The Influence of Dentine on the pH of Calcium Hydroxide, Chlorhexidine Gel, and Experimental Bioactive Glass-Based Root Canal Medicament.
OBJECTIVE
To evaluate the influence of dentine on the pH of different medications in standardized simulated canals.


METHODS
Forty resin blocks were divided into groups with and without dentine powder, as follows: 2% chlorhexidine gel; 2% chlorhexidine gel associated with calcium hydroxide PA; calcium hydroxide PA delivered in propylene glycol 600; and NPG delivered in distilled water. The dentine powder was obtained from the root dentine of bovine teeth and added to the medications. The simulated canals were placed in containers with 1.5 mL of deionized water and pH was monitored in multiple intervals, up to 30 days. The mean pH values were calculated and submitted to statistical analysis using paired Student's t-test and ANOVA complemented by the Tukey test (p < 0.05).


RESULTS
There was no statistical difference between the groups with and without dentine powder (p > 0.05). The pH values of calcium hydroxide were significantly higher than those of NPG in the first 24 hours (p < 0.05). After 7 days, both behaved in a similar manner.


CONCLUSIONS
The addition of dentine powder to the medications evaluated did not alter the pH of the external solution in any of the time points tested.
University Ceuma, Rua Josué Montello No. 1, Renascença II, 65075-120 São Luís, MA, Brazil ; School of Dentistry, University of São Paulo, Department of Restorative Dentistry, Endodontics Division, Avenida Prof. Lineu Prestes 2227, 05508-000 São Paulo, SP, Brazil.
Ceci Nunes
CN
Carvalho
School of Dentistry, University of São Paulo, Department of Restorative Dentistry, Endodontics Division, Avenida Prof. Lineu Prestes 2227, 05508-000 São Paulo, SP, Brazil.
Laila Gonzales
LG
Freire
School of Dentistry, University of São Paulo, Department of Restorative Dentistry, Endodontics Division, Avenida Prof. Lineu Prestes 2227, 05508-000 São Paulo, SP, Brazil.
Alexandre Pinheiro Lima
AP
de Carvalho
School of Dentistry, University of São Paulo, Department of Restorative Dentistry, Endodontics Division, Avenida Prof. Lineu Prestes 2227, 05508-000 São Paulo, SP, Brazil.
Evandro Luiz
EL
Siqueira
Department of Dentistry I, School of Dentistry, University Federal of Maranhão (UFMA), Avenida dos Portugueses, s/n, 65085-680 São Luís, MA, Brazil.
José
J
Bauer
University Ceuma, Rua Josué Montello No. 1, Renascença II, 65075-120 São Luís, MA, Brazil.
Giovana Cunha
GC
Gritti
Center of Materials Science and Technology, Energy and Nuclear Research Institute (IPEN), Avenida Lineu Prestes 2242, Cidade Universitaria, 05588-900 São Paulo, SP, Brazil.
Juliana Pereira
JP
de Souza
School of Dentistry, University of São Paulo, Department of Restorative Dentistry, Endodontics Division, Avenida Prof. Lineu Prestes 2227, 05508-000 São Paulo, SP, Brazil.
Giulio
G
Gavini
D000818:Animals; D002126:Calcium Hydroxide / Q000737:chemistry*; D002417:Cattle; D002710:Chlorhexidine / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000601:surgery; D003804:Dentin / Q000737:chemistry*; D005782:Gels; D005898:Glass / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007180:Incisor / Q000601:surgery; D008953:Models, Anatomic; D009556:Niobium / Q000737:chemistry; D019946:Propylene Glycol / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation / Q000379:methods
D005782:Gels; D012388:Root Canal Irrigants; D009556:Niobium; D019946:Propylene Glycol; D002126:Calcium Hydroxide; D002710:Chlorhexidine