamel junction morphology (CEJ) on the extraradicular pH alterations associated with intracoronal bleaching
Bernardineli, Norberti; Bodanezi, Augusto; Bramante, Clovis Monteiro; Garcia, Roberto Brandão; Moraes, Ivaldo Gomes de
Rev. odontol. UNESP, vol.38, n5, p.286-290, 2009
Abstract
Este estudo longitudinal investigou o efeito da ausência de junção amelocementária (JAC) na variação de pH extrarradicular durante clareamento interno. Dividiram-se 30 incisivos humanos extraídos em dois grupos experimentais (n = 12) e um grupo controle (n = 6). Nos espécimes do grupo experimental I, as junções amelocementárias foram mantidas intactas; no grupo experimental II, as mesmas foram completamente removidas por desgaste com ponta diamantada antes da inserção intracoronária de peróxido de hidrogênio a 30% (Magistral Pharma). No grupo controle, as câmaras pulpares foram repletas de soro fisiológico. Em cada intervalo experimental de 0, 24, 72, 96, 156, 192 e 270 horas, mensurava-se o pH extrarradicular por meio da sonda de um peagômetro (Micronal®) inserida na água destilada em que os espécimes eram imersos e, imediatamente, o agente clareador era renovado. A análise de variância a dois critérios revelou para o grupo II (JAC ausente) os menores valores de pH (4,3 ± 0,16), estatisticamente diferentes do grupo controle (7,1 ± 0,20) nos intervalos de 156, 192 e 270 horas, e do grupo I (5,9 ± 0,14) no período de 270 horas (p ≤ 0,05). Concluiu-se que a ausência de união entre cemento e esmalte intensificou a redução de pH no meio extrarradicular somente após 270 horas de clareamento interno.
Keywords
Colo do dente, clareamento de dente, peróxido de hidrogênio, reabsorção
de dente.
Resumo
This longitudinal study investigated the effect of cementoenamel junction (CEJ) absence on the extraradicular pH variation during intracoronal bleaching. Thirty extracted human incisors were divided into two experimental groups (n=12) and a control (n=6). In specimens of group I the cementoenamel junctions were kept original whereas in group II they were completely removed through cut using a diamond bur prior the intracoronal insertion of 30% hydrogen peroxide (Magistral Pharma). For the control group the pulp chambers were filled with saline. In the experimental intervals of 0, 24, 72, 96, 156, 192 and 270 hours the extraradicular pH was measured by means of a pH meter (Micronal®) probe inserted in the distilled water in which the specimens were immersed, and soon afterwards the bleaching agent was renewed. The two-way analysis of variance revealed the lowest pH levels for group II (4,3±0,16) which were statistically different from that of control group (7,1±0,20), at the intervals of 156, 192 and 270 hours, and from that of group I (5,9±0,14) at 270 hours (p≤0.05). It was concluded that the absence of cementoenamel junction intensified the extraradicular decrease of pH only after 270 hours of intracoronal bleaching.
Palavras-chave
Cementoenamel junction, tooth bleaching, hydrogen peroxide, tooth resorption
References
1. Tredwin CJ, Naik S, Lewis NJ, Scully C. Hydrogen peroxide tooth-whitening (bleaching) products: review of adverse effects and safety issues. Br Dent J. 2006;200:371-6.
2. Lee GP, Lee MY, Lum SOY, Poh RSC, Lim K-C. Extraradicular diffusion of hydrogen peroxide and pH changes associated with intracoronal bleaching of discoloured teeth using different bleaching agents. Int End J. 2004;37:500-6.
3. Lim MY, Lum SO, PoH RS, Lee GP, Lim KC. An in vitro comparison of the bleaching efficacy of 35% carbamide peroxide with established intracoronal bleaching agents. Int End J. 2004;37:483-8.
4. Gökay O, Ziraman F, Cali Asal A, Saka OM. Radicular peroxide penetration from carbamide peroxide gelss during intracoronal bleaching. Int End J. 2008;41:556-60.
5. Nutting EB, Poe GS. A new combination for bleaching teeth. J S Calif State Dent Assoc. 1963;31:289-91.
6. Friedman S, Rotstein I, Libfeld H, Stabholz A. Heling I. Incidence of external root resorption and esthetic results in 58 bleached pulpless teeth. Endod Dent Traumatol. 1988;4:23-6.
7. Wang JD, Hume WR. Diffusion of hydrogen ion and hydroxyl ion from various sources through dentine. Int End J. 1988; 21:17-26.
8. Dezotti MSG, Silva e Souza Júnior MH, Nishiyama CK. Evaluation of pH variation and cervical dentin permeability in teeth submitted to bleaching treatment. Pesqui Odontol Bras. 2002;16:263-8.
9. Jiang T, Ma X, Wang Y, Zhu Z, Tong H, Hu J. Effects of hydrogen peroxide on human dentin structure. J Dent Res. 2007;86:1040-5.
10. Koulaouzidou E, Lambrianidis T, Beltes P, Lyroudia K, Papadopoulos C. Role of cementoenamel junction on the radicular penetration of 30% hydrogen peroxide during intracoronal bleaching in vitro. Endod Dent Traumatol. 1996;12:146-50.
11. Neuvald L, Consolaro A. Cementoenamel junction: microscopic analysis and external cervical resorption. J Endod. 2000;26:503-8.
12. Esberard R, Esberard RR, Esberard RM, Consolaro A, Pameijer CH. Effect of bleaching on the cemento-enamel junction. Am J Dent. 2007;20:245-9.
13. Kinomoto Y, Carnes DL, Ebisu S. Cytotoxicity of intracanal bleaching agents on periodontal ligament cells in vitro. J Endod. 2001;27:574-7.
14. Outhwaite WC, Livingston MJ, Pashley DH. Effects of changes in surface area, thickness, temperature and post-extraction time on human dentine permeability. Arch Oral Biol. 1976;21:599-603.
15. Bosshardt DD, Selvig KA. Dental cementum: the dynamic tissue covering of the root. Periodontol 2000. 1997;13(2):41-75.
16. Rotstein I, Torek Y, Misgav R. Effect of cementum defects on radicular penetration of 30% H2O2 during intracoronal bleaching. J Endod. 1991;17: 230-3.
17. Heithersay GS. Invasive cervical resorption: analysis of potential predisposing factors. Quintessence Int. 1999;30:83-95.
18. Camps J, de Franceschi H, Idir F, Roland C, About I. Time-course diffusion of hydrogen peroxide through human dentin: a clinical significance for young tooth internal bleaching. J Endod. 2007;33:455-9.
19. Rotstein I. In vitro determination and quantification of 30% hydrogen peroxide penetration through dentin and cementum during bleaching. Oral Surg Oral Med Oral Patol. 1991;72:602-6.
20. Valera MC, Camargo CHR, Teixeira AU, Camargo SEA. Microinfiltração de materiais restauradores temporários usados durante o clareamento dental interno. Cienc Odontol Bras. 2007;10:26-31.
21. Oliveira LD, Carvalho CAT, Hilgert E, Bondioli IR, Araújo MAM, Valera MC. Sealing evaluation of the cervical base in intracoronal bleaching. Dent Traumatol. 2003;19:309-13.
22. Llena C, Amengual J, Forner L. Sealing capacity of a photochromatic flotable composite as protective base in nonvital dental bleaching. Int End J. 2006;39(3):185-9.
23. Puapichartdumrong P, Ikeda H, Suda H. Influence of the pulpal components on human dentine permeability in vitro. Int End J. 2005;38:152-9.
24. Pashley DH, Livingston MJ, Greenhill JD. Regional resistance to fluid flow in human dentin, in vitro. Arch Oral Biol. 1978;23:807-10.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email