## 4 Discussion  
The present study assessed the efficacy of Pro-Argin technology (8% arginine and calcium carbonate) with respect to the OHRQoL when compared with a negative control over 24 weeks. Toothpaste with 8% arginine and calcium carbonate and its corresponding in-office desensitizing paste were compared with a pumice-based fluoride-free prophylaxis paste and an experimental sodium monofluorophosphate toothpaste. In general, all products were well tolerated during the entire treatment. The OHRQoL and CDH were evaluated at baseline and at 4, 8, and 24 weeks using the OHIP-49 and the GOHAI questionnaires (OHRQoL) as well as using the Schiff score and the VAS (CDH). [PERSON] and co-workers [20] have elucidated that dentine hypersensitivity is significantly related to OHRQoL. However, most of the clinical studies focused exclusively on the clinical parameters, so only a few results were found that dentine hypersensitivity directly related to OHRQoL. Studies by [PERSON] et al. [31] that are more recent have also shown an influence of dentine hypersensitivity on the OHRQoL. Therefore, the OHIP-49 is suitable for group comparisons in clinical studies. Another advantage of the OHIP-49 is that different investigators have to be calibrated exclusively for the clinical parameters. The difference between OHIP-49 scores after 24 weeks of treatment and the baseline scores was the primary outcome of the present investigation. The OHIP-49 formed the basis of the OHRQoL evaluation. A reduction in the OHIP-49 score was indicative of an improved oral condition. The Dentine Hypersensitivity Experience Questionnaire (DHEQ), formerly developed for assessing OHRQoL in the context of dentine hypersensitivity, as well as the short form of the OHIP (OHIP-14), could also have been considered for evaluation. However, the OHIP-49 was used in this clinical investigation due to its completeness and thus better comparability with regard to former investigations focusing on dentine hypersensitivity and quality of life [15,20]. According to the OHIP-49 scores, the test group (adjusted to baseline) showed a statistically significant improvement in the OHRQoL than the control group after 8 weeks (\(p\) = 0.030, ANCOVA) and after 24 weeks (\(p\) = 0.005, ANCOVA). These results were corroborated by the GOHAI questionnaire (\(p\) = 0.001, Mann-Whitney U test) after 24 weeks. The OHIP-49, its pain-relevant items, and the GOHAI questionnaire showed that the therapies in both randomization groups resulted in an improvement in the OHRQoL. In addition, the higher efficacy of the test product could be classified as clinically relevant. The overall improvement in both groups was also attributed \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Test Applied** & \(p\)**-Value** \\ \hline
**GOHAI screening** & [PERSON]–Whitney U & 0.442 \\
**GOHAI 24 weeks\(-\)baseline (unadjusted)** & [PERSON]–Whitney U & 0.001 * \\
**GOHAI 24 weeks\(-\)4 weeks (unadjusted)** & [PERSON]–Whitney U & 0.002 * \\
**GOHAI 24 weeks\(-\)8 weeks (unadjusted)** & [PERSON]–Whitney U & 0.132 \\
**GOHAI 8 weeks\(-\)baseline (unadjusted)** & [PERSON]–Whitney U & 0.057 \\
**GOHAI 8 weeks\(-\)4 weeks (unadjusted)** & [PERSON]–Whitney U & 0.117 \\
**GOHAI 4 weeks\(-\)baseline (unadjusted)** & [PERSON]–Whitney U & 0.506 \\ \hline \hline \end{tabular}  
* Statistically significant (\(p\) < 0.05); GOHAI: Geriatric/General Oral Health Assessment Index.  
\end{table} 
Table 6: Comparison of the GOHAI scores, statistical tests, and corresponding \(p\)-values. in part to an omnipresent placebo effect. In the case of a placebo effect, patients suggested a certain expectation of treatment success, such as a reminder of the improvement in symptoms after a visit to the doctor/dentist or after the intervention [32]. The placebo effect of the primary study parameter (OHIP-49 score) in the present study was 45%. [PERSON] and [PERSON] [33] reported that the non-specific effects of clinical studies were up to 75%.