by Patti DiGangi, RDH, BS
Breaking robotic behavior patterns
My first weeks out of hygiene school were very challenging with the schedule, the record keeping, the staff, and the dentist, and then Mrs. Coutre yelled at me. I didn’t mean to set her glasses down on the lenses. I was devastated. In the many years since then, I have not forgotten Mrs. Coutre’s lecture. I learned the basic lesson of handling eyeglasses properly, and now it has become routine for me.
Routine is helpful in our daily lives. Yet routine can become robotic where we follow an unchangeable habit based on past learning. As the relationship between the mouth and body becomes clearer, and with the advent of minimal intervention philosophies, today’s dental professionals must stretch beyond robotic routines and regularly reevaluate what we do. Let’s start with a very basic piece of most instrument packs - the explorer and periodontal probe. Are they the best diagnostic modalities in today’s world?
Moving to a biotherapeutic model
Our tradition has been to detect disease and repair the damage. Simply restoring teeth does not halt the disease process. By using different detection methods to identify early markers, we could intervene much sooner. The National Institute of Dental and Craniofacial Research (NIDCR) is pursuing a research agenda designed to find better diagnostics and therapeutics. In a 2004 guest editorial, Dr. Lawrence A. Tabak, director of the NIDCR, said, “Our collective goal is to move from the current surgical model of dental practice to a chemotherapeutic or biotherapeutic model. Instead of waiting for caries to become clinically obvious, we need tools that allow us to identify people at high risk and diagnose their disease very early. Instead of removing carious tooth substance, we need treatments that enable us to reverse early disease, such as remineralization agents for incipient caries. And instead of managing bone and connective tissue damage from periodontal infections, we need strategies for preventing the attachment and colonization of disease-causing bacteria in the first place.”1
These thoughts are not just for the future of the research community. Many early detection modalities and healing treatment therapies are already available, yet adoption has been slow. A majority of professionals are still picking and probing with the same instruments used for detection since the 1800s.
Explorers - time honored
In a 2005 point/counterpoint article on explorer use, Dr. James Hamilton, clinical associate professor in the Department of Cariology at the University of Michigan, said the reasons for continuing to use an explorer in clinical practice include:
- Clinicians are well trained in using explorers.
- Explorers are time efficient.
- Explorers have excellent sensitivity.
- Explorers are a time-honored part of dentists’ armamentarium.
He further stated that microscopic damage to the teeth can be attributed to explorers, but there are no studies to show this is consequential.2 These arguments come fully from the surgically/restoratively biased treatment philosophies. His words seems to say, “If it ain’t broke, don’t fix it,” and because we haven’t figured out a way to measure the harm, the damage doesn’t count.
Dr. George Stookey, distinguished professor emeritus at the Indiana University School of Dentistry Emerging Technologies Center, disagreed in the counterpoint portion of the article.3 These differing opinions are based on a philosophical stance or the paradigm through which each man sees. Dr. Hamilton’s views are based on a surgical/repair model, whereas Dr. Stookey believes this longstanding approach may no longer be the best.
Dental caries is initiated by specific bacteria - Streptococcus mutans and Lactobacillus - either separately or together, and modified by host and environmental factors. As a bacterial infection, caries is a process, not an endpoint.4 The presence of healthy saliva will provide buffers and extra calcium and phosphate to reverse the early damage caused by demineralization. Dr. Doug Young, associate professor in the Department of Diagnostic Sciences at the University of the Pacific School of Dentistry, said, “Caries management by risk assessment (CAMBRA), where risk factors are ‘rebalanced’ to that of health, is a sound strategy that is one step closer to ‘curative’ dentistry and improving the quality of life of dental patients.”5 Figure 1 diagrams Dr. Young’s important description. In 2000, J. Featherstone said that by the time dental clinicians see a white-spot lesion, the subsurface may have lost as much as 50 percent of its original mineral, yet it is often covered by an “apparently intact surface layer” formed by remineralization.4
In 2001, the National Institutes of Health Consensus Panel on the Diagnosis, Treatment, and Management of Dental Caries published findings based on a systematic review of the literature and expert opinion.6 One of the major findings the panel agreed on was that the use of sharp explorers to detect primary occlusal caries adds little diagnostic information and may be detrimental. Reversing the caries process requires intact enamel, and explorers can rupture the surface layer. Systematic reviews can help practitioners stay abreast of the literature by summarizing large bodies of evidence and helping to explain differences among studies on the same question. It appears that Dr. Hamilton may not be aware of this body of research.
Clinical practices change very slowly. During the 20th century, the term explorer catch became part of the caries diagnosis vocabulary. The term is based in the surgically/restoratively biased treatment philosophies that continue to have a hold on our profession. Dr. Hamilton’s comments clearly show this bias. Many concepts debated in cariology for the past 10 to 20 years are still seen as “new” or “radical” in clinical practice.
It is not time to throw the baby out with the bathwater. Explorers should not be removed from the basic pack, but it is time to question their use and add other modalities to our diagnostic mix. An explorer cannot evaluate saliva. Early remineralization may be damaged by an explorer. Hygienists should not continue to scratch away and push explorers into tooth surfaces.
Not just calculus
Something else we need to question is, what creates periodontal breakdown? Dr. Robert Compton, chief dental officer for Delta Dental Massachusetts, said, “Almost all dental benefits are based on procedures developed in the 1950s.”7 The calculus theory was the dominant hypothesis before 1960. The belief was that periodontal disease was caused by calculus, which acted as a mechanical irritant. The goal was glassy-smooth roots and removal of actual tooth structure. The terminology “scaling and root planing” (SRP) comes from this calculus era, and is still unfortunately pervasive in our dental lexicon. Its continued use seems to prove Dr. Compton’s words. Periodontal probing was certainly taught as part of the calculus theory, though not as often performed in clinical practice.
In the mid 1960s, Loe and other researchers demonstrated that gingivitis resulted without plaque control, and could be reversed when plaque control was completed. From this information emerged the nonspecific plaque theory that all plaque is the same. It was assumed the quantity - not the composition - made the difference.8 Probing wasn’t as important, and flossing and self-care were the heroes of this theory.
In the 1970s, Syed and Loesche postulated that only certain bacteria are pathogenic. With the belief that periodontal disease results from specific bacteria, research focused on identifying specific perio pathogens.9 A periodontal probe cannot identify pathogens.
The ecological plaque hypothesis, which has been in practice since the late 1980s, is described in a 2003 article by D.B. Marsh and comes closer to current thinking of the interrelationship between the mouth and body: “ ... This research resulted in a novel hypothesis (the ‘ecological plaque hypothesis’) to better describe the relationship between plaque bacteria and the host in health and disease. Implicit in this hypothesis is the concept that disease can be prevented not only by directly inhibiting the putative pathogens, but also by interfering with the environmental factors driving the selection and enrichment of these bacteria. Thus, a more holistic approach can be taken in disease control and management strategies.”10 A periodontal probe cannot recognize pathogens nor accurately detect inflammation.
Periodontal probing: a guesstimate
Again, we are not yet ready to throw the baby out with the bathwater. At present there are no reliable clinical indicators of periodontal disease activity. Probing can be an important part of a diagnostic regime, but aspects and interpretations of its use are flawed or given too much weight in our decisions. Probing can help a practitioner identify sites of historic breakdown. Probing is most effective at measuring change. Studies have shown traditional manual probing is more often a guesstimate than an accurate measurement. Reliability estimates have shown variance of as much as 2 mm or more, even between trained and calibrated practitioners.11
It has been further speculated that probing depths may vary depending on the time of day, the mood of the practitioner, expectations, and other factors. There are numerous confounding factors that make bleeding on probing an inaccurate method for evaluating inflammation.12-13 Probing depth measurements do not necessarily reflect the extent of periodontal destruction. Recording clinical attachment levels with respect to the cementoenamel junction may be a way to monitor disease progression, yet waiting for disease to manifest and become measurable is again from the old surgical/repair model. A periodontal probe cannot accurately detect pathogens or inflammation.
No more robotic behavior
An unknown philosopher who seemed to understand our profession well said, “Everything is new in dentistry for 10 to 20 years.” Numerous diagnostic modalities for early detection have been available for some time, with many more on the horizon. But adoption is very slow. Our challenge is to break out of the comfort of our routines.
In a 2006 article about creating a humanoid robot, routine behavior is defined as the habitual performance of an established procedure or task occurring in a reactive manner, sometimes without awareness, which requires far less focused attention than deliberate behavior.14 Robotic behavior and following an unchangeable routine does not make sense in our current world. Today’s professionals must stretch beyond our routines.
Mrs. Coutre taught me a good lesson long ago that became part of my routine, but today her lesson would have an addition. Infection control now dictates that Mrs. Coutre wear protective eyewear. Robotic, unquestioned use of explorers or periodontal probes - even if they are time-honored traditions - is also no longer suitable. We are in a different era.
1 Tabak L. Dental, oral, and craniofacial research: the view from the NIDCR. J Dent Res 2004; 83:196-197. Available at: http://jdr.iadrjournals.org/cgi/content/full/83/3/196. Accessed Jan. 28, 2007.
2 Hamilton J. Should a dental explorer be used to probe suspected carious lesions? Yes - an explorer is a time-tested tool for caries detection. J Am Dent Assoc Nov. 2005; 136(11):1526-1532. Available at: http://jada.ada.org/cgi/content/full/136/11/1526. Accessed Jan. 28, 2007.
3 Stookey G. Should a dental explorer be used to probe suspected carious lesions? No - use of an explorer can lead to a misdiagnosis and disrupt remineralization. J Am Dent Assoc Nov. 2005; 136(11):1526-1532. Available at: http://jada.ada.org/cgi/content/full/136/11/1526. Accessed Jan. 28, 2007.
4 Featherstone J. The science and practice of caries prevention. J Am Dent Assoc July 2000; 131(7):887-899. Available at: http://jada.ada.org/cgi/content/full/131/7/887. Accessed Jan. 13, 2007.
5 Young D, Buchanan P, Lubman R, Budenz A. CAMBRA is minimally invasive dentistry. Dental Products Report May 2006. Available at: http://www.dentalproducts.net/xml/display.asp?file=3369&bhcp=1. Accessed Jan. 31, 2007.
6 Diagnosis and Management of Dental Caries Throughout Life. National Institutes of Health Consensus Development Conference, March 26-28, 2001. Available at: http://consensus.nih.gov/2001/2001DentalCaries115html.htm. Accessed Jan, 28, 2007.
7 Delta Dental of Mass. now covers dental implants. Delta Dental News Nov. 15, 2005. Available at: http://www.deltamass.com/news/article.asp?id=73. Accessed March 1, 2006.
8 Theilade E. The experimental gingivitis studies: The microbiological perspective. J Dent Res July 1996; 75(7):1434-1438. Available at: http://jdr.iadrjournals.org/cgi/reprint/75/7/1434.pdf. Accessed Feb. 2, 2007.
9 Syed S, Loesche W. Bacteriology of human experimental gingivitis: effect of plaque age. American Society for Microbiology. Infect Immun Sept. 1978; 21(3):821-829. Available at: http://iai.asm.org/cgi/reprint/21/3/821.pdf. Accessed Feb. 5, 2007.
10 Marsch PD. Are dental diseases examples of ecological catastrophes? Microbiology 2003; 149:279-294. DOI 10.1099/mic.0.26082-0. Available at: http://mic.sgmjournals.org/cgi/content/abstract/149/2/279. Accessed Feb. 6, 2007.
11 Araujo M, Hovery K, Benedek J, et al. Reproducibility of probing depth measurements using a constant-force electronic probe: analysis of inter- and intraexaminer Variability. J Periodontol Dec. 2003; 74(12):1736-40. Available at: http://www.floridaprobe.com/pubs/Reliability%20_Araujo%202003.pdf. Accessed Jan. 29, 2007.
12 Royzman D, Recio L, Badovinac RL, et al. The effect of aspirin intake on bleeding on probing in patients with gingivitis. J Periodontol May 2004; 75(5):679-684. Available at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15212350&dopt=Citation. Accessed Feb. 6, 2007.
13 Shimazaki Y, Saito T, Kiyohara Y, et al. The influence of current and former smoking on gingival bleeding: the Hisayama study. J Periodontol Aug. 2006; 77(8):1430-1435. Available at: http://www.joponline.org/doi/abs/10.1902/jop.2006.050422. Accessed Feb. 6, 2007.
14 Chernova S, Arkin R. From deliberative to routine behaviors: a cognitively-inspired action selection mechanism for routine behavior capture. Nov. 6, 2006. Carnegie Mellon Computer Science Department. Available at: http://www.cc.gatech.edu/ai/robot-lab/online-publications/ChernovaArkin_final.pdf. Accessed Feb. 6, 2007.
Patti DiGangi, RDH, BS, is a speaker, author, practicing dental hygiene clinician, and American Red Cross authorized provider of CPR and first aid training. She can be contacted through her Web site at www.pdigangi.com.