03 - Cariology and Rubber Dam Placement

pit and fissure caries

begin in caries prone pit and fissures where there is incomplete fusion of enamel lobes during tooth development

smooth surface caries

occur on smooth surfaces of anatomic crown of a tooth in locations that are not readily available to the natural cleansing ability of the cheeks, lips, and tongue

• inaccessible proximal surfaces of crowns cervical to aproximal contact

• inaccessible proximal surfaces of crowns on gingival third of facial and lingual surfaces, cervical to height of contour of crown

root surface caries

type of smooth surface caries that begins when cementum gets exposed to caries-forming plaque

progression of decay in enamel

demineralization process occurs in direction parallel to enamel rods

• pit and fissure caries → caries pattern resembles a triangle or cone, where apex is directed toward enamel surface and base at DEJ

• smooth surface caries → base of triangle or cone is on the enamel surface and apex is at the DEJ

progression of decay in dentin

dentin is less mineralized than enamel, where decay spreads laterally along DEJ when acid attacks dentin

• pattern of caries in dentin is a triangular or cone shape with the base at the DEJ but the apex is towards the pulp

• caries spreads more rapidly in dentin

cause of dental caries

• host tooth surface

• bacteria

  • Streptococcus mutans and lactobacilli firmly adhere to tooth surface in layer of microbial biofilm called dental plaque

• substrate/carbs

  • bacteria eat carbohydrates and create a byproduct of lactic acid that acts on tooth structure and causes demineralization

• time

  • cavity forms if enough acid is produced and enough minerals are lost

acidic environment

caries influenced by acidity of its biofilm, which is influenced by the acidity of ingested foods and beverages

• more acid = more demineralization

remineralization

reverse of decay process if certain minerals like calcium and fluoride are available for uptake

saliva

saliva bathes teeth in minerals like calcium that improves remineralization, as well as washes away food particles

fluoride

fluoride applied to teeth in appropriate concentrations can reduce dental caries incidence by increasing the tooth’s resistance to breakdown by caries forming acid

teeth isolation

isolate teeth for:

• access and visibility

• better patient protection

• control moisture in operating field

• decrease operating time

steps for placing rubber dam

1. ink stamp to imprint rubber dam with holes

2. rubber dam punch to place appropriately sized holes in rubber dam

3. choose appropriate rubber dam clamp and floss through both holes on wings of clamp

4. place rubber dam on frame

5. place clamp through appropriate hole in rubber dam

6. tie floss to sides of frame

7. use forceps to expand clamp and place on tooth posterior to the tooth you are working on

8. pass floss into interproximal areas to force rubber dam between teeth

9. place rubber dam wedget to secure the unclamped end of rubber dam

10. invert rubber dam around each tooth facially and lingually, and invert rubber dam around clamp

limitations to rubber dam

• patient allergy to rubber dam material

• medically limited patients

  • COPD

  • coughing

  • psychological issues (claustrophobia)