Non-Carious Lesions and Their Management.pptx

NON-CARIOUS LESIONS AND THEIR MANAGEMENT  This LECTURE will present the various non-carious causes of tooth loss and their management strategies. EROSION Definition. Erosion is the wear or loss of tooth surface by chemical action in the continued presence of demineralizing agents with...

NON-CARIOUS LESIONS AND THEIR MANAGEMENT  This LECTURE will present the various non-carious causes of tooth loss and their management strategies. EROSION Definition. Erosion is the wear or loss of tooth surface by chemical action in the continued presence of demineralizing agents with low pH. Erosion lesions on the labial surfaces of the maxillary and mandibular anterior teeth. CLASSIFICATION BASED ON ETIOLOGY Intrinsic erosion This is a form of erosion caused due to endogenous acids of gastric origin: I. Recurrent vomiting i. Eating disorders – Anorexia nervosa: This disorder is associated with extreme dietary restriction and profound weight loss. – Bulimia nervosa: This disorder is associated with repeated episodes of binge eating and self-induced vomiting.  These personality disorders are considered to be a major cause of dental erosion due to chronic vomiting. They are most commonly found in young women in the age of 20–30 years.  ii. Medical conditions – Gastrointestinal disorders - Peptic ulcer - Hiatus hernia - Intestinal obstructions – Metabolic and endocrine disorders  – Neurological disorders - Side effects of drugs - Psychogenic vomiting syndrome - Chronic alcoholism and binge drinking - Pregnancy-induced vomiting  II. GERD (Gastro Esophageal Reflux Disease) Regurgitation in this disease occurs without any nausea or abdominal contractions. Erosion occurs when the acid reflux passes into the pharynx and come into contact with the lingual surfaces of the teeth.  III. Rumination Rumination is a syndrome consisting of repetitive, effortless regurgitation of undigested food within minutes after a meal. This disorder is found in young infants.  Extrinsic erosion This is a form of erosion associated with extrinsic factors and the following are the common etiological causes of this kind of erosion: I. Occupational factors: Professional wine tasters II. Diet: Citrus fruit juices, acidic beverages and carbonated beverages III. Medicaments: Aspirin and ascorbic acid (vitamin C) IV. Lifestyle CLINICAL FEATURES Although erosive agents are the predominant causative factors, it is thought that toothbrushing and/or other abrasive agents in the diet may accelerate the loss of tooth structure, which is generally referred to as erosive tooth wear.  Regurgitation of stomach acid can cause this condition on the palatal surfaces of maxillary teeth (particularly anterior teeth). Extrinsic erosion commonly leads to the dissolution of the facial aspects of anterior and buccal aspects of posterior teeth. Erosion processes may also be involved in the loss of the tooth structure with a clinical presentation of ‘cupped-out’ areas on occlusal surfaces.  Exogenous acidic agents such as lemon juice (through sucking on lemons) may cause crescent-shaped or dished defects (rounded as opposed to angular) on the surfaces of exposed teeth (Fig. 20.2). Endogenous acidic agents such as gastric fluids cause generalized erosion on the lingual, incisal and occlusal surfaces. Consultation with a physician to obtain a proper diagnosis of GERD may assist in the diagnosis and management of erosion.  Other sources of erosion can be the use of sports drinks, herbal teas and vomiting associated with chemotherapy and, in the case of alcoholism, the presence of stomach contents in the mouth during periods of excessive alcohol consumption. The flow and buffering capacity of saliva are important factors in chemical erosion when other factors are present. ATTRITION Definition. Attrition is the mechanical wear of the incisal or occlusal surface as a result of functional or parafunctional movements of the mandible (tooth-to-tooth contacts) Attrition also includes proximal surface wear at the contact area because of physiologic tooth movement.  Etiology Habits are creating this problem, such as tooth grinding, or bruxism, usually resulting from: I. Stress II. Airway issues III. Sleep apnoea  Clinical Features I. In some older patients, the enamel of the cusp tips (or incisal edges) is worn off, resulting in cupped-out areas because the exposed, softer dentin wears faster than the surrounding enamel. II. Sometimes, these areas are an annoyance because of food retention or the presence of peripheral, sharp enamel edges.  III. Heavy occlusal loading from clenching may result in the presence of ‘craze lines’ which are limited to enamel (i.e. do not progress through the DEJ into dentin; Fig. 20.1F). Craze lines are not sensitive and do not require treatment but may be evidence of excessive masticatory muscle activity. IV. Slowing such wear by appropriate restorative treatment is indicated. The sharp edges can result in tongue or cheek biting; rounding these edges does not completely resolve the problem but does improve comfort. ABRASION Definition. Abrasion is the abnormal tooth surface loss resulting from direct forces of friction between teeth and external objects or from frictional forces between contacting teeth components in the presence of an abrasive medium.  Etiology Abrasion may occur from: I. Improper brushing habit: Factors influencing the role of tooth brushing in abrasion are: i. Brushing technique ii. Brushing force iii. Bristle stiffness iv. Time v. Frequency  II. Habitual chewing on hard objects (e.g. paper clips, pens, pencils) III. Chronic use of agents with high abrasivity (e.g. smokeless tobacco.  Clinical Features The loss of tooth structure in the cervical areas (abrasion) is commonly seen as a rounded notch in the gingival portion of the facial aspects of teeth. The surface of the defect is usually smooth. The presence of such defects does not automatically warrant intervention. It is important to determine and eliminate the cause (Fig. 20.4).  ABFRACTION Definition. Strong eccentric occlusal force resulting in microfractures at the cervical area of the tooth causing wedgeshaped defects is termed as abfraction (Fig. 20.5).  Etiology Teeth are not rigid structures and undergo deformation (strain) during normal loading. Intra-oral loads (forces) vary widely and have been reported to range from 10 N to 431 N, with a functional load of 70 N considered clinically normal. The number of teeth, type of occlusion and occlusal habits of patients (e.g. bruxism) affect the load per tooth. Abfraction is caused due to tooth flexure in patients with abnormal occlusal interactions. MECHANISM OF ABFRACTION Tooth flexure during abnormal occlusal interaction ↓ Lateral or axial bending of the tooth ↓ Tensile and compressive stresses generated in the cervical region ↓ Strain leading to microfractures in cervical enamel and tooth loss ↓ Notch shaped abfraction lesions  Clinical Features I. These lesions are characterized by sharp notch or wedgeshaped lesions instead of the saucer-shaped defects associated with other non- carious cervical lesions. II. The maximal abfractive stresses generated are at the cervical area in the thinnest region of enamel at the cementoenamel junction (CEJ). III. These forces can also cause the loss of bonded Class V restorations in preparations with no retention grooves.  Such fractures predispose enamel to loss when subjected to toothbrush abrasion and chemical erosion. This process may act as a key in the formation of some Class V defects. Additionally, in unbonded or leaking restorations, this flexure of dentin may produce changes in fluid flow and microleakage, leading to sensitivity and pulpal inflammation. TREATMENT OF ABRASION, EROSION, ABFRACTION AND ATTRITION Considerations for restorative management of non-carious lesions The defect is sufficiently deep to compromise the structural integrity of the tooth Intolerable sensitivity exists and is unresponsive to conservative desensitizing measures The area is affected by caries The defect contributes to a periodontal problem The area is to be involved in the design of a removable partial denture The depth of the defect is judged to be close to the pulp The defect is actively progressing The patient desires esthetic improvements Class V tooth preparation for abrasion and erosion lesions. (A) Preoperative notched lesion. (B to D) Beveling the enamel margin and roughening the internal walls, (E) Completed preparation with etched enamel.  The primary goal of management should be to halt or modify the etiology of the problem. The above considerations required for initiating restorative management of these lesions. Areas of significant occlusal attrition that have exposed dentin are sensitive, or annoying should be considered for restoration or at least protection from additional loss of tooth structure.  A treatment plan for definitive restorations must include an occlusal analysis (which requires articulated diagnostic models) as part of the comprehensive examination. Careful consideration of related information from the patient assessment and examination process is essential if all aspects of the etiology are to be identified and risk factors reduced.  Also, occlusal guard therapy should be considered for nocturnal protection of indirect restorations completed as a part of the definitive phase. The creation of an occlusal guard, for nocturnal use, may be indicated with a diagnosis of sleep-related bruxism.