Dental Caries in Relation to Public Health 1

Dental Caries in Relation to Public Health 1

Dental Caries in Relation to Public Health

Heather Blair

MPH 500, Fundamentals of Public Health

Concordia University of Nebraska

October 18, 2013

Fall Semester

Dental Caries in Relation to Public Health

These days it is not uncommon to hear a colleague, friend, family member or child complain about having to go to the dentist to have a filling. For many people their six month routine preventative care (dental prophylaxis) visit, is not their only routine appointment. Many people, especially children have an oral disease – Dental Caries(Tinanoff, Kanellis,Vargas, 2002). Some research has indicated that most adults have had some dental caries by the time they reach their early 40’s (Geurink, 2005, p. 4). Dental caries affects 60 – 90% of children (Yokoyama et al., 2013). Dental caries is the most common, chronic, infectious, preventablemulti-factorial disease.

Risk Factors

Dental caries is a disease that is the product of a combination of variants coming together in the right ways to produce cariogenic activity. In laymen’s terms dental caries is the result of a susceptible host/tooth (person) + cariogenic bacteria (ex. Mutans Streptococcus) + dietary fermentable carbohydrate (sugar) which then form an acid and if not removed in a timelymannermay create a hole in a tooth (Darby, Walsh, 2003, p 239).

There are many risk factors that play an important role in this oral disease. Biologic variation accounts for the disease susceptibility among individuals, their heredity or genetic endowment ((Burt & Eklund, 2005). It is not uncommon to hear people say they were born with soft teeth or that they inherited mom or dad’s teeth, but what they are really saying is that they inherited the genetic predisposition for dental caries. The outer layer of the tooth is covered by enamel, which is the “hardest tissue of the body; its mineral content far exceeds the mineral content of …bone [by] (50%) (Melfi & Alley, 2000, p. 81). This indicates that rather than inheriting “soft teeth”, they inherited host susceptibility. Other factors that contribute to host susceptibility are alignment of teeth, congenital enamel or tooth defects (amelogenesis imperfecta, enamel hypoplasia, etc.), age, race, and gender. Additional risk factors include: Physical environment – exposure to fluoride through either oral supplements or community water fluoridation, Social environment – education level of the family, cultural beliefs, and the quality of their neighborhood, Lifestyle – using tobacco or exposure through 2nd hand smoke, physical activity level, dietary habits that may either include a well balanced diet or one that is has more exposure to fermentable carbohydrates, personal home care which may or may not include regular brushing and flossing, and dental appointment attendance (Burt & Eklund, 2005).

The bacteriathat are most associated with dental caries areMutans Streptococci and Streptococcus Sobrinus (Wilkins, 2005). The mouth is the perfect place for these bacteria to grow, multiply and become virulent strains, due to the warm, wet and dark environment. The position of the teeth can make it difficult to remove all the bacteria present during regular homecare. There is usually a constant source of food, when we eat the bacteria does as well. Frequency vs. quantity is important risk factor when discussing the introduction of fermentable carbohydrates. For instance someone may say, “I only drink one Coke a day.” But if they open it at 8:00 am when they get to their desk, constantly sip it all day finally finishing it at 5:00 pm when they leave for the day, they are bathing their teeth in that sugary acidic liquid and their teeth never get a break to bring the pH back to a neutral state.

Measuring Dental Caries

In order to determine what the true prevalence and impact of dental caries is there has to be a criteria for diagnostic measurement. For a study to have statistical significance it must be quantitative – measurable and qualitative – which answers the why, adding meaning to the data. The measurement most often used is the DMF indexand is the screening tool for the basic oral epidemiologic examination (Geurnik, 2005). The DMF index is an irreversible index -meaning that the teeth identified will not go into remissionwithout intervention (Geurnik, 2005). The DMF index is used to identify surfaces on permanent teeth. The DMF acronym stands for: D – decayed teeth, M – missing teeth and F – teeth that had been previously filled (Burt & Eklund, 2005). There is a similar index for primary teeth, the def index. The def acronym stands for: d – decayed teeth, e – teeth indicated for extraction and f – filled teeth(Burt & Eklund, 2005). These are universal measurement indexes that are the standard protocol in dental caries research. There can be some gray areas in the reliability of data due to variability of examiner reliability. As well as the potential to over estimate filled teeth due to a preventative restoration placement or cosmetic bonding. Also if teeth are congenitally missing they are still just counted as missing even though it is not from a dental disease.

Some other more specific dental caries evaluation techniques include: The dichotomous scale – this scale evaluates the depth of the carious lesion. It evaluates the full range of carious activity with scores ranging from 0 – sound tooth surface to D4 – pulpal involvement (Burt & Eklund, 2005), RCI – root caries index. These are carious lesions that are apical to the cemenoenamel junction of the coronal portion of a tooth (Burt & Eklund, 2005), and ECC – early childhood caries. This is descriptive of extensive carious activity in children under six years old. It has also been described as baby bottle tooth decay and nursing caries (Burt & Eklund, 2005). These are all examples of quantitative data.

Qualitative data is usually accomplished through personal interviews: reviewing medical histories, talking with the patient or caregivers, socioeconomic status, observations: white spot lesions, visible bacterial plaque, perceived risk by the dental professional, and understanding traditions (Tinanoff, Kanellis & Vargas, 2002). The American Dental Association has also given oral health care professionals a screening form that is to be used with a patient to determine their personal risk. The form is the Caries Risk Assessment Form, this form reviews with the patient contributing conditions, general health conditions and clinical conditions that help to determine the patients’ own risk for developing dental disease (ADA, 2011).

This illustrates some of the risk factors that are associated in the development of dental caries. It is important to remember that dental caries is a bacterial disease that is dependent on the combination of host susceptibility, cariogenic bacteria and fermentable carbohydrates without these all working together there will not be dental caries, unfortunately these three factors come together regularly creating a public health concern.

Biostatistics.

When the public begins to complain of the same ailment or health care professionals notice consistent symptoms among their patients, it may trigger those involved in tracking public health statistics to take notice. There are many fantastic public health programs that help many people in ways that they would otherwise not receive the help. Periodically it is necessary to evaluate the efficacy of the program to ensure that it is doing what it was intended to do while remaining financially stable. Schneider (2014) said it well, “Statistics are the vital signs of public health” (p. 126). When it comes time to evaluate the need for or evaluate the out come of a public health program accurate biostatistics are necessary.

Dental caries has been on the statistical radar for quite some time. According to Jarus (2012), dental caries were noted over 2100 years ago in a mummy from Egypt. Dental caries is a disease that has been present since dietary changes introduced more sugar and refined foods as a regular dietary staple (Burt & Eklund, 2005).

The Centers for Disease Control (CDC) collects and compiles data for the National Health and Nutritional Examination Survey which is nationally recognized as a statistical indicator for how the health of the United States (CDC, 2013). The data is collected through the use of physical examinations and personal interviews. The survey focuses on both adults and children.

Another type of survey was developed by the Association of State and Territorial Dental Directors (ASTDD). Their survey is the Basic Screening Survey. This survey measures dichotomous data through a simple examination in which the examiner answers simply yes or no. If the answer is yes, then the patient has dental caries present or an obvious history of dental caries. If the answer is no, then the patient does not have dental caries present or a previous history of dental caries. This survey uses the DMFS index for adults and the defs for children as the measure (Geurink, 2005).

In a paper by Dye, Li and Beltran-Aguilar (2012) reviewing the NHANES survey, they noted that 75% of people have had a history of dental decay that has been restored through the use of amalgam, composite, or crowns (p. 1). The survey also indicated that “one in five people have untreated dental caries” (p. 1). One of the significant findings from this survey was that untreated dental decay varied considerably between different socioeconomic groups (p. 2). Another area that was measured was the placement of dental sealants. A sealant is placed by a dental professional as a preventative measure to provide a barrier for cariogenic bacteria to not settle in the pits and fissures, making the teeth less susceptible to dental caries (Burt & Eklund, 2005). This survey indicated that 27% of children and adolescents 5-19 years old had at least one dental sealant present (Dye et al., 2012). This sounds pretty good until you break down the numbers. The three groups that were measured were Non-Hispanic white which had a 30.2% dental sealant placement, Non-Hispanic black which had a 17.3% dental sealant placement, and Mexican American which had 22.6% dental sealant placement (Dye et al., 2012, p. 3). It becomes more concerning to note that only 19.7% received dental sealants that were below 100% of the poverty level vs. 32.3% received dental sealants that were 200% of the poverty level or higher (Dye et al., 2012, p. 3). This is just one example of where the difference in socioeconomic level has an effect on treatment received.

In an article by Bloom, Simile, Adams & Cohen (2012), which was a review of the National Health Interview Survey (NHIS) . This article began with a reflection from the U.S. Surgeon General in a report that was issued “calling attention to the “silent epidemic” of dental and oral diseases suffered by millions of children and adults throughout the United States.” (p. 1). As more and more research has been conducted in recent years, there has been a correlation noted between oral health and overall health (CDC, 2013). This article highlighted some of the reasons that people do not visit a dentist – 42% could not afford treatment or did not have a dental insurance and fear was highlighted as another reason that 1 out of 10 did not go (Bloom et al., 2012).

Geurnik (2005) states, “Dental disease is a universal problem that does not undergo remission if left untreated. About 99% of adults have had tooth decay by the time they reach their early 40s” (p. 4). Through diligent data collection public health professionals are able to direct programs where the need is found to be the greatest. Once the program is established the regular monitoring of surveys allow for programs to be measured for their greatest efficacy for the populations that they are serving.

Biomedical Basis

Dental disease is all about the bacteria! There are billions of bacteria that are beneficial to humans. Although, we often hear about the bacteria that is disease causing (UXL Encyclopedia of Science, 2002). In fact, less than 1% of bacteria is associated with disease or illness that makes people sick (NIH, 2013). Bacteria helps us to produce needed vitamins, digest food, some even kill disease causing cells (NIH, 2013). Bacteria are single celled and one of the smallest living organisms (UXL, 2002). The NIH (2013), states [bacteria] “are so small that a line of 1,000 could fit across a pencil eraser.”With bacteria being present everywhere, it is not a surprise to find that it has been associated with oral disease and has a positive correlation with dental caries.

Interestingly, there was a Dutch scientist Antonie van Leeuwenhoek (10/24/1632 – 8/26/1723) that first discovered oral bacteria with only the use of a microscope (Encyclopedia Britannica, 2013). Hiyari & Bennett (2011), noted that some of his initial experiments included scraping the white material [bacterial dental plaque] lodged between his gums and teeth, which he then examined and observed the “moving animalcules”. This began the study of the bacteria with in the oral cavity.

Bacteria that is found in the mouth is part of the oral biofilm. Nield-Gehrig & Willmann, (2008), describe a biofilm as “a well-organized community of bacterial that (i) adheres to surfaces and (ii) is embedded in an extracellular slime layer.” Oral biofilms are well suited to the mouth which provides a constant source of moisture, a regular diet of nutrients, warmth, darkness and varied surfaces for attachment (Hiyari & Bennett, 2011). Oral biofilms are a complex and diverse composition of micro-organisms, which has made the studying of them difficult to culture individual bacteria separately (Do, Devine & Marsh, 2013). Hiyari & Bennett (2011) state that “many of the bacteria present in the oral cavity are viable but not culturable, which severely limits laboratory analysis.” Do et al. (2011) noted that “even when isolation of culturable organisms is achievable, one must be aware that a single species might behave differently under laboratory conditions than when it is in its natural habitat.”

Within the mouth the oral biofilms differ depending on the surface that it is attached to. Clean teeth are covered in a salivary glycoprotein film which is called the acquired pellicle (Hiyari & Bennett, 2011). The acquired pellicle is what the oral biofilm attaches to, through “weak, long-range physicochemical interactions between charged molecules…” (Do et al., 2013). The acquired pellicle attracts the attachment of gram positive primary colonizers, such as Streptococcus mutans, Streptococcus anguis, Streptococcus sobrinus and Lactobacillus (Hiyari & Bennett, 2011). These gram positive bacteria are the bacteria most associated with dental caries. Depending on the oral surface there may be more bacteria present than in other areas for instance – the oral mucosa has a high rate of desquamation as opposed to proximal surfaces of teeth (Do et al., 2013). About 90% of the carious lesions are found are in the pits and fissures of posterior teeth (Zero et al., 2009).

Zero et al. (2009), states “dental caries is a chronic, dietomicrobial, site specific disease caused by shifts from protective factors favoring tooth remineralization to destructive factors leading to demineralization.” These shifts in the protective factors are a result of the oral bacteria becoming acidogenic (Do et al., 2013). Remembering that dental caries is the result of a susceptible host/tooth + cariogenic bacteria + dietary fermentable carbohydrate which then form an acid and if not removed may dissolve tooth structure creating a dental caries (Darby & Walsh, 2003). The initial introduction of bacteria is during infancy, usually from the primary care giver when tasting food to check for temperature, cleaning of a pacifier with their own mouth, or kissing the infant (ADA, 2013).

In a study done by Loyloa-Rodriguez (2007), that concentrated on the Distribution of Streptococcus mutans and Streptococcus sobrinus in Saliva of Mexican Preschool Caries-free and Caries-active Children by Microbial and Molecular (PCR) Assays. The bacteria that was studied focused on Streptococcus mutans, which is often associated with pit and fissure caries and Streptococcus sobrinus, which is often associated with smooth surface caries. This study included 80 children with a primary dentition, 40 children with dental caries and 40 children that are caries free. The study surprisingly showed that there was not statistical difference between the two groups of children, caries active and caries free with Streptococcus mutans(p>0.05), but there was a presence of Streptococcus sobrinus that was isolated twice as much in the children with active caries 50% vs. 22.5% in the caries free children. This showed a statistical significance of (p<0.05). This study was the first of its kind to show a shift from Streptococcus mutans to Streptococcussobrinus, it will be interesting in the future to see if more studies have the same findings and if research begins to target the Streptococcussobrinus bacteria more. Studies have shown that there is a bacterial component that is critical for dental caries to occur. Regardless of which bacteria is the primary agent involved in cariogenic activity, it’s all about the bacteria!

Social & Behavioral Aspect of Dental Caries

It has been established that oral health is an important part of overall health. Some describe the mouth as the window to the rest of the body. Sometime ago the mouth was separated from the rest of the body with the advent of separate medical and dental insurance. When this happened people continued to have a special value placed on regular medical care, but dental care began to suffer, as many people lacked the dental insurance and value for oral health care. Today there are many oral health disparities seen for various reasons, most have a direct correlation to socioeconomic status.