Non-Carious Lesions PDF

Non-Carious Lesions Lesions involving hard tooth tissue destruction are mainly categorized into carious and non-carious lesions. These lesions result in loss of tooth structure that requires operative intervention. Dental caries, a bacterial infection, causes localized damage to tooth enamel. Acid-p...

Non-Carious Lesions Lesions involving hard tooth tissue destruction are mainly categorized into carious and non-carious lesions. These lesions result in loss of tooth structure that requires operative intervention. Dental caries, a bacterial infection, causes localized damage to tooth enamel. Acid-producing bacteria break down the tooth's mineral structure, leading to further decay. Caries involve cycles of demineralization and remineralization, where minerals in saliva or remineralizing solutions can help repair damaged areas. Understanding this balance is crucial for effective caries prevention and treatment. Caries can be classified by their type, location, severity, and progression rate. Primary caries develops on healthy teeth, while secondary caries occurs around existing fillings and can spread beneath them if the edges aren't properly sealed. Location of primary caries: There are three distinctly different clinical sites for caries initiation: Pits and fissures, which are the most susceptible sites. Smooth enamel surfaces that shelter plaque, which includes the area under the buccal and lingual height of contour and proximally under the contact area. Root surface The shape of pits and fissures makes them more prone to caries. These areas can trap plaque and bacteria, creating an ideal environment for decay. Caries begins as a small penetration point, following the direction of enamel rods until it reaches the dentin-enamel junction (DEJ). The DEJ offers the least resistance to decay, allowing it to spread laterally. Caries then progresses through dentin, reaching the pulp and causing dentin cavitation. This process results in two cone-shaped patterns of decay in enamel and dentin, with the base of each cone at the DEJ. Smooth Surface Caries: Unlike enamel defects, smooth surface caries begin in areas of enamel neglected due to poor oral hygiene and plaque buildup. When these lesions start, they follow the direction of enamel rods, forming a cone with its base at the enamel surface and its apex toward the DEJ. Lateral spread also occurs at the DEJ, leading to a cone-shaped pattern in dentin with its apex pulpally. Continued decay can result in dentin cavitation. 1 Root Caries: Root surfaces, being rougher than enamel, are more susceptible to plaque accumulation without proper oral hygiene. Root caries progress more rapidly than other types of caries because cementum is thin and offers minimal resistance to decay. They are more common in older individuals due to gingival recession Extent of Primary Caries: The earliest stage of enamel caries activity is incipient caries. This lesion is reversible and can be remineralized. However, the enamel surface is broken in cavitated caries, and the lesion has often progressed into dentin. At this stage, remineralization is impossible, and the caries are irreversible. Treatment typically involves tooth preparation and restoration. If the carious process is reversed, the caries becomes remineralized and is termed arrested caries. Rate (Speed) of Caries: Acute caries progress rapidly, causing swift tooth damage. Demineralization outpaces remineralization, resulting in a soft, light-colored lesion due to less time for external staining. Chronic caries, on the other hand, advance slowly, allowing for remineralization. This leads to a harder, darker lesion 2 Non-carious lesion: These are lesions of non-microbial origin that cause defects in tooth structures. 1. Abrasion: Definition: It is the pathologic surface loss of tooth structure resulting from direct frictional forces between the teeth and external objects, or from frictional forces between contacting teeth components in the presence of an abrasive medium. Types: a. Toothbrush abrasion is the most common example, where improper brushing techniques causes localized cervical lesions on the labial surface of teeth especially at the starting point of brushing. Toothbrush abrasion lesions are characterized by being i. Linear in outline, following the path of brush bristles. ii. The surface is extremely smooth and polished, and iii. The patient has very good oral hygiene b. Pipe-smoking depression abrasion occurring at the latero-anterior portion of the arch coinciding with the location of the pipe stem. c. Vigorous use of toothpicks between adjacent teeth can cause proximal abrasion. d. Certain occupational habits such as cutting sewing thread or holding nails with incisor teeth can create specific localized forms of abrasion e. Iatrogenic abrasion is that which is caused by faulty dentistry such as abrasion of opposing natural teeth with porcelain. An example is given in in which faulty upper partial denture with porcelain teeth caused abrasion of the lower natural teeth. 2. Erosion: Definition: It is the pathological loss of tooth structure resulting from chemico-mechanical action, mainly due to acids. Types: a. Exogenous acidic agents: Results from exogenous acids 1. Environmental factors: a. Contaminates of the working environment sometimes known as industrial acids by workers without proper safeguards b. Battery factory workers (exposed to sulfuric acid) c. Workers involved in other types of cleaning processes involving mainly sulfuric d. and hydrochloric acids. e. acidic water of swimming pools is a side effect of chlorination using chlorine gas that reacts with water to form hydrochloric acid. 2. Dietary factors: 3  Dietary acids are the principle causative factor for extrinsic erosion The most frequently consumed erosive acids are fruit acids and phosphoric acid contained in fresh fruits, fruit juices and soft drinks Acidic carbonated beverages. Salad dressing. Acidic fruit-flavored candies. Wines. 3. Medications: Low pH medicaments and oral hygiene products come in frequent and/or sustained contact with the dentition h as the potential to cause dental erosion. The increased use of vitamin C (ascorbic acid) More recently, vitamin C contained in all sorts of drinks, sports drinks and candies has been identified as a significant cause of extrinsic erosion 4. Lifestyle and Behavior factors: The type of food and beverage consumed, the frequency and time of consumption are lifestyle factors that were considered most important regarding the clinical development of dental erosion b. Endogenous acidic agents: such as gastric acids from frequent regurgitation, such as in bulimia. This causes generalized erosion of the palatal and occlusal surfaces of upper teeth. The mandibular teeth show less loss of enamel since it is partially protected by the tongue 3. Abfraction: Definition: Wedge shape cervical defect at CEJ that results from abnormally heavy forces as a result of unbalanced faulty occlusion. Normally, during mastication and function, the cervical part of the tooth is subjected to tooth flexure which induces compressive stresses during centric occlusion and tensile stresses during eccentric occlusion. It is hypothesized that in faulty occlusion, excessive compressive and tensile forces created during tooth flexure produces microfractures (abfractures) in the thin enamel at the cervical area. This leads to the characteristic wedge shape of such lesions. Once enamel is lost, dentin becomes subjected to various wear-causing factors. Abfraction could involve one tooth, e.g. rotated or mal-aligned tooth or many microfractures of enamel at cervical area teeth with parafunctional occlusion. Such lesions are usually associated with wear facets. 4. Attrition: Definition: It is the mechanical wear of the incisal or occlusal tooth structure resulting from direct frictional forces between contacting teeth. It is a physiological, continuous, age-dependant process. it could be accelerated by pathological parafunctional mandibular movements, e.g. in bruxism (stressful tooth grinding). Attrition affects occluding surfaces resulting in flattening of their inclined planes and in facet formation. 4  In severe cases, enamel of the cusp tips (or incisal edges) is worn off and dentin is exposed. It could also lead to loss of vertical dimensions of teeth. Attrition also affects proximal contact areas, leading to flat proximal contours and decreased mesio-distal dimensions of teeth 5. Enamel hypoplasia: It is a defect in enamel due to improper enamel matrix formation due to injury of ameloblasts during enamel formation. This leads to defective areas in enamel. It is usually seen on anterior teeth and first molars in the form of opaque white or brownish areas or pitted and grooved enamel which is usually hard and discolored. In severe cases, depressions or loss of a segment of enamel may occur. 6. Enamel hypocalcification: It is a defect in enamel due to improper mineralization of the enamel due to injury to ameloblasts, i.e. the injury of ameloblasts occurs during mineralization of the formed matrix not during formation of the matrix as in hypoplasia. Thus, the affected areas will not be defective in any way, but they will appear chalky white. The defect could vary from isolated pits to widespread linear defects or patches. 7. Discoloration: It is a deviation from the normal tooth shade and color of an individual. Although it is not destructive, yet it has a far-reaching effect on the affected individual, both socially and psychologically. Discoloring changes of dentin may also result from medicaments administered by pregnant females during the stages of tooth formation of the infant, for example Tetracycline staining. The resulting discoloration ranges from grayish-yellow to gray-brown or dark-brown Intrinsic discoloration can also result from pigmentation of non-vital teeth following pulpal necrosis. This will cause grayish to dark-black discoloration 8. Fracture: Definition: It is separation and/or loss of tooth structure as a result of trauma from a fall, a blow or sudden biting on a hard unyielding substance Traumatic injuries to natural teeth crowns range from simple fractures of enamel (chipping), to fracture of enamel and dentin with or without pulp involvement, to total loss of crown structures. Trauma can also lead to total avulsion of the tooth, fracture of tooth root or displacement of affected tooth. In addition, weakened teeth may split under normal masticatory forces when biting on a hard object. 5