orabase and octacalcium-phosphate

The present study investigated the effects of fluoride (F) concentration, lesion baseline severity (ΔZ(base)) and mineral distribution on lesion progression. Artificial caries lesions were created using three protocols [methylcellulose acid gel (MeC), hydroxyethylcellulose acid gel (HEC), carboxymethylcellulose acid solution (CMC)] and with low and high ΔZ(base) groups by varying demineralization times within protocols. Subsequently, lesions were immersed in a demineralizing solution for 24 h in the presence of 0, 1, 2 or 5 ppm F. Changes in mineral distribution characteristics of caries lesions were studied using transverse microradiography. At baseline, the protocols yielded lesions with three distinctly different mineral distributions. Secondary demineralization revealed differences in F response between and within lesion types. In general, lowΔZ lesions were more responsive to F than highΔZ lesions. LowΔZ MeC lesions showed the greatest range of response among all lesions, whereas highΔZ HEC lesions were almost unaffected by F. Laminations were observed in the presence of F in all but highΔZ HEC and CMC lesions. Changes in mineral distribution effected by F were most pronounced in MeC lesions, with remineralization/mineral redeposition in the original lesion body at the expense of sound enamel beyond the original lesion in a dose-response manner. Both ΔZ(base) and lesion mineral distribution directly impact the F response and the extent of secondary demineralization of caries lesions. Further studies - in situ and on natural white spot lesions - are required to better mimic in vivo caries under laboratory conditions.

Topics: Acetic Acid; Animals; Apatites; Calcium Fluoride; Calcium Phosphates; Carboxymethylcellulose Sodium; Cariostatic Agents; Cattle; Cellulose; Dental Enamel; Disease Progression; Dose-Response Relationship, Drug; Durapatite; Fluorides; Hydrogen-Ion Concentration; Lactic Acid; Methylcellulose; Microradiography; Minerals; Temperature; Time Factors; Tooth Demineralization; Tooth Remineralization

The aim of the present study was to evaluate the effects of experimental saliva substitutes based on carboxymethyl cellulose (CMC) differing in degrees of saturation with respect to calcium phosphates on the mineral loss of enamel in vitro. Demineralized bovine specimens (subsurface lesions) were exposed to one of six experimental CMC-based solutions with theoretical degrees of saturation with respect to octacalcium phosphate (S(OCP)) of S0, S0.5, S1, S2, S4, and S8 for 10 weeks. A previously studied saliva substitute (Glandosane) and two aqueous solutions (C0 and C1) served as controls. Mineral losses and lesion depths before and after storage were evaluated from microradiographs. Free and bound calcium as well as phosphate and fluoride concentrations were determined. According to these measurements, S(OCP) of S2, S4, and S8 was 0.3, 1.1, and 3.4, respectively. Storage in Glandosane and both negative controls resulted in significant demineralization (p < 0.05). Only S2 significantly remineralized the specimens (p < 0.05). All other solutions showed neutral effects. No significant differences in mineralization between S0 and C0 as well as between S1 and C1 could be observed (p > 0.05). It can be concluded that a CMC-based solution actually unsaturated with respect to octacalcium phosphate (S2) shows most pronounced remineralization capability under the conditions chosen. This might be explained by a more favorable balance between calcium bound to CMC in an adsorbed layer at the enamel-liquid interface and heterogeneous nucleation of calcium phosphates within a solution compared to solutions either supersaturated or having lower levels of saturation.

Topics: Adsorption; Animals; Calcium; Calcium Fluoride; Calcium Phosphates; Carboxymethylcellulose Sodium; Cattle; Dental Enamel; Durapatite; Fluorides; Materials Testing; Microradiography; Minerals; Phosphates; Saliva, Artificial; Time Factors; Tooth Demineralization; Tooth Remineralization

Besides the use of saliva substitutes, patients suffering from hyposalivation are instructed to apply fluoride products to prevent caries. Some saliva substitutes have been shown to demineralise enamel; an effect that might be counteracted by the application of fluoride gels or mouthrinses. Combined use of these products with remineralising or neutral saliva substitutes might result in more pronounced remineralisation.. Demineralised bovine enamel specimens were either stored in mineral water [W, control; saturation with respect to octacalcium phosphate (S(OCP)): 0.7], an experimental demineralising carboxymethylcellulose (CMC)-based solution (C, S(OCP): 0.3), or in a modified (S(OCP)) saliva substitute [Saliva natura (SN), S(OCP): 1.6] for five weeks (37 degrees C). After two weeks half of the exposed surfaces were nail varnished. The following treatments were applied twice daily for 10min each time (n=14-18/group): 1: no treatment, 2: Meridol mouthrinse, 3: Elmex sensitive mouthrinse, 4: ProSchmelz fluoride gel, and 5: Elmex gelée. Mineral parameters before and after storage were evaluated from microradiographs.. Specimens stored in C showed significantly higher mineral loss compared to W and SN (p<0.05; ANOVA). For C additional use of fluorides resulted in less demineralisation (p<0.05) compared to C alone. SN in combination with ProSchmelz led to significantly higher remineralisation compared to all other groups (p<0.05).. Use of fluorides reduces the detrimental effects of the demineralising solution. Treatment with ProSchmelz in combination with storage in a saliva substitute supersaturated with respect to OCP yielded to most pronounced remineralisation under the conditions chosen.

Topics: Analysis of Variance; Animals; Calcium Phosphates; Carboxymethylcellulose Sodium; Cariostatic Agents; Cattle; Dental Enamel; Drug Combinations; Fluorides, Topical; Microradiography; Mouthwashes; Saliva, Artificial; Tooth Demineralization; Tooth Erosion; Tooth Remineralization

This study investigated the effect of six lab-produced saliva substitutes based on carboxymethylcellulose (CMC) differing in octacalciumphosphate saturations (OCP-s) on mineralisation of bovine dentin in vitro.. Dentin specimens were prepared (n=234); prior to and after demineralisation (37 degrees C; pH 5.0; 7 d), one-third of each specimen surface was covered with nail varnish (control of sound dentin). Subsequently, specimens (n=13) were exposed to either one of the six CMC-based solutions (OCP-s: 0, 0.5, 1, 2, 4, and 8) at pH 6.5 or to Glandosane for 5 and 10 weeks (37 degrees C). Two aqueous solutions (OCP-s: 0 and 1) served as controls. After storage, thin sections were prepared and mineral loss was calculated by transversal microradiography.. After both storage periods specimens immersed in Glandosane revealed a significantly increased mineral loss compared to all other solutions (p<0.05; Bonferroni post hoc test). Control solution with OCP-s=1 induced a significant remineralisation (p<0.05; adjusted paired t-test). Only after 5 weeks exposure to the CMC-based solution with an OCP-s=2 a significant remineralisation compared to baseline (p<0.05) as well as a significantly increased mineral gain of the surface area compared to higher saturated solutions (p<0.05; Bonferroni post hoc test) could be observed.. CMC seems to hamper dentin remineralisation, although after 5 weeks a mineral gain could be induced with slightly supersaturated CMC-solutions with respect to OCP.

Topics: Animals; Bone Substitutes; Calcium Phosphates; Carboxymethylcellulose Sodium; Cattle; Dentin; Dose-Response Relationship, Drug; Hydrogen-Ion Concentration; In Vitro Techniques; Microradiography; Saliva, Artificial; Time Factors; Tooth Remineralization