In vitro study of the indirect action of calcium hydroxide on the anaerobic flora of the root canal

Abstract

The aim of this study was to evaluate in vitro a possible mechanism involved in the antimicrobial action of calcium hydroxide, namely absorption of carbon dioxide from the root canal. Twenty obligate and 20 facultative anaerobic bacteria isolated from infected root canals and identified to species level were used. For each bacterial species a standard concentration was achieved and 0.1 ml of the inoculum was spread on blood agar plates, which were consecutively incubated in an anaerobic chamber for 5-7 days. One experimental and one control group were studied: the experimental group included one plate with the bacterial species as well as one open plate containing 32 g calcium hydroxide paste at a mixing ratio of 6:4. Both plates were incubated in an anaerobic chamber for 72 h. The control group included only one plate containing the same bacterial species and was incubated under the same conditions. After a 72-h incubation, the number of the recovered bacteria were counted in both groups. Statistical analysis showed that the number of bacteria recovered from the control group was significantly lower than that of the experimental group, but no particular resistance of any bacterial species to calcium hydroxide could be detected. This finding strongly suggests that the ability of calcium hydroxide to absorb carbon dioxide may contribute to its antibacterial activity.

Antimicrobial effect of phytic acid on Enterococcus faecalis

“…At low concentrations, chlorhexidine has bacteriostatic effect due to the leakage out of small molecular weight substances. At higher concentrations, CHX precipitate and/or coagulate the cytoplasm which results in bactericidal effect [35]. In this study, 2% CHX showed high antibacterial activity in disk diffusion test with 30 mm zone of inhibition, but it was excluded from MIC experiment due to instant precipitation and turbidity that occurred after CHX and Mueller Hinton were mixed [36].…”

Current Trends in Use of Intracanal Medications in Dental Care Facilities: Questionnaire-based Survey on Training Dental Hygienists at Educational Institutions

“…Recently, its use as an intracanal medication has increased 9,16,[19][20][21] . In addition, calcium hydrox ide is suggested to be useful for destroying anaerobic bacteria, which are frequently detected in highlyinfected root canals 13) . Taken together, the use of formaldehyde preparations as intracanal medications has decreased, while the use of calcium hydrox ide for the same purpose has increased in Europe and the US.…”

The effect of calcium hydroxide on post-treatment pain

“…수산화 칼슘은 세균의 lipopolysaccharide를 분해하고 7,8) , 세균의 기질이 될 수 있는 괴사 조직의 잔사를 용해시킬 수 있기 때 문에 살균 효과를 나타낸다 9,10) . 또한, 수산화칼슘으로 근관 을 밀폐시키면 조직 삼출액의 유입을 효과적으로 차단하여 세균의 영양분이 공급되는 것을 감소시키며 11) , 세균의 생존 에 필요한 근관내의 이산화탄소를 흡수하기 때문에 부가적 인 살균 효과를 나타낸다 12) . 그리고, 치근단 조직내로 수산 화칼슘이 정출되면서 대식세포의 물질부착 능력을 감소시 켜 염증반응을 감소시킬 수 있다 13) .…”