The topic of incomplete caries removal for the treatment of deep caries is one that has been discussed during several of my workshops lately, with most participants unaware of the procedure. Preserving pulpal vitality is a crucial step in reducing complications associated with caries, and there is mounting clinical evidence that one- or two-step incomplete (compared to complete) caries removal is a safe and effective treatment for deep caries that minimizes complications.   

incomplete caries removal benefits

The question of whether complete deep caries removal is necessary before the cavity is restored has been discussed as dentistry develops a better understanding of dental biofilm and the pathogenesis of caries.1,2,3,4  Multiple systematic reviews have been conducted in recent years to determine which procedures to remove caries result in maintenance of pulpal vitality and a reduction in complications and failure rates. Unfortunately, the systematic reviews I was able to find in a thorough search of the literature all reported a high degree of bias present in most of the studies reviewed, including unclear randomization, poor documentation, and sparse or contradictive information presented.1,2,3,4,5,  However, there was still compelling evidence for the recommendations made. 

The traditional techniques to remove deep carious lesions approaching the pulp is to remove all the soft demineralized dentin in one visit. The caries may also be totally removed using a two-step procedure, where the caries are removed in stages over two visits up to several months apart to allow pulp time to form reparative dentin, thereby reducing the risk of pulp exposure. 

Numerous clinical trials demonstrate the benefits of minimally-invasive versus complete caries removal, with partial removal in symptomless teeth significantly reducing the risk of pulpal exposure.1,4,5  In one- or two-step incomplete caries removal, some of the caries close to the pulp of the tooth are left in place. Unfortunately, there does not appear to be any research that indicates how much of the caries should be left in place in incomplete procedures. There is additional evidence that a single one-step incomplete evacuation reduces the risk of failure compared to two-step incomplete procedures.5 

The systematic reviews found there was no advantage to complete versus incomplete caries removal, with an overall reduced risk of pulpal complications and failures after incomplete compared to complete evacuation of the caries1,2,4,5.  Using one- or two-step partial caries removal showed success rates of over 95 percent up to three years and approximately 80 percent at five years, with partial caries removal likely more effective than step procedures at preserving tooth vitality.2 

In addition, treatments in younger patients (younger than 50 years) were more likely to result in sustained pulp vitality without radiolucency than those over 50.3  Failure rates were also influenced by the number of restored surfaces. The type of restoration used - for example, crowns and inlays - may reduce failure risk.5 

There are several current and recent studies evaluating the use of a doxycycline-containing resin-modified glass ionomer cement to inhibit cariogenic microorganisms, so this is another step to be considered when restoring the tooth. An adequate seal over the caries remaining in incomplete evacuations deprives the bacteria of its nutritional source, arresting caries development and allows for remineralization of carious dentin. 

Preliminary data shows a significant reduction of S. mutans without affecting the surface microhardness of the cement when doxycycline is present.6,7  Whether this translates into a reduction of caries reoccurrence under restorations long-term will require additional study. 

References

  1. Schwendicke F, Göstemeyer G. Understanding dentists’ management of deep carious lesions in permanent teeth: a systematic review and meta-analysis. Implementation Science : IS. (2016);11:142.
  2. Hoefler, Vaughan, Hiroko Nagaoka, and Craig S. Miller. "Long-term survival and vitality outcomes of permanent teeth following deep caries treatment with step-wise and partial-caries-removal: A Systematic Review." Journal of dentistry 54 (2016): 25-32.
  3. Bjorndal, Lars, et al. "Treatment of deep caries lesions in adults: randomized clinical trials comparing stepwise vs. direct complete excavation, and direct pulp capping vs. partial pulpotomy." European journal of oral sciences 118.3 (2010): 290-297.
  4. Ricketts, D. N., et al. "Complete or ultraconservative removal of decayed tissue in unfilled teeth." Cochrane Database Syst Rev 3 (2006): CD003808.
  5. Schwendicke, F., et al. "Failure of incompletely excavated teeth—a systematic review." Journal of dentistry 41.7 (2013): 569-580.
  6. Castilho, Aline Rogeria Freire de, et al. "Doxycycline-containing glass ionomer cement for arresting residual caries: an in vitro study and a pilot trial." Journal of Applied Oral Science 26 (2018).
  7. de Castilho, Aline RF, et al. "Mechanical and biological characterization of resin-modified glass-ionomer cement containing doxycycline hyclate." Archives of oral biology 57.2 (2012): 131-138.

(Click the link for more articles by Dr. Bob Winter.)  

Bob Winter, D.D.S., Spear Faculty and Contributing Author


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Comments

Commenter's Profile Image Andrew D.
August 28th, 2018
Well written and thank you for sharing/publishing - this needs to become standard of care. A couple of additions that would be nice would be photos and a description of materials that may be used. For example, are you using a pulp capping material when leaving affected dentin behind? Does cleaning the prep with CHX offer any added benefit (similar to the use of doxycycline) as a bacterial static agent? And finally, the most important part of leaving caries behind is making sure that your margins are caries free - correct?
Commenter's Profile Image Robert W.
September 5th, 2018
The research is not specific on the best method of treating the affected dentin left behind. Methods suggested include pulp capping with calcium hydroxide liner plus composite or using resin modified glass ionomer. Resin modified glass ionomer did result in less bacteria and microleakage when compared to composite. Bacteria can also be reduced by treating the area with chlorhexidine, bonding agents with antimicrobial properties such as Clearfil SE Protect, using antibiotics like doxycycline, or treating the area with high levels of ozone (one article specifically mentioned HealOzone by KaVo). As you note, the most important step is making sure your margins are caries free.