The Effect of Long-term Dressing with Calcium Hydroxide on the Fracture Susceptibility of Teeth.
INTRODUCTION
Calcium hydroxide has been widely used to treat immature teeth to achieve periodontal healing and to promote the formation of an apical barrier. However, retrospective clinical studies have shown a high incidence of cervical root fractures with long-term calcium hydroxide dressing. The alkalinity of calcium hydroxide has been suggested to weaken the root. In vitro studies using ovine teeth show conflicting results on fracture strength of dentine, although different commercial products may have influenced the results. The purpose of this study was to investigate the effects of 2 commercial products used in prior studies (Calasept Plus and UltraCal XS), as well as a new product (Calmix) that uses a nonaqueous vehicle that allows for a higher pH, on the fracture strength of dentine over time.


METHODS
A total of 330 lamb incisor teeth were collected and the canals prepared so that 3 commercial calcium hydroxide products as well as a positive control of pure calcium hydroxide slurry that filled the root canal from the open apex and a negative control of saline was tested. The teeth were loaded until fracture with a universal testing machine at time points 0, 3, 6, and 9 months and the force to fracture was calculated. The data were analyzed with Friedman analysis of variance and Mann-Whitney t tests.


RESULTS
No statistical differences were observed between the different calcium hydroxide products and the negative controls.


CONCLUSIONS
Thin and fragile roots could be the cause of fracture rather than the calcium hydroxide dressing.
['Kahler|Sam L|SL|', 'Shetty|Sowmya|S|', 'Andreasen|Frances M|FM|', 'Kahler|Bill|B|']
D000818:Animals D001458:Bandages D002122:Calcium Chloride D002126:Calcium Hydroxide D003804:Dentin D004338:Drug Combinations D011189:Potassium Chloride D012756:Sheep D017693:Sodium Bicarbonate D012965:Sodium Chloride D013997:Time Factors D014082:Tooth Fractures
Calcium hydroxide immature teeth cervical root fractures fracture strength pH