There are several ways to treat caries, but the primary concern of most patients is cost, while practitioners are concerned more with effectiveness.
With that in mind, researchers from the Clinic for Conservative Dentistry and Periodontology at Christian-Albrechts-University and other German researchers set out to compare the cost-effectiveness of one- and two-step incomplete excavations and complete excavation over the long term (Journal of Dental Research, August 14, 2013). The researchers were clear in their opinion after the study's completion, which involved the use of Markov models.
"Based on the best available evidence, the present study found one-step incomplete excavation to be the most cost-effective strategy compared with two-step incomplete excavation and complete caries removal, retaining teeth and their vitality longer at lower costs," the researchers wrote.
A one-step approach with partial excavation of the carious dentin without exposing the pulp and sealing it would also be likely to, in the opinion of the researchers, benefit those with high treatment needs.
"The 'take-home-message' would most likely be that even such routine work like caries excavation has immense long-term ramifications, and that leaving some carious dentin close to the pulp may be most beneficial for both the patient and the paying party," explained Dr. Falk Schwendicke, an associate professor at the department of operative and preventive dentistry at Charité - Universitätsmedizin in an email to DrBicuspid.com.
Long-term risks
Previous research has built a case for incomplete caries removal. For the current study, the researchers compared the one-step approach to a two-step treatment with incomplete removal of carious biomass in the first and complete excavation in the second step. They also included complete caries removal.
"There is currently no indication why one-step excavation should not be the treatment of choice," Dr. Schwendicke noted. "However, we also support performing two-step excavation. In such treatment, it would be possible to control the inactivation and rehardening of carious dentin in the second step, and dentists could omit the second excavation, thus combining both: minimal-invasive caries treatment and some control and reassurance regarding the remaining carious dentin."
The researchers used Markov models to simulate treatment for a deep caries lesion in a 15-year-old patient's molar; in the two-step model, the second step where the second excavation and provision of the definitive restoration took place six months after the first.
Complications were selected based on the current evidence taken from a systematic review of the literature and the input of an expert panel.
In most caries lesions treatment studies, the researchers wrote, the maximum follow-up is typically two years, and "there is currently no indication that long-term risks differ for incompletely and completely excavated teeth." Consequently, they inferred that risk of failure was independent of the choice of initial excavation method after two years.
The researchers calculated weighted annual failure rates for each health state, for example, completely excavated teeth, one-step incompletely excavated teeth, root-canal-treated teeth, etc. Then they used different studies to calculate these rates; nine were used for excavation methods. The rate was estimated depending on the time a tooth spent in the state.
"We made conservative assumptions regarding costs and performed number of treatments," Dr. Schwendicke said. "Thus, we reflect cost awareness and limitations within public healthcare systems."
A simulation study
The research was performed in Germany, where there is a universal multipayor healthcare system, so the researchers' cost-effectiveness analysis was applied to a mixed public-private-payor perspective.
The analyses were based on 100 simulations, each with 100 random samples. "One-step incomplete excavation retained teeth and their vitality longer than two-step incomplete and complete excavations and dominated the other strategies in 70% to 100% of simulations," the researchers wrote.
"Pulpal exposure is usually treated by direct capping, which often fails, thus leading to root canal treatment," Dr. Schwendicke explained. "Avoiding this chain of retreatments seems to allow retaining teeth and their vitality for longer and to reduce costs."
One-step incomplete excavation was also the most cost-effective approach.
"Within the worst-case scenario, two-step incomplete excavation was found slightly less cost-effective than complete excavation," the researchers wrote.
Dr. Schwendicke acknowledged that the healthcare setting will affect the cost-effectiveness, but he feels the study findings can still be applied across most healthcare systems.
"Prices for certain treatments will widely differ, as will chosen treatment alternatives," he said. "Taking into account that all these prices and alternatives would not greatly differ between the three excavation methods, I assume that cost-effectiveness rankings should be similar in another setting."
While he and his colleagues expressed confidence in their conclusions, Dr. Schwendicke urged dental practitioners to take them with a grain of salt.
"It needs to be stressed that this is a simulation study (there is hardly any chance to analyze such lifelong sequence of events clinically)," he said, "and caution is necessary when interpreting the results."
