Periodontal disease (PD) and risk of diseases

Periodontal disease, also known as periodontitis, is a chronic bacterial infection of the gums and teeth.

Tooth brushing

According to a Cochrane review of 42 trials involving 3855 participants, compared to manual toothbrushes, powered toothbrushes with a rotation oscillation action provides better protection against gum inflammation (gingivitis) and plaque removal.²⁰

Chewing gum

Mastic or chewing gum can play an important role in prevention of caries. The benefits of chewing gum are based on its ability to stimulate salivary flow which helps promote food clearance from the mouth and reduce bacterial growth in saliva, such as Streptococcus mutans, and consequent plaque formation on teeth.^{21, 22} A study found the total number of bacterial colonies was significantly reduced during the 4 hours of chewing mastic gum compared to the placebo gum and significantly reduced plaque index and gingival index compared to the placebo group.²³

Chewing gums containing sugar substitute products such as xylitol are very effective for preventing dental caries by stimulating the salivary flow, although an antimicrobial effect cannot be excluded. Xylitol appears to be superior to the other sugar alcohols such as sorbitol, mannitol, maltitol, lactitol and the products Lycasin and Palatinit for caries control. Xylitol is a polyol sugar alcohol and is naturally sourced from plums, strawberries, raspberries and rowan berries. A number of trials suggest xylitol is more effective than those sweetened with sorbitol for reduction of caries^{24, 25, 26} however, another review of all clinical trials concluded that chewing sugar-free gum 3 or more times daily for prolonged periods of time may reduce caries incidence irrespective of the type of sugar alcohol used. ²⁷ Xylitol is not fermented by bacteria and causes a fall in plaque pH by having an inhibitory effect on mutans streptococci.

One study found a significant statistical reduction in the number of bacteria mutans streptococci found in saliva and plaque with a chewing program using xylitol-only chewing gums compared with xylitol-sorbitol chewing gum or control in 8-year old children over a 39-month period.²⁸ Another study suggested a different mechanism for xylitol chewing gum benefit in preventing caries in children.²⁹ This study demonstrated 5 grams of xylitol-containing chewing gums in children over a 14-day period reduced the glucose-initiated lactic acid formation in supragingival plaque by up to 22% compared with baseline and the control group. The authors concluded reducing lactic acid formation may play a more important role in reducing plaque formation, as the numbers of salivary mutans streptococci were unaffected in this study.²⁹

Halitosis

Sunlight

Sunshine is the main source of vitamin D produced by the body in response to direct skin exposure to ultraviolet B (UVB). Consequently, nil or minimal exposure to sun can contribute to vitamin D deficiency as seen in many community groups with dress codes (e.g. wearing veils), those living in geographically prone areas, especially over winter (southern or northern latitudes), those working indoors (e.g. office work), institutionalisation, prolonged hospitalisation and the bed-bound (e.g. stroke, elderly), and particularly in dark-skinned people who need longer sun exposure.^{38, 39} Vitamin D plays an important role in dental health (see the section on vitamin D below).

Mercury exposure

Dental amalgam is the most commonly used material in restorative dentistry. Dental amalgam is an alloy of silver, tin, copper and mercury.⁴⁰ Mercury vapour absorption through the lungs (by dental practitioners or patients) or accidental oral ingestion of mercury from cracked teeth containing amalgams (by patients) are the main sources of mercury exposure in dentistry. The safety of mercury exposure from amalgam fillings has been explored in Australia.⁴¹ The findings of the National Health and Medical Research Council (NHMRC) working party concluded there was a lack of evidence to confirm dangers associated with mercury toxicity from amalgams and no studies exploring health outcomes amongst dental patients with and without amalgams and neurotoxicity. Based on current evidence, the NHMRC working party also concluded there is no role for removal protocols and concomitant therapeutic regimens, such as chelation therapy, for patients attributing symptoms to mercury from dental amalgam restorations. The NHMRC working party claim that the release of mercury is at a slow rate from dental amalgams, generally of a few micrograms per person per day among adults dependent upon variables such as number and shape of fillings, eating habits, and bruxism. For the current mean numbers of amalgam fillings in Australian children and adults (0.5 and 8, respectively), daily mercury absorption per person is about 0.3μg and 3.5μg, respectively, which is tenfold and twofold (respectively) higher than dietary sources of mercury retained in the body.¹⁹

However, there have since been more studies exploring effects of amalgam in children. A study of 507 children (aged 8–10 years) with at least 1 carious lesion on a permanent tooth and no previous exposure to amalgam were randomised to receive routine dental care during the 7-year trial period, 1 group receiving amalgam restorations (n = 253) and the other group receiving resin composite restorations (n = 254). Baseline mean creatinine-adjusted urinary mercury levels were 1.0–1.5mg/g higher in the amalgam group than in the composite group (P<0.001) at the 7-year follow-up. This study found no significant differences in measures of memory, attention, visuomotor function or nerve-conduction velocities for the groups over the 7 years of follow-up.⁴²

A recent RCT of 534 children (aged 6–10 years) involving 5 community health settings compared neuropsychological and renal function of children whose dental caries were restored using amalgam or mercury-free materials.⁴³ Children with no prior amalgam restorations and ≥2 posterior teeth with caries were randomised to receive dental restoration during a 5-year follow-up period using either amalgam or resin composite (non-amalgam) materials. The researchers found higher mean urinary mercury levels in children with amalgams at 5- and 7-year follow-up respectively but no significant differences in IQ, memory, attention/concentration and motor and visuomotor performance in either group.

Cadmium (Cd) exposure

Smoking

Cigarette smoking, cigar and pipe use in smokers significantly increases the risk of developing a range of dental health problems, including increased risk of caries, gingivitis, tooth loss, ulcer formation, oral cancers and PD.⁵⁵ In general, smokers are 4–20 times more likely to develop periodontitis compared with persons who never smoked and, amongst current smokers, 74.8% of their periodontitis was attributable to smoking.^{56, 57} Smoking is a major preventable risk factor for PD and chronic destructive PD.

Smoking can adversely affect dental health by various mechanisms, such as defects in neutrophil function and host defences from nicotine leading to bacterial invasion and plaque formation, impairment of inflammatory and immune responses, increased alveolar bone loss, pocket formation and attachment loss, including adverse local and systemic effects (e.g. heart and lung disease).^{58, 59} Smoking also reduces wound healing following local trauma and dental treatment.

Smokers are also exposed to various chemicals and heavy metals, such as cadmium and lead from cigarette smoking, which are associated with PD and may aggravate existing renal impairment.⁶⁰

Smoking cessation can significantly reduce the risk of PD and increase the likelihood of tooth retention but it may take decades for this to happen.⁶¹

Dental anxiety

Dental anxiety is a common problem. High dental anxiety can be overwhelming for an individual and is strongly associated with poor oral health, particularly due to treatment avoidance. Studies of 272 adult private dental practice patients were assessed for anxiety, frequency of oral health care visits in the last 10 years and their preferred method to alleviate anxiety.⁶⁵

Twenty-six participants (9.56%) scored high in dental anxiety. The study demonstrated that high anxiety was associated with infrequent oral health care visits and dental patients employ numerous strategies for reducing anxiety. They concluded that oral health care practitioners need to be aware of the patient’s preferred technique for coping with anxiety and encourage them to use self-help techniques.

Mind–body techniques such as cognitive behaviour therapy (CBT), self-help techniques, relaxation and music therapy and exercise can be useful and effective for the management of panic and fear [see Chapter 4, anxiety].^{66, 67, 68} Many of these techniques can also help address psychological symptoms associated with dental anxiety and fear.

Psychological interventions — general

A Cochrane systematic review identified 4 studies that assessed psychological interventions aimed at increasing compliance of oral hygiene in adult patients with PD.⁶⁹

A total of 344 patients participated. Overall, whilst the quality of the studies were poor, there was evidence that psychological approaches improved self-efficacy beliefs in relation to flossing and improved behaviour patterns for oral hygiene related behaviours.

Brief relaxation and music distraction

A prospective RCT compared a brief relaxation method with music distraction and a control group.⁷⁰ Ninety patients with dental anxiety were randomised to either of the 3 groups. Both brief relaxation and music distraction reduced dental anxiety significantly. Brief relaxation was significantly superior to music distraction over the control group. Patients in the control group demonstrated no significant change in anxiety level.

The authors concluded brief relaxation was safe, economically sound and effective as a non-pharmacological approach to managing dental anxiety.

A trial of 44 adult subjects requiring surgery for root canal treatment procedure were randomised to a music group, which listened to selected sedative music using headphones throughout the root canal treatment procedure, or a control group where subjects wore headphones but without the music.⁷¹ Heart rate, blood pressure and finger temperature were measured before the study and every 10 minutes until the end of the root canal treatment procedure. The level of anxiety experienced by the patient was measured before the study and at the end of the treatment procedure. The results revealed that there were no significant differences between the 2 groups for baseline data and procedure-related characteristics, except for gender. The music group showed a significant increase in finger temperature and a reduction in anxiety score over time compared with the control group. The authors concluded the findings:

Virtual image audio-visual eyeglass system

Virtual image, audio-visual (AV) eyeglasses may play a role in dental anxiety and pain. In a study of 27 patients, the participants completed a Dental Fear Survey and the Fear of Pain Questionnaire-III before dental treatment.⁷² They were randomised to either watch and listen to a standard video using AV eyeglasses or not (control group). The AV eyeglass group demonstrated rescued anxiety and discomfort compared with control group. Patients showed a preference to use AV equipment compared to the traditional approach of no glasses and there was a significant reduction in treatment time in the first half of the dental procedure. Clinicians experienced no significant technical interference with their dental work by using the AV eyeglasses. The authors concluded AV virtual image eyeglasses may be beneficial in the reduction of fear, pain and procedure time for most dental patients.⁷²

Hypnosis and dental anxiety

Pre-existing anxiety and cognitions about dental procedures can predict dental anxiety. Hypnosis may be helpful for some patients, but not all. A study found that patient characteristics such as hypnotisability, trait anxiety and negative cognitions can predict which people develop dental anxiety and who will be more responsive to hypnosis.⁷³ Rapid hypnotic induction techniques by oral health practitioners (dentists or dental nurses) can be useful for treating anxious patients prior to procedures.⁷⁴ Children may be more receptive to hypnosis. A double-blind, control trial of 29 children (ages 4–13) were randomised to both hypnosis group and a no hypnosis group before a local anaesthetic injection for a dental procedure.⁷⁵ Each subject was evaluated during utilisation of hypnosis before injection, and once without. Subjects were videotaped during the procedure and behaviour rated independently by 2 paediatric dentists, using the North Carolina Behaviour Rating Scale (NBRS). They found hypnosis significantly reduced pulse rate and crying, especially in the 4–6 year-old children.

Behavioural therapy for dental fear

Behaviour therapy may offer more benefit in reducing dental fear compared with hypnosis. In a study with 22 women (mean age of 31.8 years) who suffered dental fear and avoided dental care (median time of 9.5 years), participated in a clinical study and were randomly assigned to 1 of 2 groups; hypnotherapy (HT) versus behavioural treatment based on psychophysiological principles (PP).⁷⁶ Both therapies involved 8 sessions followed by standardised conventional dental test treatments. Pre- and post-treatment measures were dental fear, general fear, mood, and patient behaviour. PP group statistically significantly reduced dental fear and improved mood during dental situations compared with HT group. General fear levels insignificantly reduced. Overall 11 of the 22 patients completed the conventional dental treatment without complications, indicating that they were more relaxed during the treatment.

Dairy intake — calcium and vitamin D

Low dietary calcium intake is associated with reduced bone mass and increased risk of osteoporosis. Best sources of calcium foods include dairy products (milk, yoghurts and cheese), fish (sardines with bones), green leafy vegetables and fruits. The recommended dietary allowance for calcium is 800mg/day.⁸³ Vitamin D deficiency is associated with rickets in children, osteoporosis; osteomalacia (reduced mineralisation of bone) and is common in the elderly and dark skinned people. The best source of vitamin D is from sun exposure. (Refer to Chapter 30 on osteoporosis for more information on calcium and vitamin D.)

Early childhood caries (ECC)

ECC is preventable and affects very young children, especially those from low-income families and certain racial and ethnic minorities. Dental caries are due to a combination of factors, including colonisation of teeth with cariogenic bacteria, food types, frequency of exposure of these foods to the cariogenic bacteria, duration of breastfeeding, fluoride content in fluids and susceptible teeth, especially in very young children.

Data from the Third National Health and Nutrition Examination Survey (NHANES III) of 2- to 5-year-old children, found those consuming best dietary practices (uppermost tertile of the Healthy Eating Index [HEI]) were 44% less likely to exhibit severe ECC compared with children with the worst dietary practices (lowest tertile of the HEI).⁸⁴

Sugars

Dental caries are more prevalent if sugars are consumed more frequently, particularly if retained in the mouth for long periods of time.⁸⁵ Sucrose forms glucan in the mouth that facilitates firm bacterial adhesion to teeth and limits diffusion of acid and buffers in the plaque.

Children should be encouraged to eat healthy snacks and foods, and discouraged from sugars and frequent consumption of juice, sugary drinks, snacks and sugary foods e.g. lollies, chocolates, toffees, lollipops. Children should be encouraged to brush their teeth immediately if consuming these foods.

Acidic diet and caries

It is well recognised that an acidic diet promotes caries. A study of 309 children’s diets found that large consumption of high-acidic beverages (e.g. fruit juices), vinegar, fruit, vitamin C supplements with low consumption of water and milk is associated with increased risk in caries and erosion.⁸⁷ A recent Australian study investigated the erosive potential of beverages in schools.⁸⁸ This study found that the majority of the tested beverages sold from school canteens exhibited erosive potential.

Table 28.1 lists the acidity of common drinks. A pH less than 5.0 should generally be reduced or avoided. Water and milk are preferred drinks to maintain good oral health.

Table 28.1 Acidity of common drinks

Vitamins

Vitamin D

Vitamin D has a pivotal role in bone metabolism, it controls intestinal calcium absorption plus its deposition into bone.⁸⁹ The main source of vitamin D is sunlight exposure (see Figure 28.1). Ninety percent of vitamin D is produced in the skin from sunshine exposure (UVB) with only 10% from dietary sources. Dietary sources include fatty fish (e.g. mackerel), cod liver oil, sun-exposed mushrooms and liver. The majority of women with osteoporosis have vitamin D deficiency and resulting bone loss.⁹⁰ The Geelong Vitamin D Study on postmenopausal women found that the majority of the participants were vitamin D deficient during winter.⁹¹

Figure 28.1 Major sources of sunlight

(Source: adapted from Nowson CA, Diamond TH, Psco JA, et. al. Australian Family Physician. 2004;33(3):133–8)

Vitamin D deficiency is likely to be the commonest nutritional deficiency in many countries, and may well be the most important one.^92–97 Risk factors for vitamin D deficiency include dark skin colour, dress codes (e.g. wearing veils), migrants, infants of migrant families, living in geographical prone areas, especially over winter (southern or northern latitude), institutionalisation, bed-bound, intellectual disability, prolonged and exclusive breastfeeding, restricted sun exposure, and certain medical conditions. Vitamin D deficiency has re-emerged as a public health issue particularly affecting infants and young children, potentially causing hypocalcemia, seizures, rickets, limb pain, tooth loss and poor dentition and risk of fracture.^98–104 Breastfed infants of mothers who were vitamin D deficient during pregnancy were at high risk of vitamin D deficiency.¹⁰⁵

A position statement released recently by the Australian and New Zealand Bone and Mineral Society and Osteoporosis Australia and the Endocrine Society of Australia is summarised in Figure 28.2.¹⁰⁶

Figure 28.2 Position statement: calcium and bone health

(Source: Australian and New Zealand Bone and Mineral Society and Osteoporosis Australia and the Endocrine Society of Australia, 2009)¹⁰⁶

Improved bone mineral density (BMD)

A large RCT of elderly people over a 5-year period demonstrated vitamin D combined with calcium supplementation has long-term benefit on BMD compared with calcium alone or control group, particularly in subjects with sub-optimal vitamin D levels.¹⁰⁷ Moreover, it is well documented that throughout the lifecycle the skeleton requires optimum development and maintenance of its integrity to prevent fracture. The data is promising for the use of combined calcium with vitamin D and the use of vitamin K.¹⁰⁸

Periodontal disease (PD)

Numerous articles indicate vitamin D and calcium deficiency are associated with bone loss and increased inflammation, which are well recognised symptoms of PD. Whilst studies suggest calcium and vitamin D may benefit periodontal health and calcium deficiency may be a risk factor for periodontal disease, there are no RCTs done to date to test this hypothesis.¹⁰⁹

Vitamin D and calcium enhances tooth retention

A placebo-controlled trial of 145 healthy subjects aged over 65 years were randomised over a 3-year period to calcium or vitamin D supplementation to assess bone loss from the hip. Furthermore, participants were further followed up for 2-years after discontinuation of study supplements and teeth were counted at 18 months and 5 years.¹¹⁰ During the trial, subjects were less likely to lose 1 or more teeth (13%) whilst taking calcium and vitamin D supplements compared with a larger proportion of subjects (27%) whilst taking placebo. At the 2-year follow-up period, of those with total calcium intake >1000mg/day, 31 of 77 subjects (40%) lost 1 or more teeth compared with a larger proportion of 40 of 68 subjects (59%) who consumed less calcium.

Recommended dosage is calcium citrate 800mg/day or calcium carbonate 1000mg/day.