Dr. Emad Farhan Alkhalidi Introduction to Operative Dentistry Dr. Emad Farhan Alkhalidi

DEFINITION Operative dentistry is the art and science dealing with the restorations of any fault “Defect” that occurs in the hard tooth structures. It necessitates the formation of Cavities of specific design and form to receive the filling “restorative material” of choice

SCOPE Operative dentistry consists of all procedures including preventive measures by which teeth may be conserved and thus maintain the natural masticating mechanism in such a state that the general health will not be endangered

Goal of Dental Sciences • Elimination of disease and restoration of oral health, form and function.

The placement of a restoration in a tooth requires the dentist to: • Practice applied human biology + microbiology • Possess highly developed technical skills • Demonstrate artistic abilities

THE DEFINITION OF OPERATIVE DENTISTRY includes the following: Defects which affect the teeth Restoration

OBJECTIVE OF OPERATIVE DENTISTRY Operative dentistry has five fundamental aims Diagnosis Prevention Interception Preservation Restoration

Proper diagnosis of lesions including their * location * extent Correct treatment planning including * the design of tooth preparation * the selection of restorative materials and procedure

PREVENTION The ultimate aim regarding dental caries is its prevention, therefore, every step of an operative procedure must emphasize this. For example, * Location of the margins * The shape (contour) of the final restoration * Sealing of enamel faults- pits and fissures Prevents any recurrence of decay and their defects

INTERCEPTION This procedure in operative dentistry refers to preventing further loss of tooth structure by stabilizing an active disease process.

PRESERVATION This includes * The vitality of the affected tooth * Re establishing of the important anatomy in remaining sound tooth structure

RESTORATION The ultimate goal of operative dentistry treatment should be restoration of health. This will include Restoring and maintaining form, function, phonetics and esthetics Occlusal re establishment and stability Not only to the teeth themselves, but also to their surrounding supporting tissues and to the entire stomatognathic system and to the welfare of the whole patient.

To achieve the ultimate goals of operative dentistry, any restorative performance requires Sound clinical judgment in both mechanical and biological aspects based on scientific and artistic knowledge A high level of psychomotor skill “Precision”. Operative dentistry demands a unique combination of psychomotor and affective skills.

DEFECTS WHICH AFFECT THE TEETH l. Pathologic: Dental caries

DENTAL CARIES DEFINITION “ It is a disease of the calcified tissues of the teeth, characterized by a demineralization of the inorganic portion and destruction of the organic substance of the tooth”

CAVITY The term cavity refers to a defect in enamel, or in enamel and dentin, usually resulting from the pathologic process of dental caries.

Prepared cavities The performance of those dental surgical procedures required to expose the carious lesion, permit removal of affected tissues, and to shape the remaining dentin and enamel as to contribute to biologically and mechanically sound restoration.

II. Developmental structural defects Enamel Hypoplasia: Acquired condition Causes: Infectiuos disease in childhood ”fever” Trauma Abscess to developing crown

III. Hereditary Amelogenesis imperfecta: Hereditary abnormality Insufficient amount of enamel, soft enamel, friable and easy lost

III. Hereditary Dentinogenesis imperfecta: hereditary condition Teeth appear yellow-brown to gray Enamel is fractured easily due to poor support provided by the abnormal dentin

* Peg-shaped lateral incisor * Hutchinson’s incisor * Mulberry molars III. Hereditary * Peg-shaped lateral incisor * Hutchinson’s incisor * Mulberry molars Seen with congenital syphilis

IV. Nutritional * Enamel hypocalcification: incomplete calcification or Hardening of enamel (hypomineralized)

V. Formative * Dens invaginatus and dens evaginatus or tooth within a tooth exaggeration or accentuation of the lingual pit. The cause is unknown

VI. Acquired tooth wear A. Attrition – Mechanical wear between opposing teeth • Causative agent abrasive diet , bruxism, (clenching and grinding, age) • Affected area occlusal or incisal surface

B. Abrasion –Wearing away of tooth substance by mechanical means other than by opposing teeth: • Causative agent over vigorous tooth brushing., biting pen or hard object, pipe smoking • Affected area buccally at cervical margin. Dish-shaped or V-shaped

C. Erosion: – Loss of dental hard tissue as a result of a chemical process not involving bacteria. • Causative agent ⇒ acid • Source of acid ⇒ dietary (citrus fruits, acid containing drinks) , stomach • Affected area ⇒ palatal surface ant., facial surface.

Treatment of Defects which affect the teeth RESTORATION: Is an artificial substitute which replace the missing portion of the hard tooth tissues. Restorations must not only retain the tooth to its normal form, function, strength, and esthetic, but they must also provide for the health of the supporting tissues. Faulty restorations are a common etiological factor of periodontal disease. An unfavorable response of the periodontium will result in occlusal disharmonies. If not corrected, thus causing traumatic occlusion.

RESTORATIVE MATERIALS The replacement of lost hard tooth structure cannot be achieved without using the proper restorative dental materials. This include: Temporary restorative materials Permanent restorative materials

Metal Polymers Ceramics PERMANENT RESTORATIVE MATERIALS INCLUDE Composite resin Glass-ionomer- cements Acrylic Ceramics porcelain Amalgam Gold Noble metal Cobalt-chromium- alloys Nickel-chromium- alloys

PERMANENT RESTORATIVE MATERIALS Direct restorative materials * Esthetic restorative materials (composite resin, Glass- ionomer and compomer) * Metalic restoration (amalgam, gold foil) Indirect restorative materials * Cast gold restoration * Castable ceramic restoration