Dental Restorations: Selection Guide PDF

Selection Of Suitable Restorative Material Dental restoration: Material used to restore the function, integrity and morphology of missing or damaged tooth structure. Requirements for an ideal restoration: 1. It should stop further progress of the present lesion such as caries, erosion, abrasion, a...

Selection Of Suitable Restorative Material Dental restoration: Material used to restore the function, integrity and morphology of missing or damaged tooth structure. Requirements for an ideal restoration: 1. It should stop further progress of the present lesion such as caries, erosion, abrasion, attrition or fracture. 2. It should restore normal function of the affected tooth which may be cutting, tearing or mastication of food. 3. It should restore any speech defects due to missing parts of the hard tooth structures. 4. It should restore normal esthetic. 5. It should restore and maintain the integrity of the dental arch and its surrounding periodontium. 6. It should sustain the normal physiologic occlusal load without fracture, and it should protect the remaining hard sound tooth structures from fracture. 7. It should protect and maintain pulp vitality. 8. It should maintain a constant relationship with the surrounding hard tooth structures. Factors influencing selection of the suitable restorative material: I. Factors concerning the available restorative materials. II. Factors concerning the patient. III. Factors related to the operator. 1 I) Factors concerning the available restorative materials: Assessment of mostly used permanent restorations properties: Biocompatibility, physical properties, aesthetics and application A- Biocompatibility: - Refers to how well the material coexists with the biological equilibrium of the tooth and body systems. - Since fillings are in close contact with mucosa, tooth, and pulp, biocompatibility is very important. a- Metallic restoration can conduct thermal shocks to the pulp due to its high thermal conductivity which could lead to pulp irritation: Gold foil cause thermal and/or traumatic irritation to the pulp Amalgam restorations conduct thermal and galvanic shocks to the pulp and its metallic ions may penetrate the dentinal tubules and gingival tissues. Amalgam courses permanent discoloration of both tooth and gingiva will be the expected failures after restoration of large cavity with amalgam b- Resin composite: It’s volumetric contraction and the relatively high-coefficient of thermal expansion can create leakage space at the restoration-tooth structure interface and stimulate bacterial irritation for the pulp. Resin composite monomer contents and the heat produced during polymerization that lead to both chemical and thermal irritation to the pulp On the other hand, tooth preparation of resin composite restorations requires less tooth structure removal compared to preparation for other dental materials such as amalgam c- Glass ionomer restorations: The best regarding biologic compatibility. This can be attributed to their chemical bond with the adjacent tooth structures, to their high molecular size of its acid contents, fluoride release and recharge, minimal setting expansion. d- Castable ceramic restorations are biologically compatible due to their thermal insulation and their highly smooth glazed surfaces. However, resin cement used for its lutting may cause pulp irritation. - Most of the previously mentioned irritational factors can be controlled by using suitable cavity liner and/or base material. These materials can protect the pulp from both chemical and thermal irritation of the restorations 2 B- Physical properties: 1. Indestructible and/or insoluble in the oral fluids: - Metallic, ceramic and resinous restorative materials can resist solubility in oral fluids. While, glass ionomer restorations cannot resist solubility, so they are intermediate restorations. - Luting cements such as zinc phosphate or zinc polycarboxylate cements are relatively soluble in the oral fluids particularly in acidic media. 2. Chemical adhesion with the surrounding hard tooth tissues: - It should maintain intimate adaptation with the surrounding cavity walls at the restoration – tooth structure interface. - The importance of adhesion or adaptation is to provide marginal sealing to prevent microleakage. Thus, post restorative hypersensitivity of dentin, recurrent caries, pulp affections and discoloration of both restorations and tooth structures will be prevented. - Adaptation of amalgam restorations increase by time due to the presence of the corrosion products. - Resin composite restorations do not adhere or adapt to the cavity walls due to their hydrophobic nature, their polymerization shrinkage and their different coefficient of thermal expansions. Thus, they usually needed proper adhesive systems of high bond strength to both enamel and dentin to produce successful sealed restorations. - Glass ionomer restoration is the only restorative material that has a self-adhesive potential and bond chemically with the surrounding tooth structures. - Casted restorations suffer from marginal deterioration due to the solubility or wear of their luting cements. 3. Withstand the functional forces without fracture: - It should protect the surrounding hard tooth structures from fracture. Moreover, it should have high surface hardness to retain its smooth shiny surface condition. Ceramic and gold restorations fulfill this property. - Amalgam restorations suffer from low tensile and shear strength (brittle) and creep. - Glass ionomer restorations cannot resist wear. - Resin composite restorations suffer from decreased wear resistance compared to the amalgam; however, recent types had an increased in its wear resistance given the restorations an average lifespan 7-8 years. 3 4. Maintain its dimensional stability inside the cavity: - The restoration should be free from any volumetric changes after its placement inside the cavity. - If it expands, it may overhang producing premature contact, which may fracture due to stress concentration. - It may exert pressure on dentin and create discomfort for the patient and may lead to pulp hyperemia or pulpitis - On the other hand, contraction or shrinkage of the restoration inside its cavity may cause marginal leakage with subsequent troubles or it may lead to its looseness and displacement. - Ceramic and gold restorations are stable inside their cavities. - Amalgam restorations may contract inside their cavities during their hardening, and they may expand due to either excess mercury or moisture contamination. - Dental composite restorations shrink during their polymerization. - Glass ionomer restorations have less dimensional changes compared to the other restorations and they do not create marginal leakage due to their chemical bond with the adjacent tooth tissues. C- Aesthetic properties: The selected restoration esthetic’s properties should be very close to the combined esthetic properties of both enamel and dentin. Porcelain restorations can provide perfect esthetic with that of the natural tooth. Resin composite restorations provide superior esthetic. However, by time, some resin composites restorations suffer from surface, marginal and bulk discolorations. The rate of discoloration is changeable from a person to the other according to the type of material, technique of application and patient habits i.e. drinks and smoking habits. Although Glass-ionomers are tooth-colored, their aesthetic potential does not measure up to that provided by resin composite because their surfaces change to the chalky appearance as a result of their solubility in the oral fluids. D- Other material properties: 1. It should have reasonable cost: The restoration should be inexpensive either in its price or in its techniques for production or manipulation. Amalgam is relatively cheaper than gold as a metallic restoration. Porcelain restoration is the most expensive tooth-colored one. Glass ionomer restoration needs cost similar or near to that of composite ones. 4 2. It should be convenient and easy in its manipulation: The restorative material should not be sensitive to the human variables of the operator. It should be produced easily without detailed procedures or expensive special equipment. Amalgam restorations satisfy this property. Gold foil restorative procedures need skillful operator. Resin composite is a technique sensitive material needs complete isolation, and skillful manipulation. Glass ionomer restorations are easy in their manipulation by the average operator. II) Factors related to the patient: A- Factors related to the general condition of the patient: a. Patient’s age: 1. Young patient cannot stand long dental chair-side work. They cannot follow post-restorative instructions carefully. They prefer esthetic restorations wherever indicated. 2. Middle aged patient prefers ideal restorations. 3. Old patient cannot withstand long operations on the dental chair. He prefers strong permanent restorations. b. Patient’s sex: 1. Male patients prefer strong permanent restorations. 2. Female patients advocate esthetic. 5 c. Patient’s occupation: 1. Regular patients ask for restorations of reasonable price. They prefer ideal restoration if possible. 2. Public personalities like esthetic restorations. Those are; politicians, professors and teachers, spokesmen, television and movie stars. 3. Few technicians, butchers, fruit sellers, shoemakers and mechanics advocate gold color in esthetic areas. d. Physical condition of the patient: 1. Patients with normal physical fitness can stay on the dental chair for the required time without creating any troubles. 2. Debilitated patients cannot tolerate long work on the dental chair. They prefer cast restorations or short-term restorations. 3. Handicapped patients prefer short term restorations. e. Educational and social conditions of the patient: 1. Educated patient advocate the most suitable restoration according to their satisfaction. 2. Less educated persons prefer esthetic restoratives. 3. Uneducated patients agree with the operator selection for the suitable restoration. f. Mental condition of the patient: 1. Normal persons can easily be satisfied with the most suitable restoration according to the knowledge introduced by the dentist. 2. Psychic patients cannot withstand treatment for long time and prefer esthetic restorations. g. Patient’s habits: 1. Patients with smoking habit suffer from stains on rough surfaces in the oral cavity and from acidic saliva. 2. Alcoholics always suffer from solubility of dental cements. 3. Persons with bruxism need strong restorations with high surface hardness. h. Economic condition of the patient: 1. Wealthy persons select the best restoration whatever it costs. 2. Ordinary people should be informed about the expenses before starting the restorative procedures. 3. Poor patients prefer amalgam in posterior teeth and glass-ionomers for esthetic restorations. 6 B- Factors related to the condition of the oral cavity: a. Oral hygiene: 1. Oral hygiene is the practice of keeping the mouth clean to prevent dental problems (mainly tooth decay and gum disease) and bad breath. 2. Patients with good oral hygiene are ideal candidates for all types of permanent restorations and should be instructed to maintain this condition after restoration of the tooth defects. 3. Patients with poor oral hygiene should improve and maintain their mouths clean before the restorative procedures to decrease periodontium inflammation that may affect restorations placement and to decrease the acidity of saliva which may affect the success of the restoration. b. Caries incidence: 1. Selection of suitable restorations for patients with high caries risk should be done cautiously to prevent failure of the restorations due to recurrent caries. 2. Teeth with rampant caries are better to be treated with glass-ionomer restorations as intermediate restorations until the condition subsides. 3. Short-term regular checkup every 3 months is important to discover any progress of new carious lesions for high caries risk patients to be treated early. c. Condition of occlusion: 1. Normal occlusion has no troubles in the selection of the suitable restorations. 2. Conditions of malocclusion such as anterior or posterior cross bite, severe overlap, plunger cusp and tilted teeth must be treated before the selection of the suitable restorations. d. Presence of metallic restoration: 1. Existing metallic restoration is important for the selection of new metallic restorations. As presence of different metallic restorations may lead to galvanic shocks. C- Factors concerning the tooth to be restored: a. Position of the tooth: 1. Anterior teeth are better to be restored with esthetic tooth-colored restorative materials. 2. Teeth that appear during smiling should be restored with esthetic materials. 3. Teeth which may act as abutment for fixed bridge, can be restored with amalgam or resin composite or reinforced glass-ionomer restorations. 4. Wisdom teeth are difficult to be isolated by rubber dam application. It is advisable to restore them with zinc free amalgam, cast gold restorations or glass ionomer restoration if they are not subjected to heavy occlusal forces. 7 b. Teeth with slight mobility: According to the grade of mobility, it is advisable to fix these teeth together by splinting. c. Form of the tooth: 1. peg-shaped lateral incisors should be restored with full coverage esthetic restorations. 2. Mulberry molars should be corrected occlusally with full coverage 3. Normal teeth should be restored with the suitable restorative material d. Condition of calcification: 1. Hypocalcified teeth with friable enamel should be restored with strong restoration to protect their cavity margins. 2. These teeth indicate the use of cast gold or ceramic restorations 3. Contraindicated to restorations that need strong condensation forces. e. Size and condition of the remaining coronal portion: 1. If the remaining coronal portion cannot confine the restoration and are greatly destructed so that extra means of retention or indirect restorations are advisable. f. Vitality of the pulp: 1. It is advisable to preserve pulp vitality. 2. In deep cavities, apply calcium hydroxide then suitable base material in deep areas to protect the pulp from thermal, chemical or traumatic irritation of the restorative material or its technique. 3. Teeth with hyperemic pulp should be restored with a suitable temporary restorative material until the irritational condition is relieved and then restored permanently with a suitable restoration. D- Factors related to the cavity to be restored: a. Size of the cavity: 1. Relatively small cavities and medium size cavities can be restored with amalgam, resin composite, or glass ionomer restorative materials. 2. Large cavities should be restored with resin composite or indirect restorations. b. Location of the cavity: 1. Occlusal cavities should be restored with metallic or ceramic restorations to withstand occlusal loads. 2. Mesial cavities in anterior teeth and premolars should be restored with esthetic restoratives. 3. Distal cavities of cuspids and bicuspids and molars can be restored with metallic restorations. 4. Labial cavities and cervical cavities of anterior teeth should be restored with esthetic restorative materials. 8 5. Cervical cavities of posterior teeth may be restored with amalgam, resin composite or glass ionomer restorations. 6. Subgingival cavities are better to be restored with cast gold or ceramic restorations or glass- ionomer restorations. c. Accessibility to the cavity: 1. Wide mouth opening provides enough accessibility. However, smallmouth opening creates difficulty in cavity preparation and restoration. 2. Anterior teeth, premolars and first molars are more accessible than second and third molars. III- Factors related to the dentist (operator): 1- Dentist should know full information about population needs. 2- He should have sufficient information about all available restorative materials. 3- He should have sufficient skill for manipulation and handling of restoratives. 4- He should use the material within its indications. 5- He should provide his patients with sufficient post-restorative instructions. To summarize For selecting a suitable restorative material, the following should be considered Good Luck 9