Peter Tschoppe

Enamel and dentine remineralization by nano-hydroxyapatite toothpastes

OBJECTIVES This in vitro study evaluated the effects of nano-hydroxyapatite (n-HAp) toothpastes on remineralization of bovine enamel and dentine subsurface lesions. METHODS Specimens were demineralized, randomly divided into five groups, and exposed to an aqueous remineralizing solution for two and five weeks (37 °C). Brushing procedures were performed with the respective toothpaste/storage solution slurry twice daily (2 × 5 s; total contact time of the slurries 2 × 120s/d): storage in remineralizing solution only (0); additional brushing with B (20 wt% zinc carbonate nano-hydroxyapatite, ZnCO(3)/n-HAp); BS (24 wt% ZnCO(3)/n-HAp); E (0.14 wt% amine fluoride); or A (7 wt% pure n-HAp). Differences in mineral loss (ΔΔZ) before and after storage/treatment were microradiographically evaluated. RESULTS Dentine groups 0, B, BS, and A showed significantly higher ΔΔZ values compared to E (p < 0.05; ANOVA). Enamel ΔΔZ values of group A were significantly higher compared to group E (p < 0.05), whilst no significant differences of these groups could be observed compared to 0, B, and BS (p > 0.05). CONCLUSIONS With the in vitro conditions chosen, toothpastes containing n-HAp revealed higher remineralizing effects compared to amine fluoride toothpastes with bovine dentine, and comparable trends were obtained for enamel.

Effect of fluoridated bleaching gels on the remineralization of predemineralized bovine enamel in vitro

OBJECTIVES This study evaluated possible differences regarding the remineralization of predemineralized enamel after exposure to fluoridated or non-fluoridated bleaching gels. METHODS 120 enamel specimens were prepared from sixty bovine incisors; before and after demineralization (37 degrees C; pH 4.95; 10d), one-quarter of each specimens surface was covered with nail varnish (control sound/demineralized). Subsequently, the specimens were stored for 16h daily in a remineralizing solution (pH 7.0; 14d), while for the remaining time (8h) various bleaching gels were applied: (1) no treatment (control), (2) Opalescence regular (O, Ultradent), (3) Opalescence PF (O-PF), (4) Nite White ACP (NW-ACP, Discus Dental) and (5) Nite White ACPF (NW-ACPF). Following, half of the bleached parts were nail-varnished and stored for another 3-weeks period in a remineralizing solution. Differences in mineral losses (DeltaDeltaZ) and lesion depths (DeltaLD) before and after treatment/remineralization period were evaluated from microradiographs. DeltaDeltaZ(surface) values (mineral loss of the outer 18microm of the lesion) were calculated. RESULTS After 2 and 5 weeks DeltaDeltaZ/DeltaLD values of the bleaching groups did not differ significantly from the controls. Treatment with NW-ACPF for 2 weeks resulted in significantly lower DeltaDeltaZ values compared to NW-ACP (p=0.032) and NW-ACPF in higher values than Opalescence regular (p=0.006). Two weeks treatment with O and O-PF resulted in decreased DeltaDeltaZ(surface) values compared to control (p<0.0005), whereas with NW-ACPF no significant differences could be observed (p=0.062). Application of NW-ACP induced significantly increased DeltaDeltaZ(surface) values compared to control (p=0.001). CONCLUSIONS No supporting influence of fluoride-containing bleaching gels on remineralization could be observed.

Effect of fluoride gels and mouthrinses in combination with saliva substitutes on demineralised bovine enamel in vitro.

OBJECTIVE 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. METHODS 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. RESULTS 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). CONCLUSIONS 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.

Saliva substitute in combination with high-concentrated fluoride toothpaste: effects on demineralised dentin in vitro.

OBJECTIVES The aim of this in vitro study was to assess the effects of saliva substitutes (modified with respect to calcium, phosphates, and fluorides) in combination with a high-concentrated fluoride toothpaste on demineralised dentin. METHODS Before and after demineralisation of bovine dentin specimens (subsurface lesions; 37 degrees C, pH 5.0, 5 d), one-quarter of each specimens surface was covered with nail varnish (control of sound/demineralised tissue). Subsequently, specimens were exposed to original Saliva natura (saturation with respect to octacalciumphosphate [S(OCP)]: 0.03; SN 0), or to three lab-produced Saliva natura modifications (S(OCP): 1, 2, and 3; SN 1-3) for 2 and 5 weeks (37 degrees C). An aqueous solution (S(OCP): 2.5) served as positive control (PC). Two times daily (2min each), Duraphat toothpaste (5000ppmF(-); Colgate)/saliva substitute slurry (ratio 1:3) was applied gently. Differences in mineral losses (DeltaDeltaZ) and lesion depths (DeltaLD) between values before and after exposure were microradiographically evaluated. RESULTS After both treatment periods specimens immersed in SN 0 revealed significantly higher mineral losses (lower DeltaDeltaZ values) and lesion depths (lower DeltaLD) compared to PC (p<0.05; ANOVA). After 5 weeks, specimens stored in SN 1 and 2 showed significantly higher mineral losses compared to PC (p<0.05), while those stored in SN 3 showed similar results (p>0.05). No differences in mineral loss could be observed between SN 2 and 3 (p>0.05). CONCLUSIONS Under the conditions of this limited protocol, the combination of Saliva natura solutions slightly saturated with respect to OCP in combination with a high-concentrated fluoride toothpaste enabled remineralisation of dentin in vitro.

Effects of Carboxymethyl Cellulose-Based Saliva Substitutes with Varying Degrees of Saturation with Respect to Calcium Phosphates on Artificial Enamel Lesions

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 (SOCP) 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, SOCP 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.

Evaluation of the remineralising capacities of modified saliva substitutes in vitro

OBJECTIVE In this in vitro study the effects of various calcium and phosphate additions to a commercially available saliva substitute on remineralization of demineralised dentin were investigated. DESIGN Bovine dentin specimens (n=70) were prepared. Before and after demineralisation (37 degrees C, pH 5.0, 5 days), one-quarter of each specimens surface was covered with nail varnish (control sound/demineralised tissue). Specimens were exposed either to original Saliva natura (SN 0) or to three modified versions (SN 1, SN 2 and SN 3) formulated with different degrees of saturation with respect to octacalciumphosphate (OCP) and dicalcium phosphate dihydrate (DCPD) for 2 and 5 weeks (37 degrees C). An aqueous solution (Buskes remineralizing solution) served as positive control (PC). Differences in mineral loss (deltadeltaZ) and lesion depth (deltaLD) before and after storage were evaluated from microradiographs. RESULTS After both storage periods dentin specimens immersed in SN 0 revealed significantly higher mineral losses (indicated by deltadeltaZ) and higher lesion depths (indicated by deltaLD) compared to all other solutions (p<0.05; ANOVA). Specimens stored in SN 1 and 3 showed significantly higher mineral losses compared with PC (p<0.05). No differences could be observed between SN 2 and PC (p>0.05). Only SN 2 significantly remineralized from 2 to 5 weeks storage (p<0.05; t-test). CONCLUSIONS An experimental Saliva natura solution (SN 2) with S(OCP)=2 and S(DCPD)=1.4 showed highest remineralizing capacity. Similar or better remineralization could not be achieved with slightly higher or lower saturated solutions.

Effects of regular and highly fluoridated toothpastes in combination with saliva substitutes on artificial enamel caries lesions differing in mineral content.

OBJECTIVE For patients with hyposalivation fluorides are supportive to prevent caries lesions. Remineralization of subsurface lesions might be improved by toothpastes containing 5000 μgF(-)/g compared with those having 1400 μgF(-)/g. This could be influenced by the degree of baseline mineralization. Therefore, this in vitro study evaluated the effects of fluoride toothpastes differing in fluoride concentration in combination with de- and remineralizing saliva substitutes using two lesion types. DESIGN Specimens with shallow (SL; ΔZ (SD): 1915 (543) vol% × μm) or deep lesions (DL; 5804 (427) vol% × μm) were either stored in mineral water [saturation with respect to octacalcium phosphate (S(OCP)): 0.5], demineralizing experimental (Exp, S(OCP): 0.3), demineralizing commercial (Glandosane, S(OCP): 0.3), or remineralizing saliva substitute (modified Saliva natura; S(OCP): 1.9) for five weeks (37 °C). Either one of three brushing procedures was performed additionally three times daily: no brushing, Elmex anticaries toothpaste (E; 1400 μgF(-)/g), Duraphat toothpaste (D; 5000 μgF(-)/g). Mineral parameters before and after storage were evaluated using microradiographs. RESULTS Storage in Exp as well as Glandosane induced a significant demineralization (p < 0.05; relatively more pronounced in SL than DL). Additional brushing in particular with D reduced these effects. Storage alone in modified Saliva natura remineralized specimens (p < 0.05). CONCLUSIONS Under the in vitro conditions chosen shallow lesions seem to be more susceptible for demineralization compared with deeper ones when stored in an undersaturated (with respect to OCP) saliva substitute. The highly fluoridated toothpaste seemed to be more beneficial than a regular one.

Saliva substitutes in combination with highly concentrated fluorides and brushing: in vitro effects on enamel subsurface lesions.

Hyposalivation is often associated with high caries activity, in particular in patients undergoing irradiation in the head/neck area. Besides the use of saliva substitutes to relieve the oral symptoms, daily application of fluoride gels or toothpaste (5,000 µg F–/g) is recommended for caries prevention. The aim of this study was to evaluate potentially remineralising effects of these fluoride agents in combination with saliva substitutes on enamel subsurface lesions. Demineralised bovine specimens were either stored in mineral water [control; saturation with respect to octacalcium phosphate (SOCP): 0.8], a demineralising saliva substitute (Glandosane; SOCP: 0.3) or in a modified (with respect to SOCP) saliva substitute [Saliva natura (SN); SOCP: 1.9] for 5 weeks (37°C). The following treatments were applied twice daily (11–13/group): no treatment (0), ProSchmelz fluoride gel (PS; 10 min application), Duraphat toothpaste (DP; 10 s; brushing with toothpaste/storage solution slurry), combination of DP+PS. Mineral parameters before/after storage were evaluated from microradiographs. Storage in Glandosane led to significant demineralisation (p < 0.05; paired t test), whereas additional use of fluoride agents neutralised the demineralising effect (p > 0.05). Storage in water alone resulted in no changes in mineral parameters (p > 0.05), whereas in combination with fluorides remineralisation could be shown (p < 0.05). For SN alone, remineralisation was observed (p < 0.05), but no additional beneficial effects of fluorides were detected. Under the conditions chosen, the fluoride agents reduce the demineralising effects of Glandosane and promote the remineralisation of specimens stored in water. Remineralising effects of SN could not be enhanced by the fluorides.

Mineral distribution of artificial dentinal caries lesions after treatment with fluoride agents in combination with saliva substitutes

OBJECTIVE Some saliva substitutes have been shown to demineralize dentine in vitro. This effect is counteracted by the application of various fluorides. In contrast, remineralizing saliva substitutes might be supported by these treatments, depending on the dynamics during remineralization. The aim of this in vitro study was to evaluate the effects of fluoride mouthrinses or gels in combination with de-/remineralizing saliva substitutes on dentinal subsurface lesions. DESIGN Demineralized bovine dentine specimens were stored either in mineral water [saturation with respect to octacalcium phosphate (S(OCP)): 0.7], Glandosane (G, S(OCP): 0.3) or in a modified saliva substitute Saliva natura (SN, S(OCP): 1.9) for five weeks (37°C). Fluoride agents were applied twice daily for 10 min (n = 15/group): no treatment, Meridol mouthrinse, Elmex sensitive solution, ProSchmelz fluoride gel, Elmex gelée. After storage thin sections were prepared and mineral losses before and after storage were evaluated from microradiographs. RESULTS Specimens stored in G alone showed significantly higher mineral loss compared to those stored in water, SN or G in combination with any additional treatment (p < 0.05). Storage in SN and treatment with ProSchmelz fluoride gel led to significantly higher remineralization compared to all other groups (p < 0.05) and resulted in distinct mineral gain within the lesion body. CONCLUSIONS Under the in vitro conditions chosen, use of fluoride agents in combination with a demineralizing saliva substitute resulted in reduced mineral loss. Storage in modified Saliva natura in combination with the application of ProSchmelz fluoride gel induced the most pronounced remineralization also of deeper lesion areas.

Conservative, Surgical, and Prosthetic Treatment of a Patient with a Periapical Lesion Associated with an Atypical Intraoral Sinus Tract

This report describes a clinical case with an atypical intraoral sinus tract formation from diagnosis and treatment to short-term outcome and definitive prosthetic rehabilitation. In detail, the patient underwent conservative nonsurgical root canal treatment followed by guided bone augmentation of the regions involved in periapical inflammation and sinus tract formation. The removal of the inflammatory source of the lesion as well as the affected tissue clearly led to a healing of the surrounding bone tissues. Subsequently, the tooth was reconstructed using a fibreglass post and a metal-ceramic crown; an implant was successfully placed in the previously inflamed bone region.