fluoride at the periphery of a carious lesion?
4. Why is it useful to consider the pulp and dentin as one biological unit?
5. What is the clinical significance of the high concentration of dentinal tubules in root dentin?
6. What factors alter the permeability of dentin?
7. What zones of caries have been described in dentin, and how can you account for them?
8. What is the clinical significance of discriminating between infected and affected dentin?
9. How does the pulp–dentin develop a mineral barrier to caries?
10. What is the likely consequence of some bacteria remaining in a sealed cavity?
11. Why does the rate of caries progression in dentin differ from enamel?
12. What is the difference between biomineralization and dissolution/precipitation?
References
[1] Kidd EA, Joyston-Bechal S, Beighton D. The use of a caries detector dye during cavity preparation: a microbiological assessment. Br Dent J 1993; 174(7):245–248
[2] Kidd EA. How ‘clean’ must a cavity be before restoration? Caries Res 2004; 38(3):305–313
[3] Ricketts D. Deep or partial caries removal: which is best? Evid Based Dent 2008; 9(3):71–72
[4] Massler M, Pawlak J. The affected and infected pulp. Oral Surg Oral Med Oral Pathol 1977; 43(6):929–947
[5] Daculsi G, LeGeros RZ, Jean A, Kerebel B. Possible physico-chemical processes in human dentin caries. J Dent Res 1987; 66(8):1356–1359
[6] Zavgorodniy AV, Rohanizadeh R, Bulcock S, Swain MV. Ultrastructural observations and growth of occluding crystals in carious dentine. Acta Biomater 2008; 4(5):1427–1439
[7] Schröder U. Effects of calcium hydroxide-containing pulp-capping agents on pulp cell migration, proliferation, and differentiation. J Dent Res 1985; 64 (Spec No):541–548
Suggested Readings
Berkowitz BWK, Moxham BJ, Linden RWA, Sloan AJ. Oral biology; oral anatomy histology, physiology and biochemistry. London: Churchill Livingstone; 2010
Brookes SJ, Robinson C, Kirkham J, Bonass WA. Biochemistry and molecular biology of amelogenin proteins of developing dental enamel. Arch Oral Biol 1995; 40(1):1–14
Charadram N, Austin C, Trimby P, Simonian M, Swain MV, Hunter N. Structural analysis of reactionary dentin formed in response to polymicrobial invasion. J Struct Biol 2013; 181(3):207–222
Featherstone JD. The continuum of dental caries—evidence for a dynamic disease process. J Dent Res 2004; 83(Spec No C):C39–C42
Kidd EA, Joyston-Bechal S. The essentials of dental caries. Bristol: Wright; 1987
Pashley DH. Dentin permeability, dentin sensitivity, and treatment through tubule occlusion. J Endod 1986; 12(10):465–474
Sloan AJ, Smith AJ. Stem cells and the dental pulp: potential roles in dentine regeneration and repair. Oral Dis 2007; 13(2):151–157
Stahl J, Zandona AF. Rationale and protocol for the treatment of non-cavitated smooth surface carious lesions. Gen Dent 2007; 55(2):105–111
3 Oral Mucosa and Periodontium
Regional Variation of Oral Mucosa
Abstract
Into this chapter are grouped the soft tissues of the mouth and the tooth-supporting tissues. The oral mucosa varies from the thin, fragile lining of the floor of the mouth to the rugged masticatory mucosa of the tongue and hard palate. These tough mucosal surfaces may have to withstand the rigors of masticating hard food. The periodontium which includes the structures supporting the teeth is of great importance to dentists. When it is infected and the tissue destroyed, the teeth may literally fall out. And notwithstanding all the progress in treating periodontal disease, it remains resistant to treatment in many patients. The junction between the tooth root and the supporting tissues provides a potential route of entry of bacteria into the body, which is unusual; all other external openings of the body are lined with epithelium with the exception of the fallopian tubes. The teeth are not held rigidly in their sockets like reptilian or fish teeth. They are able to move slightly in function and have the capacity to reposition as they erupt and drift when unsupported by neighbors or opposing teeth. An understanding of the dynamic structures of tooth support is essential to understanding the response of the periodontium to infection.
Keywords: oral mucosa, oral epithelium, lamina propria, masticatory mucosa, gingiva, periodontium, epithelial attachment, junctional epithelium, cementum
3.1 Structure of Oral Mucosa
The oral mucosa is the tissue lining the mouth. The two major layers of the oral mucosa, the oral epithelium and the lamina propria, are equivalent to the epidermis and dermis of the skin.
3.1.1 Oral Epithelium
The oral epithelium is a stratified layer of squamous cells which may either be keratinized or nonkeratinized. The characteristics of the individual layers (i.e., basal, prickle, granular, and keratin) are similar to those seen in the skin. Most of the cells of the epithelium are keratocytes. As they mature and are pushed to the surface by dividing cells in the basal layer, they will fill with keratohyalin granules and finally keratin.
There are three other types of cell in the epithelium.
• The melanocytes produce pigment and transfer it to the keratocytes around them. The number of melanocytes is no greater in heavily pigmented epithelium, but their activity is increased.
•
