A Clinical and Microbiological Study of Deep Carious Lesions during Stepwise Excavation Using Long Treatment Intervals.

Author(s): Bjorndal L, Larsen T, Thylstrup A.
Journal: Caries Res
Volume (number): Volume 31: 411-7
Month, Year: 1997
Major topic: Bacterial status of deep carious lesions after stepwise excavation
Minor topic(s): none
Type of Article: Research Study.
Purpose: This study evaluates stepwise excavation of deep carious lesions in terms of clinical and microbiological parameters. More specifically the study examines changes in bacterial flora before and after final excavation and determines if there is a relationship between bacteria and dentin characteristics.
Methods: 31 teeth with deep caries were included with 18 having decay covering over 1/3rd of the crown and 13 with decay covering less than or equal to 1/3rd of crown. All pulps tested vital and no teeth had a history of spontaneous or provoked pain. Treatment consisted of a first step of removal of central caries and superficial removal of the necrotic and demineralized dentin and complete removal of surrounding demineralized dentin. After two separate intervals of time, either 6-9 months or 9-12 months, the temporary restorations were removed and samples were taken. The clinical data evaluated color of dentin, consistency, and moisture at first excavation, after removal of the temporary restoration, and after final excavation. Microbiological data was obtained from the peripheral excavated hard dentin, the central demineralized dentin before final excavation, and after final excavation.
Findings: General characteristics of the dentin include the following: Dentin classified as very soft or soft was always wet after first excavation and that after the treatment interval, the dentin became dry prior to final excavation. The dentin became darker, harder, and drier after the treatment time. Also in general, cases which had light yellow color after final excavation had no bacterial growth while 7 of 8 dentin samples with light brown color and 2 of 4 with dark brown color had bacterial growth. Black staining in 1 tooth had the highest bacterial counts. Overall, there was a significant reduction (104 ) in bacterial counts (CFU’s) during the interval of temporary restoration. This initial step in stepwise excavation had a major impact in decreasing the bacteria in the tooth. In previous studies aggressive caries removal which may lead to a pulp exposure is not necessary, only removal of the central carious biomass, superficial parts of demineralized dentin and complete excavation of peripheral dentin is necessary
Conclusion: Stepwise excavation of deep carious lesions is an appropriate treatment for teeth with deep caries. The study also showed the relevance for microbiological studies in determining if bacteria survive in clinically excavated lesions.
Assessment of Article: Good scientific article demonstrating that it is acceptable to leave caries in teeth that do not exhibit signs and symptoms of pulpitis because the bacteria will diminish in a well sealed restoration.