14The bond strength is primarily related to micro-mechanical bonding to theintertubular dentin which occuresbetween tubules along the cut dentinsurface.
15Dentin Bonding Agent, DBA Early DBA were hydrophobic, bondeddirectly to the dentin smear layer.Bond strengths＜6MPa.Later DBA removed the smear layer buttended to over-etch dentin.Bond strengths≈10~12MPa.
16DBA were chemically modified to be more hydrophilic.Bond Strengths≈18~20MPa.Careful dentin conditioning,Coupled with hydrophilic primer,Bond Strength≈22~35MPa.
17The Development of DBA Enamel etch (1955) Dentine etch (1960) Treatment of smear layer (1980)Wet Bonding technique(1990)
18First generationSecond generationThird generationFourth generation: Total etch techniqueFifth generation: One bottle systemSixth generation: All in one,2000Seventh generation
19Cavity Preparation Three designs of cavity preparation: 1.Conventional 2.Beveled conventional3.Modified
20Beveled conventional cavity preparations are similar to conventional preparation,in that the outline form has external,“box-like” walls, but with beveledenamel margin.
43Conservative Operative Dentistry Minimal intervention dentistryis regards as a main stream in caries treatment in the 21st century.
44Principles of Minimal Intervention dentistry Remineralization of early lesionsReduction in cariogenic bacteria, to elminate the risk of further demi-neralization and cavitationMinimum surgical intervention of ca-vitated lesionsRepair rather than replacement of defective restorations
45“The day is surely coming, and perhaps within the lifetime of you young menbefore me, when we will be engaged inpracticing preventive, rather than reparative, dentistry. ”GV Black in 1896