General Dentistry Chapter 48 1 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 1

Chapter 48 Lesson 48.1 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 2

Learning Objectives Define, spell, and pronounce the Key Terms. Describe the process and principles of cavity preparation. Discuss the differences between assisting with an amalgam and with a composite restoration. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 3

Introduction Restorative and aesthetic dentistry is focused on the general dental needs of the patient. Restorative dentistry is also called operative dentistry. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 4

Restorative Dentistry Specific conditions that initiate a need for restorative dental treatment are: Initial or recurring decay. Replacement of failed restorations. Abrasion or the wearing away of tooth structure. Erosion of tooth structure. What type of materials would be used for restorative dentistry? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 5

Esthetic Dentistry Specific conditions requiring aesthetic dental treatment: Discoloration due to extrinsic or intrinsic staining Anomalies due to developmental disturbances Abnormal spacing between teeth Trauma What type of materials are used for aesthetic dentistry? Why are aesthetics important? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 6

Terminology in Cavity Preparation Understanding the terminology will help dental assistants prepare the correct instruments for a procedure. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 7

Initial Cavity Preparation Outline form Design and initial depth of sound tooth structure Resistance form Shape and placement of cavity walls Retention form To resist displacement or removal Convenience form Provides accessibility in preparing and restoring the tooth Initial cavity preparation is the first of two stages of cavity preparation and has a set number of steps that the dentist follows in an exact order. This process is performed to gain access to the decay or defect. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 8

Final Cavity Preparation Removal of decayed dentin or old restorative material Insertion of resistance and retention with the use of hand cutting instruments and burs. Placement of protective materials (liners, bases, desensitizing, or bonding) Final cavity preparation is the second stage of cavity preparation. This procedure is followed after the steps in the initial cavity preparation have been completed. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 9

Patient Preparation for Restorative Procedures Inform the patient what to expect throughout the procedure. Position the patient correctly for the dentist and the type of procedure. Explain each step to the patient as the procedure progresses. What is the correct position of a patient during the procedure? How would the dental assistant explain the procedure to the patient? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 10

Responsibilities of the Chairside Assistant Prepare the setup for the procedures. Know and anticipate the dentist’s needs. Provide moisture control. Transfer dental instruments and accessories. Mix and transfer dental materials. Maintain patient comfort. What are the appropriate setup items needed for an amalgam restoration? What are the appropriate setup items needed for a composite restoration? How can the dental assistant provide moisture control? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 11

Steps in the Restorative Procedure The dentist evaluates the tooth to be restored. The dentist administers local anesthesia. The assistant readies the chosen means of moisture control. The dentist prepares the tooth. The dentist determines the type of dental materials. The assistant mixes and transfers the dental materials. The dentist burnishes, carves, or finishes the dental material. The dentist checks the occlusion of the restoration. The dentist finishes and polishes the restoration. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 12

Class I Restorations These restorations are used in class I lesions, affecting the pits and fissures of the teeth. The following surfaces are involved: Occlusal pits and fissures of premolars and molars Buccal pits and fissures of mandibular molars Lingual pits and fissures of the maxillary molars Lingual pits of maxillary incisors, most frequently in the pit near the cingulum Why are class I restorations so common? What are pits and fissures? Where are they located? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 13

Fig. 48-5 Class I restorations. Which anterior teeth would have class I restorations? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 14

Class II Restorations A class II lesion is the extension of a class I lesion into the proximal surfaces of premolars and molars. The following surfaces are involved: Two-surface restoration of posterior teeth Three-surface restoration of posterior teeth Four-surface (or more) restoration of posterior teeth What accessory items would be needed for a class II restoration? (Matrix system.) Why would this be needed? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 15

Fig. 48-7 Class II restorations Fig. 48-7 Class II restorations. (From Baum L, et al: Textbook of operative dentistry, ed 3, Philadelphia, 1995, Saunders.) Which teeth are involved in this example? Which surfaces are involved in this example? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 16

Class III and IV Restorations Class III lesion Affects the interproximal surface of incisors and canines Class IV lesion Involves a larger surface area, including the incisal edges and interproximal surface of incisors and canines What accessory items would be needed for class III and class IV restorations? (Mylar-strip matrix system.) Why is this needed? Can a metal matrix system be used? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 17

Fig. 48-9 Class III composite restoration. Which teeth are involved in this example? What surfaces are involved in this example? Why would a dental dam be needed in this procedure? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 18

Fig. 48-10 Class IV composite restoration. How does a Class IV restoration differ from a Class III restoration? Why would a dental dam be used? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 19

Class V Restorations Class V restoration Decayed lesions occur at: Classified as a smooth-surface restoration. Decayed lesions occur at: Gingival third of the facial or lingual surfaces of any tooth Root of a tooth, near the cementoenamel junction Class V lesions tend to occur in older patients. Why are older people more susceptible to this type of decay? What material is generally used for this type of restoration? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 20

Fig. 48-13 A, Class V conventional tooth preparation Fig. 48-13 A, Class V conventional tooth preparation. B, Schematic representation illustrating tooth preparation. (From Roberson T, et al: Textbook of operative dentistry, ed 4, Philadelphia, 2006, Elsevier.) What could be used to help reflect the tissue away from the preparation? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 21

Chapter 48 Lesson 48.2 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 22

Learning Objectives Discuss why retention pins would be selected for a complex restorative procedure. Describe the need for placement of an intermediate restoration. Describe the procedure of composite veneers. Describe tooth-whitening procedures and the role of the dental assistant. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 23

Complex Restorations Such restorations are required when decay has extended beyond the normal size or shape. Retention pins Decay has extended into the cusp of a tooth and undermined the enamel and dentin. General understanding when using retention pins: One pin is placed for each missing cusp. Retention pins are commonly used in a tooth for retaining and supporting a restoration. Multiple pins may be placed in one tooth. Pins are available in different widths and are supplied in a kit. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 24

Fig. 48-14 Retention (retentive) pins placed in tooth structure to help retain and support a restoration. A “drill” is used to place the pin in a prepared tooth. No cementation of the pin is required. The extended portion of the retention pin is open to adhere to the restorative material that is to be placed. Why is it important to use a dental dam when preparing and placing pins? (Because the pins are so small, they are easily dropped or misplaced.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 25

Intermediate Restorations Restoration placed for a short term. Primary factors for placement Health of the tooth A wait to receive a permanent restoration Financial reasons Intermediate restorations are not meant to be permanent. An intermediate restoration is a preliminary step before a final restoration is placed. Why has this procedure been approved as an expanded function of the dental assistant? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 26

Procedure 48-5 Placement of intermediate restorative material. What is the appropriate consistency of the intermediate restorative material? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 27

Direct Bonded Veneers Veneer Thin layer of tooth-colored material, applied to the facial surface of a prepared tooth Used to improve the appearance of teeth that are: Abraded Eroded Discolored with intrinsic stains Darkened after endodontic treatment Direct veneers are not fabricated by the dental laboratory technician. Direct veneers are made of a resin composite material. What are some examples of intrinsic stains? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 28

Fig. 48-15 Veneers placed to reduce discoloration and cover stain Fig. 48-15 Veneers placed to reduce discoloration and cover stain. (From Roberson T, et al: Sturdevant’s art and science of operative dentistry, ed 4, St Louis, 2002, Mosby.) Which teeth may have been involved in this procedure? Are posterior teeth fitted with veneers? Why or why not? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 29

Fig. 48-16 Veneers placed to close diastema Fig. 48-16 Veneers placed to close diastema. (From Roberson T, et al: Sturdevant’s art and science of operative dentistry, ed 4, St Louis, 2002, Mosby.) What is a diastema? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 30

Tooth Whitening Known as vital bleaching, tooth whitening is a noninvasive method of lightening dark or discolored teeth. How many students know of someone who is currently using a bleaching system? What does the term “vital” mean? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 31

Indications for Using a Tooth Whitener Indications for Procedure Extrinsic stains from foods, cigarette smoking, coffee, or tea Aged, discolored teeth Intrinsic stains, such as mild tetracycline stains and mild fluorosis Patients should be advised that bleaching is neither guaranteed nor permanent. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 32

Fig. 48-17 Before-and-after photos of tooth whitening used for extrinsic stains. How long do the effects of most whitening systems last? (Between 3 and 5 years.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 33

Fig. 48-18 Before-and-after photos of tooth whitening used for intrinsic stains. (From Roberson T, et al: Sturdevant’s art and science of operative dentistry, ed 4, St Louis, 2002, Mosby.) What causes intrinsic stains? Intrinsic stains are harder to bleach. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 34

Whitening Products Chemical makeup Active ingredient Gel base Either carbamide peroxide or hydrogen peroxide Gel base With one or a mixture of propylene glycol, glycerin, and water Thickener Carbopol Whitening product is only applied to the facial surface of the tooth. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 35

At-Home Tooth-Whitening Procedure Material is placed in a thermoplastic custom tray that the patient wears for a designated period. With the 10% to 16% carbamide peroxide gels, the wear schedule is 1 hour twice a day for the first week and once a day for the second week. The 20% to 22% mixture is used for 1 hour a day for 2 weeks. Hydrogen peroxide is used for 15 to 30 minutes, two or three times a day, for 2 weeks. What type of impression is taken? What symptoms would a patient who wore the bleach tray longer than recommended experience? Many patients do not see the effects of bleaching if they do the maxillary and mandibular arches at the same time. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 36

Tooth-Whitening Strips Thin, flexible strips are coated with an adhesive hydrogen peroxide whitening gel. Application The patient peels off the backing like a Band-Aid and presses the strip to the facial anterior teeth. The remaining portion of the strip is folded onto the lingual surface. Extra-strength whitening strips are dispensed by dental offices only. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 37

Possible Complications to Tooth Whitening Thermal hypersensitivity Patient may experience sensitivity to heat and cold after removal of the tray and material. The use of toothpaste for sensitive teeth is recommended. Tissue irritation Gingival tissue exposed to excess gel as a result of improper tray fit may become irritated. Tell the patient not to overfill the tray with material and to remove any excess after seating the tray. Why do patients undergoing tooth whitening need to schedule follow-up dental appointments? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 38

Dental Assistant’s Role in Tooth-Whitening Procedure Aid in recording the medical and dental history. Assist in making shade selection. Take intraoral photographs before and after whitening. Take and pour up preliminary impressions for the tray. Fabricate and trim the tray. Provide postoperative instructions. Assist in weekly or biweekly clinical visits. What is the purpose of taking a preshade? Why are photographs taken before and after the tooth-whitening process? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 39

Patient Instructions for Tooth-Whitening Procedure Brush and floss before tray placement. Place equal amounts of gel in tray. Seat tray. Do not eat or drink when wearing the tray. Wear tray for the recommended time. If the patient experiences any problems, discontinue use and discuss with the dentist. Why shouldn’t patients eat or drink while wearing the bleaching trays? What sort of problems may a patient experience during tooth whitening? Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 40