class I for composite pdf.pdf

CLASS I COMPOSITE D r. E m a d B a y o u m i B.Sc., 2007, M.Sc., 2014 PhD., 2021 • A bitewing radiograph should be obtained and evaluated to ensure that no proximal caries is evident. Class I composite Shade Selection: It has a profound impact on patient psychology i. ii. iii. iv. v. Tooth...

CLASS I COMPOSITE D r. E m a d B a y o u m i B.Sc., 2007, M.Sc., 2014 PhD., 2021 • A bitewing radiograph should be obtained and evaluated to ensure that no proximal caries is evident. Class I composite Shade Selection: It has a profound impact on patient psychology i. ii. iii. iv. v. Tooth of interest and opposing should be Free of plaque Quickly to avoid eye fatigue Under natural day light source Tooth should be moist with saliva; as dryness results in whiter appearance. Lipstick should be removed GENERAL Considerations during tooth preparation for class I composite: • Occlusal contact must be recorded and should be no contact in memorized in the interference • Creating access to the faulty structure • Removal of the faulty structure; caries, defective restorations, or material if present • Creating convenience form for restoration • Retention is obtained by bonding. • It is not necessary to incorporate mechanical retention features in tooth preparation when placing posterior composite Class I composite General considerations during tooth preparation for Class I composite: Do not require typical resistance and retention features. The initial pulpal depth is ~ 0.2mm inside dentin-enamel junction but may not be uniform. These preparations are prepared by Rounded or Elongated diamond bur in a very conservative manner. Class I composite General considerations during tooth preparation for class I composite: • The size and shape of the instruments generally are dictated by the size of the lesion. • Both carbide and diamond bur instrument can be used effectively. Class I composite General considerations during tooth preparation for class I composite: It should be noted that diamond Burs create a thicker smear layer which might make bonding more difficult for self etch bonding system. Class I composite General considerations during tooth preparation for class I composite: • The objective of tooth preparation is to remove all the caries of the faulty structure, as conservative as possible. • i.e; the preparation should never excessively extend beyond removal of faulty structure to justify resistance and retention forms, as this will weaken the tooth structure because composite is bonded to the tooth structure. Class I composite General considerations during tooth preparation for class I composite: • The pulpal floor is prepared to an initial depth ~ 0.2 mm inside dentin-enamel junction. • The instrument is moved mesially following the central groove and may fall and rise at the dentin-enamel junction, the pulpal floor is usually moderately flat. • The cuspal and marginal ridge areas should be preserved as much as possible, although bonded composite would restore some of the strength at weakened unprepared tooth structure. Class I composite General considerations during tooth preparation for class I composite: • Extension into marginal ridges should results in at least 1.5 mm of the remaining tooth structure ? • To preserve the dentinal support of the enamel marginal ridge. • After extending outline forms, if any caries remains on pulpal floor, it should be removed with round bur or hand instruments. • No attempt is made to place bevel on the occlusal margins Class I composite General considerations during tooth preparation for class I composite: After extending outline forms, if any caries remains on pulpal floor, it should be removed with round bur or hand instruments. No attempt is made to place bevel on the occlusal margins. Class I composite General considerations during tooth preparation for class I composite: • When final tooth preparation is judged to be near the pulp, the operator may use a base material before placing the adhesive and the composite. o If the remaining dentin thickness is between 0.5-1.5 mm Resin Modified Glass Ionomer Base (RMGI) is used. o If remaining dentin thickness (RDT) is less than 0.5 calcium hydroxide linear should be applied to the deepest aspect of the preparation, then protected with RMGI prior to adhesive placement. Class I composite General considerations during tooth preparation for class I composite: Matrix is not necessarily for Class I composite even when facial and lingual grooves are included. Phosphoric acid gel is applied 15 seconds over dentin and 30 seconds over enamel Then the bonding agent is applied to the entire preparation with micro-Brush, then adhesive thinning is made, then polymerized with light activation unit. Class I composite Class I composite General considerations during tooth preparation for class I composite: Composite insertion hand instruments or compule may be used to insert composite material. The syringe or the compule must be covered when not in use to prevent pre-mature hardening of the material. Small increments of composite are added (2 mm) and successfully light activated to maximize polymerization depth of cure. C-factor: ratio of bonded to unbonded surface; the higher the C-factor the higher the potential for composite polymerization shrinkage stresses. Class I composite General considerations during tooth preparation for class I composite: The incremental insertion and light activation of composite may reduce negative C-factor effect for class I. Also, the use of resin modified glass ionomer or flowable composite may also reduce the effect of polymerization shrinkage stresses due to the favorable elastic modulus. Class I composite Advantages of RMGI under composite RMGI bonded to dentin without opening the dentinal tubules, reducing post-operative sensitivity. Anti- cariogenic effect Favorable elastic modulus Decrease the C-factor effect Class I composite The enamel layer of a restoration should be placed respecting the anatomy of the tooth, the operator place and shape the composite before it is light activated, so that the composite restores the occlusal anatomy of the tooth. This will minimize the need for contouring and finishing after the composite is polymerized, furthermore this technique prevents damage of the restoration margins because it minimize the need to use rotary instruments to remove excess composite Class I composite Class I composite oThe anatomy is produced using: i. Fine composite spatula ii. Tine of explorer iii. Micro-brushes but never be saturated by bond. oComposite can be finished immediately after last incremental layer is cured. oFinishing is accomplished with appropriate polishing cups. Class I composite • Polishing cups. Class I composite Contra-indications of class I composite • High caries incidence. • Abnormal occlusal stress. • Isolations difficulties. • Patient’s allergic reactions to resin composite. Class I composite Advantages of class I composite v. Repairable. vi. No corrosion. vii.No health hazards. i. Esthetical purpose. ii. Conservation purpose. iii. Strengthening. iv. Bonded to tooth structure. viii.Cheaper than ceramics Class I composite Disadvantages of class I composite      Technique sensitive. Longer time than amalgam. Risk at microleakage and caries. Low fracture toughness. Polymerization shrinkage effects. Class I composite Disadvantages of class I composite Technique sensitive. Longer time than amalgam. Risk at microleakage and caries. Low fracture toughness. Polymerization shrinkage effects. Class I composite “Every tooth in a man's head is more valuable than a diamond.”