Tooth wear is a normal physiological process which can affect aesthetics, function, and even cause pain. Additive dentistry helps to preserve the existing tooth structure, making it a healthier and superior treatment option to traditional reductive methods.
by Dr Christopher Ho
Not to be taken lightly
Additive dentistry can be used to solve patients’ complex dental problems while preserving their existing tooth structure, and more dentists should use it, says Dr Christopher Ho, a lecturer at the University of Sydney, Australia, visiting lecturer at King’s College London in Britain and faculty member of the Global Institute for Dental Education and Academy of Dental Excellence.
There in an increasing incidence of tooth wear – the loss of tooth substance by means other than decay or trauma. Tooth wear is a normal physiological process occurring throughout life, but it can often become a problem affecting function, aesthetics or cause pain. This loss of tooth structure or wear is often commonly termed abrasion, attrition, erosion and abfraction.
- Attrition – mechanical wear that occurs due to bruxism, the grinding or clenching of teeth that can occur during sleep or even awake.
- Abrasion - progressive loss of tooth substances caused by mechanical actions other than mastication or tooth-to tooth contact. Abrasion is commonly associated with incorrect toothbrushing technique or from brushing with excessive force. This may cause notching around the gum margin. It will also be seen in individuals who use their teeth as a tool (e.g., to remove bottle tops, to hold pins, clips or nails) or even from pipe smoking or tooth picks.
- Erosion - progressive loss of tooth substance by chemical or acid dissolution, and no bacteria are involved. Erosion of tooth surfaces is mostly the result of frequent consumption of carbonated drinks (including sparkling water) and fruit juices with high levels of acidity, however it can occur from intrinsic acids such as individuals who suffer from gastroesophageal reflux disease (GORD) or from certain eating disorders (e.g., anorexia, bulimia), or from patients with different syndromes and other medical issue
- Abfraction - an angular notch at the gumline caused by bending forces applied to the tooth, normally in conjunction with chemical dissolution
Often, wear is a complex combination of these and there is difficulty identifying a single aetiological factor. The decision to treat is often initiated by patients either from symptoms of sensitivity, chipping/fractures of teeth or alternatively may be cosmetically focused.
The main focus should be on identifying the aetiology of tooth wear and addressing this underlying issue prior to treatment to ensure that there is no further progression of tooth wear. This applies to patients that undergo no restorative treatment but just monitoring and review, and also to patients that may undertake a reconstruction of their mouths. If this is not addressed, the future restorations may suffer the same fate and fail prematurely for patients. Treatment will be ineffective in the long term unless the aetiological factors are eliminated.
The different treatment approaches have historically involved a reductive approach whereby one to two mm of tooth structure were removed from teeth for a full crown. This can be destructive of tooth surfaces, weakens the tooth, as well as cause nerves inside the teeth to become non-vital and require root canal treatment. With the advent of new adhesive technology, we are able to use additive techniques with either composite resin or ceramic to build up the teeth. Often in tooth wear, there is excessive destruction of the vertical heights of teeth, additive techniques can help in building up the teeth with either direct resin or usage of indirect ultrathin ceramic restorations offer a more conservative option as well not requiring the removal of significant tooth structures for crowns.
According to Young (2001), groups of patients at risk of developing excessive tooth wear include patients with anxiety, depression, anorexia or bulimia nervosa on medication, which results in the loss of salivary protection against both acid soft drinks and intrinsic acid vomiting. Healthy, active people are also at risk of tooth wear, whose sports or workplace dehydration reduces salivary protection of the teeth against acids in sports, soft drinks and caffeine. Diabetics and patients with other cardiovascular diseases also suffer from reduced salivary protection of the teeth because of their condition or from antihypertensive or diuretic medication.
“In the past, we had to grind teeth down to provide room for crowns made of porcelain fused to metal. Now, we can just bond very thin layers of materials such as ceramic or nano-hybrid composite resin to the remaining tooth structure instead. This is healthier and a superior treatment option because when you remove tooth structure, you are removing the integrity of the tooth and weakening the tooth, and you might also cause inadvertent damage to the pulp in the tooth,” Dr Ho explained.
Furthermore, such additive techniques help to preserve teeth’s remaining enamel. “When you bond materials to enamel, you get a very predictable bond over the long term, which is good for patients,” Dr Ho said. Recent advances in additive materials, such as the nano-hybrids and new versions of lithium disilicates, also have increased strength, excellent longevity and better aesthetics with lustre and fluorescence similar to natural teeth.
Dr Ho said that additive dentistry is especially recommended for people whose teeth has been worn down due to the grinding of teeth or acid erosion caused by poor diet or diseases such as anorexia and bulimia. Dentists should also be familiar with both direct and indirect additive restoration techniques and use them either singly or in combination depending on the patients’ needs.
He concluded, “All dentists should have these additive concepts in their back pocket and know when and how to use them.”
Young, W. G. The Oral Medicine of Tooth Wear [Review]. (2001). Australian Dental Journal, 46(4), 236-250.
Source: IDEM 2018