caoh

Question 1

Does CaOH2 Kill Bacteria

Answer 1

Yes 1. Siqueira – pH (12.5) alters enzyme activity disrupting cellular metabolism

a. Hydroxyl ions create free radicals – destroy cell membranes
b. Free radicals react with bacterial DNA, inhibition

2. Sjogren – 7 day CaOH eliminated most bacteria which survived instrumentation
3. Trope – CaOH inactivates LPS
4. Peters – CaOH limit but does not totally prevent re-growth of endodontic bacteria
5. Law 2004 – CaOH remains the best medicament available to reduce residual microflora beyond instrumentation effort.
6. Joyce 2004 – Heat 46C enhanced the antibacterial action of 0.12% CHX and 10% CaOH2 against E. Faecalis w/out increasing toxicity.
7. Mickel 2003 JOE – thin mix more effective antibacterial than thick mix

Question 2

Does CaOH dissolve tissue?

Answer 2

Maybe

1. Hasselgren, Cvek et al – CaOH completely dissolved porcine muscle tissue in 12 days. The addition of NaOCl after treatment with CaOH dissolved the tissue in as little as 60 minutes.
2. Morgan – CaOH solution was an ineffective solvent of pulpal tissue
3. Baumgarder – intracanal medication with CaOH or NaOCl for 1-7days to aid in dissolving tissue remnant was ineffective.
4. Turkun – Pretreatment with CaOH enhanced tissue dissolving efficacy of 0.5% NaOCl to the level achieved with 5% NaOCl. CaOH causes tissues to swell and become more accessible to the NaOCl.

Question 3

How do you place CaOH?

Answer 3

Krell – describes using the Messing gun to place CaOH

Sigurdsson – compared CaOH placement – Found the lentulo is better than injection (Calasept) which is better than placement with a K file.

Question 4

Does CaOH have an effect on the apical seal?

Answer 4

1. Porkaew – CaOH did not increase apical leakage
2. Wesselink – CaOH dressing does not effect the seal however study may be insignificant because CaOH decolorizes methylene blue (dye used)
3. Kim et al – CaOH groups showed significantly more dye leakage than the non-medicated control group.

Question 5

CaOH mixture

Answer 5

Hosoya 2001 – aqueous mixture gave optimum peak pH change after 14 days
Therefore use for 14 days, powder alone – peak pH change 49 days.

Pacios 2003 – CaOH2 aqueous solutions in CHX, propylene glycol, anesthetic, CMCP, CMCP-PG all maintained alkaline environment.

Question 6

Can CaOH be removed from the canal effectively?

Answer 6

YES

1. Margelos – Remove CaOH completely before using a ZOE sealer to avoid prolonged set time. EDTA is recommended for removal.
2. Baumgartner – Irrigants (H2O, NaOCl, EDTA) effectively removed CaOH dressing.

Question 7

Can CaOH diffuse through dentin?

Answer 7

1. Tronstad – pH is decreased during resorption. Teeth filled with CaOH have increased pH in the surrounding dentin. (7.4-11) The pH of cementum /PDL is not effected by CaOH in the canal. Increased dentinal pH may be the mechanism for stopping resorption.
2. Foster – CaOH diffuses through root dentin to exterior surface, removal of smear layer may facilitate this diffusion.
3. Nerwich – hydroxyl ions derived from a calcium hydroxide dressing diffuse through root dentin. 1-7 days elapse before pH began to rise in the outer root dentin, peaking at pH 9.3 apically after 2-3 weeks.

Question 8

Does CaOH weaken Dentin?

Answer 8

YES

Andreasen – limit use to a few weeks, strength was not reduced in study during period of 30 days

Cvek – longer term use in immature teeth weakens tooth structure.