Operative Dentistry 2017 PDF

2017  Dental caries lesion DEFINITION: It is a disease of the calcified tissues of the teeth, characterized by a demineralization of the inorganic portion and destruction of the organic substance of the tooth” For dental caries to occur a bacterial biofilm has to acc...

2017  Dental caries lesion DEFINITION: It is a disease of the calcified tissues of the teeth, characterized by a demineralization of the inorganic portion and destruction of the organic substance of the tooth” For dental caries to occur a bacterial biofilm has to accumulate on a tooth surface. The bacteria within the biofilm metabolize dietary sugar substrates producing acids which, over time, lead to demineralization of the tooth tissue. DENTAL CARIES IS A MULTIFACTORIAL DISEASE????  Factors of Tooth substrate/Host – Variation in morphology Developmental defects in enamel may result in increase the caries risk by increase plaque retention, increase bacterial Colonization. Furthermore the loss of enamel make it more susceptible to tooth demineralization. Physical characteristics of teeth like deep and narrow occlusal fissures, deep buccal or lingual pits and enamel hypoplasia, etc. affect the initiation of dental caries. The shape, size and order of the teeth which affects the cleaning effects of saliva. – Position. When the tooth is out of position, rotated or in any abnormal position, it becomes difficult to clean, and hence retains more food and debris.  Dental Plaque/Biofilm Dental plaque is an adherent deposit of bacteria and their products, which forms on all tooth surfaces. Glucan is insoluble gel plaque adhere to tooth and act as a barrier against diffusion salivary buffers. Glucan mediated biofilms are more resistant to mechanical removal Allows the cariogenic bacteria to stick onto the teeth and form a biofilm Bacteria in these biofilms are more resistant to antimicrobial treatments  The “cariogenic bacteria” Bacteria associated with dental caries Mutans streptococci (S. mutans) – caries initiation Actinomyces – early colonizers and root caries Lactobacilli (L. casei) – caries progression Acid production (acidogenicity) Lower the pH to below 5.5, the critical pH. Drives the dissolution of calcium phosphate (hydroxyapatite) of the tooth enamel Inhibit the growth of beneficial bacteria, promote the growth of aciduric bacteria. Further lower the pH, promote progression of the carious lesion.  Diet and time Once sugar is consumed, the bacteria within the biofilm are able to produce acid, resulting in a rapid fall in plaque pH. When this falls below a critical pH, often considered to be in the region of pH 5.5, the plaque fluid becomes undersaturated with respect to tooth mineral, and demineralization of the tooth occurs. A subsequent sugar snack may cause another dip in pH. Frequent sugar intakes may keep the biofilm undersaturated with respect to tooth mineral and below the critical pH for several hours each day. Sticky, sugary foods may also remain around the teeth for prolonged periods of time and have a similar effect.  pH pH is a factor in demineralization and remineralization Demineralization: mineral salts dissolve into the surrounding salivary fluid: enamel at approximate pH of 5.5 or lower dentin at approximate pH of 6.5 or lower Remineralization: pH comes back to neutral (7) saliva-rich calcium and phosphates minerals penetrate the damaged enamel surface and repair it: enamel pH is above 5.5 dentin pH is above 6.5  Enviromental Factors related to Substrate Saliva - In its absence, there can be devastating effects, which include difficulty with mastication, swallowing and speech, loss of taste, oral soreness, a feeling of thirst and widespread rampant caries. The feeling of a dry mouth, or xerostomia, is usually a result of hyposalivation or oral dryness.  Enviromental Factors related to Substrate Saliva  Composition of saliva and its Functions Lysozyme, lactoperoxides, mucins, immunoglobulins function is anti microbial action Water, mucins, electrolytes function is Maintaining mucosa integrity Mucin, glycoproteins, water function is Lubrication Water function is cleansing Bicarbonate, phosphate, calcium, fluorides Function is Buffer capacity and remineralization  Viscosity and flow rat When salivary flow is reduced, salivary buffering capacity is lost, an acid environment is encouraged which further promotes the growth of aciduric bacteria.  FLUORIDE The presence of fluoride during tooth development, maturation of enamel or during the remineralization process resulting in decreased enamel solubility (more fluorapatite). This results in decreased enamel demineralization and enhances remineralization. The replacement of hydroxyl ions in the crystal by fluoride makes it more acid resistant. Formation of fluoroapatite (less soluble than hydroxyapatite) Inhibits demineralization Induces remineralization Inhibits bacterial metabolism Inhibits plaque formation Reduces “Wettability of surfaces of tooth”. Formation of dental caries Progression of dental caries Normal tooth ↓ White chalky spot ↓ Incipient lesion ↓ Cavitation ↓ If not treated ↓ Involvement of dentin and pulp ↓ Pulp inflammation ↓ Pulp necrosis Periradicular lesion  CARIES sites Carious lesions can form on any tooth surface exposed to the mouth; thus they can form on enamel, cementum, or dentine. The following sites particularly favour plaque retention: enamel pits and fissures approximal enamel smooth surfaces just cervical to the contact area the enamel at the cervical margin of the tooth at the gingival margin or on the exposed root incase of gingival recession. the margins of restorations, particularly where there is a wide gap between the restoration and the tooth or those where the restoration overhangs the margin of the cavity.  CLASSIFICATION OF DENTAL CARIES Carious lesions can be classified in different ways. According to Their Anatomical Site Pit and fissure caries: occur on occlusal surface of posterior teeth and buccal and lingual surfaces of molars and on lingual surface of maxillary incisors. Smooth surface caries: Smooth surface caries occurs on gingival third of buccal and lingual surfaces and on proximal surfaces. Root caries: When the lesion starts at the exposed root cementum and dentin, it is termed as root caries.  CLASSIFICATION OF DENTAL CARIES According to Whether It is a New Lesion or Recurrent Carious Lesion Primary caries: It denotes lesions on unrestored surfaces. Recurrent caries: Lesions developing adjacent to fillings are referred to as either recurrent or secondary caries. Residual caries: It is demineralized tissue left in place before a filling is placed.  CLASSIFICATION OF DENTAL CARIES According to the Activity of Carious Lesion Active carious lesion: A progressive lesion is described as an active carious lesion. Inactive/arrested carious lesion: A lesion that may have formed earlier and then stopped is referred to as an arrested or inactive carious lesion. Arrested carious lesion is characterized by a large open cavity which no longer retains food and becomes self-cleansing.  CLASSIFICATION OF DENTAL CARIES According to Speed of Caries Progression 1. Acute dental caries: Acute caries travels towards the pulp at a very fast speed. 2. Chronic dental caries: Chronic caries travel very slowly towards the pulp. They appear dark in color and hard in consistency. 3. Rampant caries: It is the name given to multiple active carious lesions occurring in the same patient, frequently involving surfaces of teeth that are usually caries free.  CLASSIFICATION OF DENTAL CARIES Rampant caries is of following three types: 1. Early childhood caries: It is a term used to describe dental caries present in the primary dentition of young children. 2. Bottle caries or nursing caries: these are names used to describe a particular form of rampant caries in the primary dentition of infants and young children. the clinical pattern is characteristic, with the four maxillary deciduous incisors most severely affected. 3. Xerostomia induced rampant caries (radiation rampant caries): these are commonly observed that after radiotherapy of malignant areas of or near the salivary glands. Because of radiotherapy salivary flow is very much reduced. This results in rampant caries even in those teeth which were free from caries before radiotherapy.  CLASSIFICATION OF DENTAL CARIES Based on Number of Tooth Surfaces Involved Simple caries: Caries involving only one tooth surface Compound caries: If two surfaces are involved Complex caries: If more than two surfaces are involved Classification According to the Severity Incipient caries: It involves less than half the thickness of enamel Moderate caries: It involves more than half the thickness of enamel, but does not involve dentinoenamel junction. Advanced caries: It involves the dentinoenamel junction and less than half distance to pulp cavity. Severe caries: It involves more than half distance to pulp cavity.  Caries diagnosis The prerequisites for caries diagnosis are: good lighting clean teeth tooth view on both wet and dry sharp eyes with vision aided by magnification. reproducible bitewing radiographs.  Caries diagnosis Transmitted light can also be of considerable assistance in the diagnosis of approximal caries, particularly in anterior teeth. A number of caries detection devices have been invented to aid detection and monitoring of early carious lesions;or example, the laser fluorescence devices, the DIAGNOdent and the newer DIAGNOdent pen PREVENTION OF DENTAL CARIES  PREVENTION OF DENTAL CARIES Method of dental caries control can be classified into two types: 1. Methods to reduce demineralizing factors - Dietary measures - Methods to improve oral hygiene - Chemical measures. 2. Methods to increase protective factors - Methods to improve flow, quantity and quality of saliva - Chemicals altering the tooth surface or tooth structure: Fluorides - Application of remineralizing agents - Use of pit and fissure sealants.  Oral hygiene Dental prophylaxis: In dental prophylaxis, polishing of roughened tooth surfaces and replacement of faulty restorations is done so as to decrease the formation of dental plaque, therefore, resulting in less incidence of caries. Tooth brushing: Nowadays, tooth brushing and other mechanical cleaning procedures are considered to be the most reliable means of controlling plaque and provide clean tooth surface. But variations exist in design of toothbrush, brushing techniques, frequency of brushing and brushing time. Substances interfering with bacterial growth and metabolism – Chlorhexidine – Iodine – Glutaraldehyde  Pit and fissure sealants Advantages of Seal pits and fissures mechanically making them resistant to food impaction Make pits and fissures self-cleansable Halt incipient carious lesion. Patient and tooth selection In children with medical, physical or intellectual impairment In children with signs of acute caries activity Children and young people with no signs of caries activity but having potentially susceptible areas like deep fissures.  Caries prevention Fluoride Treatment Modalities Concentrati Caries Route Method on (PPM) Reduction % Systemic Public Water Supply 1 50 – 60 % Topical Self Application 225 30 – 40 % Low dose/ high frequency rinses (0.05 NaF daily) High Potency/Low frequency rinses (0.2 NaF 30 – 40 900 weekly) after 2 years Fluoride dentifrices (daily) 1000 20 Professional application Acidulated Phosphate fluoride gel (1.23) annually 12,300 40 - 50 or semiannually NaF solution (2 %) 20.000 40 – 50 NaF solution (8 %) 80.000 40 - 50  Caries prevention Method & Indication Rationale Technique & Materials A. Limit Substrate Indication : Reduce nu., duration and Eliminate Sucrose inbetween Frequent Sucrose exposure intensity of Acid attacks meals. Poor quality Diet Reduce or eliminate Sucrose from meals. B. Modify Microflora Indication : Intensive Antimicrobial Tx. Chlorhexidine mouthrinse High MS Count Topical F Tx. High Lactobacillus Count AB Tx. (Vancomycine, Tetracycline) A. Plaque Disruption Indication : Prevent plaque succession Brushing High Plaque score Decrease plaque mass Flossing Puffy red gingiva Promote buffering Other OH aid as necessary High bleeding point score  Caries prevention Method & Indication Rationale Technique & Materials D. Modify Tooth Surface Indication : Increase resistance to Systemic Fluoride Incipient Lesion demineralization. Topical Fluoride Surface Roughening Decrease plaque retention Smoothen the surface E. Stimulate Salivary flow Indication : Increases Clearance of Eat noncariogenic foods Dry mouth with little Saliva substrate and acid. Sugarless Chewing Gum Red mucosa Promote Buffering Medications to stimulate Medication reduces Salivary Salivary flow. flow. F. Restore Tooth Surface Indication: Eliminate MS & Restore all cavitated lesions. Cavitated lesions lactobacillus infection. Seal Pit & Fissures Pits & fissures at caries risk Deny habitat for MS for Correct all teeth defects Defective Restoration reinfection.