Antimicrobial activity and tightness of a DCPD-CaO-based hydraulic calcium phosphate cement for root canal filling.
Calcium hydroxide is currently used in dentistry for endodontic treatments where its main advantage is its antibacterial and anti-inflammatory activity. However, it also has some drawbacks such as pulp necrosis, slight solubility, slow and insufficient hardening, and retraction on drying. In consequence, it is used only as temporary material for root canal disinfection. By mixing calcium hydrogen phosphate dihydrate (CaHPO4 . 2H2O, also called dicalcium phosphate dihydrate, DCPD) and calcium oxide with a sodium phosphate buffer as liquid phase, we obtained a CPC with better mechanical properties than calcium hydroxide pastes. The setting reaction produced either hydroxyapatite (HA) or a mixture of HA and calcium hydroxide depending on the relative masses of DCPD and CaO in the cement powder. The presence of calcium hydroxide a priori confers antimicrobial properties to this cement which were investigated in agar plates (diffusion method) against Streptococcus mutans, Lactobacillus acidophilus, Candida albicans, Enterococcus faecalis, Staphylococcus hominis (clinical isolates), and a preparation of polymicrobial flora isolated from dental plaque. The cement samples tested were prepared at molar calcium-to-phosphate ratios (Ca/P) of 1.67 to 2.75. A pure calcium hydroxide paste was used as reference material. Clear and reproducible bacterial growth inhibition was observed for cement samples with Ca/P > or = 2 against all the microorganisms tested. With Ca/P = 2.5, this cement alkalinizes dentinal tubules and provides a fluid-tight sealing that well compares with sealing obtained using a zinc oxide-eugenol cement without gutta-percha point. DCPD-CaO-based cement is therefore a potential root canal filler.
Laboratoire de Microbiologie, Faculté d'Odontologie, 545 Avenue du Professeur Jean Louis Viala, 34193 Montpellier Cedex 5, France.
Pierre
P
Michaïlesco
Michel
M
Kouassi
Hasna
H
El Briak
Anne
A
Armynot
Philippe
P
Boudeville
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D017610:Calcium Compounds; D002126:Calcium Hydroxide / Q000494:pharmacology; D002130:Calcium Phosphates; D003786:Dental Pulp Cavity / Q000601:surgery; D006801:Humans; D006878:Hydroxides; D010087:Oxides; D012387:Root Canal Filling Materials
D000900:Anti-Bacterial Agents; D017610:Calcium Compounds; D002130:Calcium Phosphates; D006878:Hydroxides; D010087:Oxides; D012387:Root Canal Filling Materials; C031356:hydroxide ion; C020243:calcium phosphate; C016538:lime; C494366:calcium phosphate, dibasic, dihydrate; D002126:Calcium Hydroxide