Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear

Abstract Objective To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. Methodology Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva – 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS – Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (μm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). Results For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. Conclusion The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.

摘要
研究目的：评估含硅酸钙/磷酸钠/氟化物的牙膏，联合或不联合强化精华液（boost serum, BS），针对牙釉质与牙本质侵蚀性牙磨损（erosive tooth wear, ETW）的防护效果。
研究方法：采用牛牙釉质及牙本质标本，构建侵蚀-磨耗循环模型：以1%柠檬酸（pH 3.6，作用2分钟）/人工唾液（作用60分钟）为循环介质，每日4次，持续5天。每日以对应牙膏进行2次刷牙，每次15秒（牙膏浆剂浸泡2分钟），共设4组牙膏（每组n=10）：无氟对照组（Weleda）、精氨酸/钙/单氟磷酸钠组（Arg/Ca/MFP，Colgate Pro-Relief）、硅酸钙/磷酸钠/单氟磷酸钠组（Si/PO4/MFP，Regenerate-Unilever），以及硅酸钙/磷酸钠/单氟磷酸钠联合强化精华液组（Si/PO4/MFP+双相BS——Advanced Enamel Serum，Unilever）。分别于第1天通过表面显微硬度（surface microhardness）评估各处理对侵蚀组织的影响；于第3天和第5天通过轮廓测厚仪（profilometry，单位μm）检测ETW所致的表面缺损量（surface loss, SL）。另设置额外牙本质标本（每组n=5），进行20000次刷牙循环以验证各牙膏的磨蚀性。数据采用方差分析（ANOVA）与相关性检验进行统计学分析，检验水准为5%。
研究结果：牙釉质层面，各处理组的表面显微硬度无显著差异，5天后的表面缺损量亦无统计学差异；牙本质层面，Si/PO4/MFP/BS组的表面显微硬度更高，但所有组别均未较无氟对照组呈现显著更低的表面缺损量；表面缺损量与牙膏磨蚀性之间无显著相关性。
研究结论：含硅酸钙/磷酸钠的牙膏联合强化精华液可提升侵蚀后牙本质的表面显微硬度，但与无氟对照牙膏相比，并未显著降低牙釉质与牙本质的缺损量；各牙膏的磨蚀性无法预测其对ETW的防护效果。