Dental caries is a bacterially based disease. when it progresses, acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the carbonated hydroxyapatite mineral, a process called demineralization.
Pathological factors including acidogenic bacteria, salivary dysfunction and dietary carbohydrates are related to caries progression.
Protective factors which include salivary calcium, phosphate and proteins, salivary flow, fluoride in saliva and antibacterial component can balance, prevent or reverse dental caries(1). (John D.B. and Featherstone. 2000).
There is sufficient clinical evidence to prove that the process of white-spot formation which representing the initial demineralization in enamel sometimes reversed in percentage of about 50%(2,3). ( Fehr. et al. 1965& Backer Driks, O. 1966)
Although gaining full understanding of the remineralization process may be difficult, it is arguable that both physical and chemical processes are relevant. The site and amount of mineral deposition are probably determined by the physical condition (mineral distribution profile and transport mechanism) and by chemical process (deposition)(4).( Rubben J. et al. 1999). Therefore, the mineral distribution profile of the lesions should be considered as one of the important parameters is the study of remineralization.
In the laboratory it is relatively simple to produce demineralized lesions similar to the characteristic pattern of natural enamel and dentin lesions(5).(Featherstone J.D and Rodgers, B.E. 1981)
There is a little doubt that significant remineralization of enamel and dentin lesions can occur under both invitro and invivo conditions, and therefore, remineralization is increasingly accepted as a viable non invasive approach for restoring carious teeth , at least during the earlier stages of the caries process(6).(Chow, L.C and Vogel G.L. 2001).
Review of literature
Alessandri bonetti. et al. in 2009 (7) evaluated Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) effect on stripped enamel surfaces. He found that Interproximal enamel reduction (orthodontic stripping) leaves surface-roughness that encouraged plaque adherence. The effect of Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on stripped enamel morphology after exposure to an acid solution was evaluated qualitatively by means of scanning electron microscope (SEM). Conclusion was is that topical application of CPP-ACP could be effective in promoting enamel remineralization after interdental stripping.
S.Ranjitkar J.M. et al. in 2009 (8) investigated The effect of Caseinphosphopeptide-amorphous calcium phosphate on erosive enamel and dentin wear by toothbrush abrasion. He concluded that in addition to its role as a remineralizing agent in preventing dental caries, Casein phosphopeptide-amorphous calcium phosphate delivered as a mousse can reduce erosion of enamel and dentin. It was that Casein phosphopeptide-amorphous calcium phosphate reduced erosive tooth wear involving toothbrush, probably by remineralizing and lubricating eroded tooth surfaces, may have implications in management of tooth wear.
Rios D. et al. in 2009 (9) studied The efficacy of a highly concentrated fluoride dentifrices on bovine enamel subjected to erosion and abrasion. Researchers have proposed the use of fluoride for the prevention of enamel wear by means of fluoridated dentifrices.Tooth wear is a well recognized dental problem so that, the authors conducted a study to assess the efficacy of ahighly concentrated fluoride dentifrices on bovine enamel subjected to erosion and abrasion. The authors concluded that the highly concentrated fluoride dentifrice didn't have aprotective effect on enamel against erosion and erosion plus toothbrushing abrasion so patients at hight risk of developing enamel erosion should benefit from preventive measures other than fluoride dentifrice , because even ahighly concentrated fluoride dentifrice doesn't appear to prevent enamel erosion.
Altenburger MJ. et al. in 2009 (10) studied In situ fluoride retention and remineralization of incipient carious lesions after application of different concentrations of fluoride. They found that: The use of 1% fluoride fluid resulted in significantly higher remineralization compared with the use of 0.05% fluoride fluid. For both fluoride fluids mineral gain followed a linear relationship with time during the experimental period, indicating a possible further uptake of mineral, even after 4 weeks.
Puig-Silla M. et al. in 2009 (11) compared the remineralizing effect of a sodium fluoride mouthrinse to a sodium monofluorophosphate and calcium mouthrinse. The in vitro study showed that fluoride and calcium mouthrinse has a significantly greater remineralizing capacity than the fluoride mouthrinse with the same fluoride ion concentration under the in vitro conditions.
Aim of the study
This study aimed at:
Material and Methods
Materials:
Methods:
Sound enamel will be immersed in prepared artificial saliva for a selected period of time to produce caries-like lesion then, enamel will be treated with one of the investigated remineralizing agent according to manufacturer instructions.
I. Elemental analysis:
II. Optical properties:
Optical properties of the samples will be determined.
III. Mechanical testing:
The bovine enamel will be restored with disc samples of the selected aesthetic restorative materials and tested for bond strength.
References
