Final corrected 16-17 Operative (2)

rubber damThe two most frequently quoted disadvantages of using the rubber dam are:• Time consumption• Patient objection• Cost• Staff allergies to material 100 copyright © 2016-2017 Dental DecksOPERATIVE

• Time consumption • Patient objection*** However, if you become proficient in placing the rubber dam and explain to patientsthe advantages of using it, these claims will be eliminated.Advantages of using the rubber dam: • Dry, clean field • Access and visibility • Improved properties of dental materials • Protection of the patient and the operator • Operating efficiencyThe following conditions may preclude the use of the rubber dam: • Severely tilted teeth • Some third molars • Teeth that are not erupted sufficiently • Some respiratory problems, such as asthma or severe colds, in which breathing through the nose is difficultRemember: The use of a rubber dam is the standard of care when performingendodontics.

rubber damThe rubber dam can still be used effectively even if teeth are crowded andoverlapped because the hole punch pattern does not always have to be followed.• Both the statement and the reason are correct and related• Both the statement and the reason are correct but not related• The statement is correct, but the reason is not• The statement is not correct, but the reason is correct• Neither the statement nor the reason is correct 101 copyright © 2016-2017 Dental DecksOPERATIVE

• Both the statement and the reason are correct and relatedIn this case, you can punch the holes closer or in a similar pattern to the teeth, allowingfor the elimination of wrinkles and avoid having papillae protruding through.Five functions of rubber dam isolation: • Retracts soft tissue, such as lips, cheeks, and tongue • Provides for clean, dry field • Protects the patient by eliminating the possibility of swallowing debris or instru- ments. Protects the dentist somewhat by isolating him/her from possible infectious conditions in the patient’s mouth. • Provides for maximum physical properties of materials. For example: The rubber dam provides a dry field, which is essential for placement of amalgam restorations as well as cements. Remember, the cements that are placed under dry conditions have maximum strength. Also, a dry field prevents delayed expansion of amalgam. • Saves time — rubber dam saves time because the operator can work more efficiently in a clean, dry field where visibility is not impaired.Important: For or a rubber dam clamp to be stable, all four points of the jaws of theclamp must contact the tooth gingival to the height of contour. They should not extendbeyond the line angles to prevent impingement of the interdental papilla and possibleinterference with placement of a wedge.Notes 1.A frequent cause of interdental papillae protruding from beneath the rubber dam is holes that were punched too close together. 2. Wrinkling of the rubber dam between isolated teeth is the result of holes that were punched too far apart.

rubber damThe Young rubber dam frame is used more than the Woodbury version,because it provides less soft tissue retraction.• Both the statement and the reason are correct and related• Both the statement and the reason are correct but not related• The statement is correct, but the reason is not• The statement is not correct, but the reason is correct• Neither the statement nor the reason is correct 102 copyright © 2016-2017 Dental DecksOPERATIVE

• Both the statement and the reason are correct but not related*** It is true that the Young rubber dam frame provides less soft tissue retraction than theWoodbury. However, that is not why it is used - it is simply more convenient.Important points about using the rubber dam: • Apply lubricant to the lips and corners of the patient’s mouth. • Plot the hole on the rubber dam. Always isolate a minimum of three teeth. Punch the appropriate size hole for a particular tooth. For a tooth bearing a clamp, the hole should be one size larger than those without a clamp. • An appropriate clamp is selected that will fit the most distal tooth to be isolated. The dam may either be stretched over the clamp with the clamp in place on the tooth, or the clamp may be carried with the dam and placed on the tooth in one step. • Once the dam is placed, it is secured with either a Woodbury or Young holder (frame). • The rubber dam is inverted into the gingival sulcus using floss and/or a blast of air and an instrument such as a plastic instrument — this will prevent seepage of saliva.Removal of the rubber dam — very important: Removal is the reverse of application,except all ligatures (interdental septum of dam) must be cut and removed before thedam is removed.

sealants/fluoridePut the following steps in order for proper sealant placement.• Apply acid etch• Place the low viscosity sealant material• Apply bonding agent• Wash acid etch away• Use rubber prophy cup with pumice 103 copyright © 2016-2017 Dental DecksOPERATIVE

• Use rubber prophy cup with pumice • Apply acid etch • Wash acid etch away • Apply bonding agent • Place the low viscosity sealant materialImportant: Sealants need micromechanical retention. The surfaces should be cleaned with aprophylaxis brush or rubber cup and pumice with water. When the teeth are effectively isolated fromsaliva contamination, the surfaces are dried and acid-etched by the application of a 30% to 50%phosphoric acid solution for 1 minute. The solution should be gently agitated during the application.This is then washed away and dried, leaving a frosty-appearing (dull and chalky) etched surface.Miscellaneous information concerning sealants: 1. The placement of sealants is a highly effective means of preventing pit and fissure caries. It is safe. It is currently underused in both private and public dental health care delivery systems. 2. The substantial reductions in dental decay that have occurred in the young population of the United States are due, for the most part, to the use of systemic and topical fluorides. The control of smooth surface caries that is provided by fluorides is of critical importance to the additional effectiveness of sealants. 3. The properties of sealants are closer to those of unfilled direct resins than to those of filled resins (composites). 4. Sealants are weak compared to filled resins (composites). The strength of a sealant is sacrificed into make it flow into the pits and fissures (the viscosity needs to be low enough to flow into the pits and fissures). 5. The most likely result of inadvertently sealing a small carious lesion in the occlusal surface of a tooth is that the caries would be arrested. 6. Research indicates that pit and fissure sealants are retained best on maxillary and mandibular bicuspids. However, the first molars (max. and mand.) benefit the most from sealants. 7. If a topical fluoride is to be used in conjunction with a pit and fissure sealant, the fluoride must be applied either before the conditioner (acid etchant) or after the sealant.

sealants/fluorideThe light cured sealants require UV light.The light cured sealant types are shown to be clinically better than chemicalcured sealants.• Both statements are true• Both statements are false• The first statement is true, the second is false• The first statement is false, the second is true 104 copyright © 2016-2017 Dental DecksOPERATIVE

• Both statements are falseRemember: Light cured materials are all cured by visible light nowadays, not UV. Also, both lightcured and chemical cured sealants have indistinguishable results.Pit and fissure sealants were first developed in the 1970s and 1980s, and their effectiveness in pre-venting caries has now been well established. Two predominant types of pit and fissure sealant ma-terials are available: resin-based sealants and glass ionomer cements.Available resin-based sealant materials can be polymerized by autopolymerization, photopoly-merization using visible light, or a combination of the two processes.Glass ionomer cements are available in two forms, both of which contain fluoride: conventionaland resin-modified. Glass ionomer cements, which do not require acid etching of the tooth surface,generally are easier to place than are resin-based sealants. They also are not as moisture-sensitiveas their resin-based counterparts. Glass ionomer materials, which were developed for their abilityto release fluoride, can bond directly with enamel. It is hypothesized that release of fluoride fromthis material may contribute to caries prevention. However, the clinical effect of fluoride releasefrom glass ionomer cement is not well established.Notes 1. The success of a sealant is highly dependent on obtaining and maintaining an intimate adaptation of the sealant to the tooth surface and thereby, hopefully, sealing it. 2. Research has demonstrated that caries protection is 100% in pits and fissures that remain completely sealed. 3. Resin-based sealants are the first choice of material for dental sealants. 4. Glass ionomer cement may be used as an interim preventive agent when there are indications for placement of a resin-based sealant but concerns about moisture control may compromise such placement. 5.Placement of pit and fissure sealants significantly reduces the percentage of noncavi- tated carious lesions that progress in children, adolescents, and young adults for as long as 5 years after sealant placement, compared with unsealed teeth.

sealants/fluorideRegarding the benefits of fluoride, all of the following are true EXCEPT one.Which one is the EXCEPTION?• Fluoride increase the hardness of the enamel• Fluoride reduces the rate of enamel solubility• Fluoride ions have greater affinity for hydroxyapatite than hydroxyl ions• Fluoride inhibits bacterial intracellular polysaccharide formation 105 copyright © 2016-2017 Dental DecksOPERATIVE

• Fluoride increase the hardness of the enamel*** Fluoride does not make the enamel harder but reduces its rate of solubility.Fluorides exert their anticaries effect by three different mechanisms: 1. The presence of fluoride ions greatly enhances the precipitation into tooth structure of fluorapatite from calcium and phosphate ions present in saliva. This insoluble precipitate replaces the soluble salts containing manganese and carbonate, which were lost due to bacterial-mediated demineralization. This exchange process results in the enamel becoming more acid resistant. 2. Incipient, noncavitated, carious lesions are remineralized by the same process. 3. Fluoride has antimicrobial activity. In low concentrations, fluoride ion inhibits the enzymatic production of glucosyltransferases (e.g., dextransucrase). This prevents glucocyltransferases from using glucose to form insoluble glucans (e.g., dextrans, mutans, and levans). This also reduces bacterial adhesion and slows ecological succession. Intracellular polysaccharide formation is also inhibited, preventing storage of carbohydrates by limiting microbial metabolism between the host’s meals. Thus, the duration of caries attack is limited to periods during and immediately after eating.Notes 1. The concentration of fluoride in the body fluids is regulated by an equilibrium relationship between bone and urinary excretion. 2. Fluoride ion is easily exchanged for hydroxyl ion in the lattice structure of enamel because the fluoride ion is slightly smaller than the hydroxyl ion, and it has a greater affinity for the hydroxyapatite crystal than does the hydroxyl ion.

sealants/fluorideThe average cost for a community to fluoridate its water is estimated to rangefrom approximately $0.50 a year per person in large communities to approxi-mately $3.00 a year per person in small communities. For most cities, every $1invested in water fluoridation saves _____ in dental treatment costs.• $10• $25• $38• $58 106 copyright © 2016-2017 Dental DecksOPERATIVE

• $38In relation to teeth, fluoride is characterized by the following: • Its concentration increases in the external layer of enamel throughout life • Its concentration increases during topical application but decreases for a few days after treatment • Fluoride uptake is greater in enamel than in dentin or cementum • Increasing the fluoride content in the external layers of the tooth increases the resistance of the enamel to demineralizationRemember: The optimal concentration of fluoride in community drinking water dependson the average air temperature and the average water consumption. For temperate cli-mates, it is 1 ppm, and for warmer and colder climates, the amount can be adjusted from0.7 to 1.2 ppm, respectively.Notes 1. In communities without fluoridated water supplies, the most cost-effective method of delivering fluoride to 6- to 12-year-old children is through school water fluoridation (as opposed to fluoride tablets, brushing with a fluoride gel, or rinsing with fluoride mouth rinse). 2. The most effective means of increasing the fluoride content in the external layers of teeth is the daily application of 1.23% acidulated phosphate fluoride in fitted trays for 4 minutes. Obviously, this is not realistic since we do not routinely do “daily” applications.

sealants/fluorideAll persons should know whether the fluoride concentration in their primarysource of drinking water is below optimal (____________), optimal(______________), or above optimal (______________).• less than 0.5 ppm, 0.5–1.0 ppm, greater than 1.0 ppm• less than 0.7 ppm, 0.7–1.2 ppm, greater than 1.2 ppm• less than 0.8 ppm, 0.8–1.3 ppm, greater than 1.3 ppm• less than 0.9 ppm, 0.9–1.4 ppm, greater than 1.4 ppm 107 copyright © 2016-2017 Dental DecksOPERATIVE

• less than 0.7 ppm, 0.7–1.2 ppm, greater than 1.2 ppmThe optimal fluoride levels for public water supplies is about 1 part per million (PPM).At 0.1 PPM and below, the preventive effect is lost, and the caries rate is higher for suchpopulations lacking sufficient fluoride exposure.This knowledge is the basis for all individual and professional decisions regarding use ofother fluoride modalities (e.g., fluoride toothpaste for children under 2 years of age, mouthrinse, or supplements). It is recommended that parents and caregivers of children,especially children aged less than 6 years, know the fluoride concentration in their child'sdrinking water. For example, in nonfluoridated areas where the natural fluoride concen-tration is below optimal, fluoride supplements might be considered, whereas in areaswhere the natural fluoride concentration is more than 2 ppm, children should usealternative sources of drinking water.Fluoride is obtained in two forms: topical and systemic. Topical fluorides are found inmany types of toothpaste, mouth rinses, and special gels or pastes applied in the dentaloffice.Systemic fluorides are those that are ingested. They include fluoridated water and dietaryfluoride supplements in the form of tablets, drops, or lozenges. Systemic fluorides areintegrated into children's teeth as their tooth structures form.The greatest reduction in tooth decay is achieved when fluoride is available bothtopically and systemically. Water fluoridation provides both types of contact.

sealants/fluorideStudies have established that root sensitivity is due, in part, to open dentinaltubules at the root surface.The hydrodynamic theory is the proposed mechanism for this sensitivity.• Both statements are true• Both statements are false• The first statement is true, the second is false• The first statement is false, the second is true 108 copyright © 2016-2017 Dental DecksOPERATIVE

• Both statements are trueThe most accepted theory to explain the unusual sensitivity and response of exposedroot surfaces to various stimuli is the hydrodynamic theory. This theory postulates thatthe pain results from indirect innervation caused by dentinal fluid movement in thetubules, which stimulates mechanoreceptors near the predentin.The rationale of desensitization procedures is not fully understood. Some techniques maydepend on denaturation of the superficial ends of Tomes fibers or of nerve endings indentin. Other procedures are designed to deposit an insoluble substance on the ends of thefibers or nerves to act as a barrier to stimuli. Still others are designed to stimulatesecondary dentin formation, thus insulating the pulp from external stimuli.Numerous forms of treatment have been used to provide relief, such as topical fluoride,fluoride rinses, oxalate solutions, dentin bonding agents, sealants, iontophoresis, anddesensitizing toothpastes. All of these methods have met with varying degrees of success,and none has been totally effective (although dentin bonding agents provide the best rateof success). When these conservative methods fail to provide relief, restorative treatmentis indicated.Note: The application of sodium fluoride has been recommended as an effectivetreatment for root sensitivity based on the precipitation of calcium fluoride crystals in theopen dentinal tubules.

sealants/fluorideWhich of the following types and concentrations of fluoride should berecommended for home-care custom tray use by a patient with head and neckcancer?• 1.23% acidulated phosphate fluoride and 1% neutral sodium fluoride• 0.4% stannous fluoride and 1.23% acidulated phosphate fluoride• 0.4% stannous fluoride and 1% neutral sodium fluoride• 1.23% acidulated phosphate fluoride, 0.4% stannous fluoride, and 1% neutral sodium fluoride 109 copyright © 2016-2017 Dental DecksOPERATIVE

• 0.4% stannous fluoride and 1% neutral sodium fluorideThe gel contains either 1.0% sodium fluoride or 0.4% stannous fluoride. Formaximum benefit, the gel must be in direct contact with the teeth. Fluorides arerecommended to protect these patients from postirradiation caries.Remember two important points: 1. The fluoride found in commercial toothpastes is not adequate for people who have undergone treatment with head and neck radiation. 2. These patients must continue to use the fluoride gel as directed for the rest of their lives to protect their teeth from rampant decay.Instructions for patient: The trays containing the fluoride are placed over the teeth fora prescribed time (usually 10 minutes), and he/she may not eat or drink for at least 30minutes. Usually this is done at night after toothbrushing and just before going to bed.The daily use of fluoride gel in custom trays at home is indicated in the followingsituations: • Rampant enamel or root caries in any age group • Xerostomia • Head and neck radiation therapy • For use on abutment teeth under an overdenture • Hypersensitive root surfacesImportant: Fluorapatite is the most stable reaction product of a topical application offluoride.

sealants/fluorideMatch the following fluoride application options with their respective key point.Acidulated phosphate fluoride (APF) Causes the most severe stainingStannous fluoride (SNF2) Most common over-the-counter fluorideSodium fluoride (NaF) Most common in-office fluoride 110 copyright © 2016-2017 Dental DecksOPERATIVE

• Acidulated phosphate fluoride (APF) — Most common in-office fluoride• Stannous fluoride (SNF2) — Causes the most severe staining• Sodium fluoride (NaF) — Most common over-the-counter fluorideImportant: 1. Acidulated phosphate fluoride (APF) is the most commonly applied in-office fluoride treatment. 2. The combination of 1.23% sodium fluoride and 1 M orthophosphoric acid results in acidulated phosphate fluoride. It is very stable in solution. 3. The most common recommended over-the-counter fluoride is 0.05% sodium fluoride. 4. Stannous fluoride (8% F) has a very bitter, metallic taste, may burn the mucosa, and has a short shelf life. 5. The tin ion in stannous fluoride may be responsible for staining the teeth, but it may be beneficial for arresting root caries. Fluoride Agents for Professional Application NaF APF SnF2Concentration 2% 1.23% 8%`Fluoride ion % 0.91 1.23 1.95ppm Fluoride 9,040 ppm 12,300 ppm 19,360 ppmMg Fl/ml 9.04 12.0 19.36Efficacy 29% 28% 32%Taste Bland Bitter w/o flavoring Very bitter, metallicTooth discoloration None None BrownGingival reaction None None Occasional

sealants/fluorideThe pH of acidulated phosphate flouride is approximately:• 1.0• 3.5• 7.0• 9.2 111 copyright © 2016-2017 Dental DecksOPERATIVE

• 3.5Important: • The pH of APF is approximately 3.5 (acidic) • The pH of NaF is approximately 9.2 (basic) • The pH of SnF2 is approximately 2.1 to 2.3 (acidic)Important: APF solutions and stannous fluoride (SNF2) should not be used on patients withporcelain, glass ionomer, and composite restorations. They have been shown to remove theglaze from the surface of these restorations. Neutral sodium fluoride (NaF) is best to use ifthese restorations are present. Also, APF should be avoided on implant patients, it may cor-rode the surface of titanium implants.When painting fluoride on, it is very important to isolate the teeth with cotton rolls. Whenusing fluoride trays, cotton rolls may be placed in the premolar areas to increase patient com-fort and help keep the fluoride in place. Patients are asked not to brush, rinse, eat, or drink 30minutes after a fluoride treatment so that the fluoride is left undisturbed and is able to continuereacting with the hydroxyapatite for some time after the initial application. Fluoride treat-ments should be applied for 4 minutes, although there are now some 1-minute products thatare being marketed.

sealants/fluorideA 40kg child gets into the bathroom cabinet and eats one tube of toothpaste con-taining 230mg of fluoride. The mother calls you first before calling poison con-trol asking whether her son would be OK. You tell the parent the toxic amountof fluoride based on the child's body weight is:• 160 mg• 200 mg• 240 mg• 280 mg 112 copyright © 2016-2017 Dental DecksOPERATIVE