Dental Caries

Copyright © 2005 by Elsevier Inc. All rights reserved. “The mouth is the gateway to the rest of the body, a mirror of our overall well-being.” Harold C. Slavkin, D.D.S. Former Director of the National Institute of Dental and Craniofacial Research, and Dean of the University of Southern California School of Dentistry

Copyright © 2005 by Elsevier Inc. All rights reserved. Everyday in the United States, millions of people including children, working families, and the elderly live in constant pain as a result of oral disease or injury to the mouth.

Copyright © 2005 by Elsevier Inc. All rights reserved. Introduction Dental caries is an infectious bacterial disease that has plagued humans since the beginning of recorded history. What is dental caries? Simply stated, it is tooth decay. Today, because of scientific advances and new technologies, dentistry is developing new strategies for managing dental caries. These strategies emphasize prevention and early intervention.

Copyright © 2005 by Elsevier Inc. All rights reserved. You cannot be healthy without oral health. Oral health and general health should not be interpreted as separate entities. Oral health is a critical component of health.

Copyright © 2005 by Elsevier Inc. All rights reserved. Dental Caries: A Bacterial Infection There are two specific groups of bacteria found in the mouth that are responsible for dental caries: –Mutans streptococci (Streptococcus mutans) –Lactobacilli They are found in relatively large numbers in the dental plaque. The presence of lactobacilli in the mouth indicates a high sugar intake.

Copyright © 2005 by Elsevier Inc. All rights reserved. Transmission of Caries Causing Bacteria Mutans streptococci are transmitted through saliva, most frequently the mother’s, to the infant. When mothers have high counts of mutans streptococci in their mouths, the babies also have high counts of the same bacteria in their mouth. Women should be certain their own mouths are healthy. When the number of caries causing bacteria in the mouth increases, the risk for developing dental caries also increases.

Copyright © 2005 by Elsevier Inc. All rights reserved. Dental Plaque Dental plaque is a colorless, soft, sticky coating that adheres to the teeth. Plaque remains attached to the tooth despite movements of the tongue, water rinsing, water spray, or less than thorough brushing. Formation of plaque on a tooth concentrates millions of microorganisms on that tooth.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Dental plaque made visible with disclosing agent

Copyright © 2005 by Elsevier Inc. All rights reserved. Structure of Enamel Enamel is the most highly mineralized tissue in the body. Enamel is stronger than bone. Enamel consists of microscopic crystals of hydroxapatite arranged in structural layers or rods, also known as prisms. The enamel crystals are surrounded by water. The water and protein components in the tooth are important because that is how the acids travel into the tooth and the minerals travel out and the tooth structure dissolves.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Dental caries

Copyright © 2005 by Elsevier Inc. All rights reserved. The Caries Process For caries to develop, three factors must occur at the same time: –A susceptible tooth –Diet rich in fermentable carbohydrates –Specific bacteria (regardless of other factors, caries cannot occur without bacteria)

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Dental caries (Courtesy Ivoclar, Vivadent, Amhurst, NY.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Areas for Development of Caries Pit and fissure caries occurs primarily on the occlusal surfaces and buccal and lingual grooves of posterior teeth, as well as in lingual pits of the maxillary incisors. Smooth surface caries occurs on intact enamel other than pits and fissures. Root surface caries occurs on any surface of the root. Secondary, or recurrent, caries occurs on the tooth surrounding a restoration.

Copyright © 2005 by Elsevier Inc. All rights reserved. Stages of Caries Development It usually takes a period of time, from months to years, for a carious lesion to develop. It is an ongoing process, characterized by alternating periods of demineralization and remineralization. –Demineralization is the dissolving of the calcium and phosphate from the hydroxyapatite crystals. –Remineralization is the calcium and phosphate being redeposited in previously demineralized areas. It is possible to have the processes of demineralization and remineralization occur without any loss of tooth structure.

Copyright © 2005 by Elsevier Inc. All rights reserved. Stages of Caries Development-cont’d Incipient lesion develops in the earliest stages when caries begins to demineralize the enamel. Overt, or frank, lesion is characterized by cavitation (the development of a cavity or hole in the tooth). Rampant: The time between the onset of the incipient lesion and the development of the cavity is rapid and there are multiple lesions throughout the mouth.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig A, The earliest sign of decay is decalcification (Courtesy Dr. John Featherstone, University of California, San Francisco, School of Dentistry.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig B, Dental caries (Courtesy Dr. Frank Hodges, Santa Rosa, CA.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig C, Dental caries (Courtesy Dr. Frank Hodges, Santa Rosa, CA.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Severely decayed molar on a child

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Decay on the lingual of a maxillary lateral incisor

Copyright © 2005 by Elsevier Inc. All rights reserved. Root Caries Root caries is becoming more prevalent and is a concern for the elderly population who often have gingival recession exposing the root surfaces. People are living longer and keeping their teeth longer. Older people are often taking medications known to reduce salivary flow. Carious lesions form more quickly on root surfaces than coronal caries because the cementum on the root surface is softer than enamel and dentin. Like coronal caries, root caries has periods of demineralization and remineralization.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Root caries (Courtesy Dr. John Featherstone, University of California, San Francisco, School of Dentistry.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Secondary, or Recurrent, Caries Secondary, or recurrent, caries starts to form in the small spaces or gaps between the tooth and the margins of a restoration. Bacteria are able to thrive in these areas. When dental restorations need to be replaced, it is because there is recurrent caries under the existing restoration. New restorative materials that are bonded to the tooth structure eliminate the gap between tooth and filling where microleakage can occur. Restorative materials that slowly release fluoride help to prevent secondary caries.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Recurrent caries under an amalgam restoration

Copyright © 2005 by Elsevier Inc. All rights reserved. The Role of Saliva Physical protection provides a cleansing effect. Thick, or viscous, saliva is less effective than a more watery saliva in clearing carbohydrates. Chemical protection contains calcium, phosphate, and fluoride. It keeps calcium there ready to be used during remineralization. It includes buffers, bicarbonate, phosphate, and small proteins that neutralize the acids after we ingest fermentable carbohydrates. Antibacterial substances in saliva work against the bacteria. If salivary function is reduced for any reason, such as from illness or medications or due to radiation therapy, the teeth are at increased risk for decay.

Copyright © 2005 by Elsevier Inc. All rights reserved. Diagnosis of Dental Caries Detectable explorer “stick” Radiographs Visual Laser caries detector

Copyright © 2005 by Elsevier Inc. All rights reserved. Laser Caries Detector The laser caries detector is used to diagnose caries and reveal bacterial activity under the enamel surface. Carious tooth structure is less dense and gives off a higher reading than non- carious tooth structure.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Visual and radiographic appearance of seemingly intact molar

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Cross section of molar showing decay

Copyright © 2005 by Elsevier Inc. All rights reserved. Methods of Caries Intervention Fluoride: A variety of types are available to strengthen the tooth against solubility to acid. Antibacterial therapy: Products such as chlorhexidine rinses are effective. Fermentable carbohydrates: Reduce the amount and frequency of ingestion. Salivary flow can be increased by chewing sugarless gum, for example, those with a non- sugar sweetener such as xylitol.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Preventive measures against caries. A, Fluoride rinse. B, Chlorhexidine rinse. C, Xylitol gum.

Copyright © 2005 by Elsevier Inc. All rights reserved. Risk Assessment for Dental Caries If the patient’s risk for developing dental caries can be determined, it is possible to prevent the caries from developing by beginning appropriate preventive treatment. Caries risk assessment tests are based on the amount of mutans streptococci and lactobacilli present in the saliva. High bacterial counts indicate a high caries risk, low counts indicate a low risk for caries. If the preventive measures are not provided, carious lesions are likely to develop.

Copyright © 2005 by Elsevier Inc. All rights reserved. Indication for Using a Caries Risk Test New patients with signs of caries activity Pregnant patients Patients experiencing sudden increase in incidence of caries Individuals taking medications that may affect the flow of saliva Xerostomic patients

Copyright © 2005 by Elsevier Inc. All rights reserved. Indication for Using a Caries Risk Test-cont’d Patients about to undergo chemotherapy Patients who consume fermentable carbohydrates frequently Patients suffering from diseases of the autoimmune system

Copyright © 2005 by Elsevier Inc. All rights reserved. Periodontal Diseases Chapter 14

Copyright © 2005 by Elsevier Inc. All rights reserved. Introduction Periodontal disease is an infectious disease process that involves inflammation. Periodontal diseases involve the structures of the periodontium. Periodontal disease can cause a breakdown of the periodontium resulting in loss of tissue attachment and destruction of the alveolar bone.

Copyright © 2005 by Elsevier Inc. All rights reserved. Prevalence of Periodontal Disease Periodontal diseases are the leading cause of tooth loss in adults. Almost 75% of American adults have some form of periodontal disease, and most are unaware of the condition. Almost all adults and many children have calculus on their teeth. Fortunately, with the early detection and treatment of periodontal disease, most people can keep their teeth for life.

Copyright © 2005 by Elsevier Inc. All rights reserved. Systemic Conditions: Links to Periodontal Disease Certain systemic conditions increase the patient’s susceptibility to periodontal disease, and periodontal disease may actually increase a patient’s susceptibility to certain systemic conditions. –Cardiovascular disease –Preterm low birthweight –Respiratory disease

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Structures of the periodontium: junctional epithelium, gingival sulcus, periodontal ligaments, and cementum

Copyright © 2005 by Elsevier Inc. All rights reserved. Periodontal Diseases Infectious diseases that are the leading cause of tooth loss in adults. Nearly 75% of American adults suffer from various forms of periodontal disease and most are unaware of it. Almost all adults have calculus on their teeth. With the early detection and treatment of periodontal disease, it is possible for most people to keep their teeth for a lifetime.

Copyright © 2005 by Elsevier Inc. All rights reserved. Causes of Periodontal Diseases Dental plaque is the major factor in causing periodontal disease. Dental calculus provides a surface for plaque to attach. –Subgingival calculus –Supragingival calculus

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Buildup of bacterial plaque on the teeth affects the gingival tissues

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Periodontal disease (Courtesy Dr. Edward J. Taggart, San Francisco, CA.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Types of Periodontal Diseases Periodontal disease is an inclusive term describing any disease of the periodontium. Gingival diseases and periodontitis are the two basic forms of periodontal disease, and each has a variety of forms.

Copyright © 2005 by Elsevier Inc. All rights reserved. Gingival Diseases Gingivitis is inflammation of the gingival tissue. Gingivitis is characterized by areas of redness and swelling, and there is a tendency for the gingiva to bleed easily. Gingivitis is limited to the epithelium and gingival connective tissues. –It is important to note that there is no tissue recession or loss of connective tissue or bone.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Marginal gingivitis

Copyright © 2005 by Elsevier Inc. All rights reserved. Other Types of Gingivitis Other types of gingivitis are associated with: – Puberty – Pregnancy – Use of birth control medications Gingivitis is painless and often unrecognized until a dental professional emphasizes its importance. Improved daily oral hygiene practices will reverse gingivitis.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Medication-induced gingivitis (From Perry D, Beemsterboer P, Taggart E: Periodontology for the dental hygienist, Philadelphia, 2001, Saunders.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Pregnancy gingivitis (From Perry D, Beemsterboer P, Taggart E: Periodontology for the dental hygienist, Philadelphia, 2001, Saunders.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Periodontitis Periodontitis means inflammation of the supporting tissues of the teeth. Periodontitis is the extension of the inflammatory process from the gingiva into the connective tissue and alveolar bone that supports the teeth. The progression of periodontitis involves the destruction of connective tissue attachment at the most apical portion of a periodontal pocket.

Copyright © 2005 by Elsevier Inc. All rights reserved. Risk Factors for Periodontal Disease Smoking Diabetes Poor Oral Hygiene Osteoporosis HIV/AIDS Medications Stress

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Cross section of a tooth and associated anatomic structures. A, Illustrates the depth of a normal gingival sulcus. B, Illustrates a periodontal pocket.

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig The arrows indicate varying amounts of bone loss due to periodontal disease (From Miles DA et al: Radiographic imaging for dental auxiliaries, ed 3, Philadelphia, 1999, Saunders.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Fig Generalized juvenile periodontitis (From Perry D, Beemsterboer P, Taggart E: Periodontology for the dental hygienist, Philadelphia, 2001, Saunders.)

Copyright © 2005 by Elsevier Inc. All rights reserved. Signs and Symptoms of Periodontal Disease Red, swollen, or tender gingiva Bleeding gingiva while brushing or flossing Loose or separating teeth Pain or pressure when chewing Pus around the teeth or gingiva