目的

探讨唾液及共鸣腔对基于共振频率分析种植义齿修复螺丝稳定性的影响。

方法

修复下颌牙列缺失的6个种植体联合支持螺丝固位义齿作为模型，以置于普通室内环境为对照组，以置于仿头模内人工唾液湿润模拟的口腔环境为研究组，使用数显扭矩扳手调整不同位置修复螺丝的预紧扭矩，形成与修复螺丝稳定性关联的参数矩阵，予以振动激发并采集相关声振信号加以处理，获取对应共振频率，绘制时频图，计算两组各修复螺丝在15 N·cm 时的共振频率及变异系数。应用Bland-Altman 一致性分析法评估两组各修复螺丝稳定性相关共振频率的一致性，应用Pearson相关性分析探讨两组各修复螺丝稳定性与相应共振频率的关系（α=0.05）。

结果

时频图结果显示，两组均在7 ～9 kHz 频道范围内出现能量集中带，且随着扭矩值降低，能量集中带出现左移。变异系数结果显示，实验组各修复螺丝在15 N·cm时共振频率介于（7 329±8）～（8 400±8）Hz，变异系数为0.001 ～0.002。对照组各修复螺丝在15 N·cm时共振频率介于（7 329±6）～（8 463±11）Hz，变异系数为0.000 8 ～0.002。Pearson相关性分析结果表明，两组各修复螺丝稳定性与共振频率均呈线性正相关（r=0.483 ～0.937，P＜0.001），且同一修复螺丝的相关系数值相近。Bland-Altman一致性分析结果显示，实验组归一化后的共振频率介于0.569 ～0.892，对照组归一化后的共振频率介于0.585 ～0.881，两组的共振频率差异无统计学意义（t=-1.816 ～0.859，P＞0.05），差值绝对值为0.001 ～0.016。

结论

湿润和共鸣的口腔环境未对基于叩诊的种植义齿声振特征分析产生不利影响，以共振频率反映修复螺丝稳定性具有良好的临床应用前景。

Objective

To explore the impact of saliva and resonance cavities on the stability of prosthetic screws based on resonance frequency analysis.

Methods

Mandibular edentulous gypsum casts with screw-retained definitive fixed dental prostheses supported by 6 implants were used.The control group was placed in a standard indoor environment，while the experimental group was placed in a simulated oral environment with artificial saliva in a dental manikin.Different insertion torques were applied to the screws using a digital torque wrench，forming a parameter matrix related to screw stability.A tapping simulation was directly applied to the buccal side of the tested screw，and a pickup device was used to collect the acoustic signals.The resonance peak frequencies of these signals were extracted by using time-frequencydomain analysis based on short-time Fourier transform.The spectrograms of acoustic signal were plotted，and the coefficients of variation for each prosthetic screw at 15 N·cm were calculated for both groups.Bland-Altman analysis was used to evaluate the consistency of the resonance frequencies related to prosthetic screw stability in both groups.Pearson correlation analysis was conducted to investigate the relationship between prosthetic screw stability and corresponding resonance frequencies（α = 0.05）.

Results

The spectrograms of acoustic signal showed that both groups had energy concentration bands in the 7 to 9 kHz range，and as the insertion torque value decreased，the energy concentration band shifted left.The coefficient of variation results indicated that the resonance frequencies of the prosthetic screws in the experimental group at 15 N·cm ranged from（7 329±8）Hz to（8 400±8）Hz，with coefficients of variation ranging from 0.001 to 0.002.In the control group，the resonance frequencies ranged from（7 329±6）Hz to（8 463±11）Hz，with coefficients of variation ranging from 0.000 8 to 0.002.Pearson correlation analysis showed that a linear positive correlation between screw stability and resonance frequency in both groups（r=0.483 ～0.937，P＜0.001）and the correlation coefficient values for the same screw were similar.Bland-Altman analysis revealed that the normalized resonance frequencies in the experimental group ranged from 0.569 to 0.892，while those in the control group ranged from 0.585 to 0.881.The differences in resonance frequencies between the two groups were not statistically significant（t=-1.816 ～0.859，P＞0.05），with the absolute difference ranging from 0.001 to 0.016.

Conclusions

The moist and resonant oral environment did not have an adverse effect on the acoustic-vibration characteristics of implant prostheses based on tapping.Acoustic resonance frequency analysis showed good clinical prospects for reflecting the stability of the prosthetic screw.