Regressive Alterations of Teeth

Introduction

Attrition, abrasion, and erosion are the three main regressive alterations of the teeth seen in the permanent dentition. Although tooth wear is a part of the normal aging process, it remains a major cause of concern to many patients. Most dental surveys carried out, especially amongst middle-aged and elderly individuals, show an increased tooth wear rate, mainly because of the two layers of the teeth that are the dentin and the superficial but strong enamel wearing out. This tooth wear is part of a group of regressive changes mainly due to non-bacterial causes (unlike dental caries, which have a bacterial origin).

The affected teeth by these alterations in tooth structure cause not only sensitivity but also an impairment of normal tooth function. Mechanical microfractures and loss of tooth structure in specific areas accumulate a stress load upon the remaining portion of the affected tooth (especially the masticatory or chewing forces that determine the tooth functionality). Regressive alteration is a condition that has a multifactorial origin dentally, causing the loss of the tooth layers, enamel, and dentin. Have a look into what are the causes, symptoms, and management of these regressive alterations.

What Are the Effects of Regressive Alterations?

The effects of regressive alterations are:

1. Irregular tooth surface leading to plaque retention and deposit accumulation.

2. Loss of masticatory efficiency or chewing and biting efficiency (as the stress load is unevenly distributed onto the tooth surface affected by alterations).

3. Pulpal exposure and weakened tooth structure, causing sensitivity and pain.

4. Compromised esthetics due to irregular appearance caused by alterations.

What Are the Regressive Alterations of the Teeth?

1) Attrition:

Derived from the Latin word attritium, which means the action of rubbing against something, and well-shaped wear facets can be seen on the functional surfaces of the teeth. This is predominantly a cause of esthetic concern in the upper and lower front incisors as it gives a cup-shaped edge to the incisal surfaces of the front teeth. As the dentin is less prone to any regressive alteration compared to the superficial enamel, these defects are visualized clearly. In addition, attrition on the proximal surfaces of the teeth leads to shortening of the dental arch.

Causes of Attrition:

• Abnormal bite or occlusion.

• Abnormal chewing habits.

• Developmental defects of teeth.

• Diet poor in nutrition.

• Opposing restorations that are uneven.

• Bruxism or night clenching.

Radiographic View:

• The crown of the tooth appears shortened, and the pulp chambers are sclerotic due to the deposition of secondary dentin.

• Hypercementosis, widening of the periodontal ligament space, and loss of alveolar bone surrounding the tooth can also occur.

2) Abrasion:

This condition is a pathologic wearing out of tooth enamel and dentin due to forces created by an abnormal mechanical process. Abrasion that is specifically caused by masticatory or chewing stress (by the friction of the food bolus) is termed masticatory abrasion, whereas the abrasion by aggressive or improperly aligned toothbrushing is termed toothbrush abrasion. In the case of toothbrush abrasion, studies indicate the friction is more; that is, the wear facets are seen on the left side in a right-handed person and vice versa because of the toothbrush holding hand’s alignment. The abrasion lesion presents as V-shaped notches on the cervical margins of the tooth surface.

Causes of Abrasion:

• Improper or forceful hard toothbrushing.

• Use of abrasive dentifrices.

• Biting hard objects like corks of bottles, pins, or fingernails.

• Improper use of toothpicks and dental floss.

Radiographic View:

• Appears as a radiolucent defect at the cervical margin of teeth.

• Partial or full sclerosis of the pulp chamber in case of toothbrush abrasions.

• Narrow semilunar groove appearance in the interproximal tooth surface in case of a toothpick or dental floss injuries.

3) Erosion:

It is a non-bacterial wear-out of a tooth substance by a chemical process. Erosion would be either extrinsic or intrinsic. The lesions found on the labial or buccal surfaces of ten teeth (front surface of the front and back teeth) have a smooth surface without any chalky appearance. If the lesion is palatal (surface of the tooth facing the palate), the teeth are decalcified (pyrolysis, which means the surface is eroded due to gastric regurgitation in the mouth).

Causes of Erosion:

The duration of exposure to the acidic environment by either diet or vomiting influences the extent of the abrasion on the tooth surface. The causes are,

• Intrinsic - Gastroesophageal reflux or vomiting (acidic pH of around 3.8 that causes pyrolysis on palatal tooth surfaces).

• Alcohol Abuse - Chronic regurgitation of fluid and vomitus cause erosion.

• Extrinsic - Frequent consumption of acidic beverages or carbonated beverages (soft drinks) is the common cause of abrasion, as observed by dentists. Also, frequent consumption of citrus fruits or chewable vitamin-C tablets, certain drugs like Amphetamine, ecstasy, and chewing of Aspirin tablets or powders are the other causes.

Radiographic View:

• Well-defined radiolucent defect with diffuse or clear margins on the tooth crown.

The other possible consequences of stress and pathology are abfraction and resorption.

4) Abfraction:

Wedge-shaped lesions are usually more occlusal (on the biting surface of the tooth) or cervical areas too because of mechanical stress. This occurs as a result of biting stress that can produce eccentric forces on the tooth surface. An abfraction lesion occurs at the area of greatest tensile stress application at or near the fulcrum of force.

5) Resorption:

This is a process in which tooth structure is progressively lost and damaged because of the resorbing cells called odontoclasts. It would be physiologic in the primary dentition in the children or pathologic in the permanent dentition in adults. Resorption mainly affects the maxillary incisors and the maxillary or mandibular (upper or lower) bicuspids or premolars.

How Does the Dentist Manage These Regressive Alterations?

When your dentist diagnoses these regressive tooth structure changes will mainly suggest procedures ranging from preventive night guards and splints to dietary modifications. However, when the lesions are moderate to large and require restorative fillings, then the dentist will prefer to fill the lesion with restorative glass ionomer cement or resin-based composites. Occlusal adjustments can be made either with or without restoration (based upon the extent and severity of the lesion and by increasing the vertical dimension at occlusion or VDO.

Conclusion

To conclude, though, the regressive alterations of teeth are not reversible once they occur; however, their progression can be prevented by the lesions treated timely by the dental surgeon. An orderly evaluation process and treatment protocol by the dentist is needed to restore the patient’s function and aesthetics correctly again.