The relationship between DT occlusion and DH resides in the concept that limiting the patency of these tubules might reduce fluid flow, hence diminishing the sensitivity of the nerves. Therefore, one of the major techniques for treating DH is to occlude these tubules, either by constructing a physical barrier or by precipitating crystalline deposits inside the tubules themselves [25]. This can be achieved through a variety of treatment modalities, including topical agents containing minerals such as calcium, phosphate or fluoride [26] which form insoluble precipitates, or lasers, which alter the morphology of the tubule entrances, creating a physical impediment to fluid movement [16, 17]. Tubule occlusion techniques are deemed successful; however, the longevity of such therapies varies depending on the chemicals utilized and the method of administration. Thus, continuing research into the effectiveness of different occluding substances and procedures is crucial to developing DH care and increasing patient outcomes. The effective management and decrease of DH comprise in-office treatments that may include fluoride varnishes, resin-based sealants and laser therapy as well as home care practices such as regular dental hygiene, desensitizing toothpastes or mouthwashes, and dietary changes [27]. In this in vitro study, a power analysis was performed to calculate the appropriate sample size. It was demonstrated that both mouthwash with 1.4% dipotassium oxalate and 810 nm diode laser treatments alone may occlude DT, with the combination of the two exhibiting the most promising outcomes. These results might have significant consequences for professionals pursuing more effective therapies for DH, which impacts oral health-related quality of life.

The mechanism of potassium oxalate in occluding tubules is well understood. It interacts with dentinal fluid calcium to generate insoluble calcium oxalate crystals, which occlude the tubules and reduce hypersensitivity [28]. The diode laser, on the other hand, presumably aids in this process via heat effects that modify the dentin surface structure, further helping in tubule occlusion [16]. Despite the overwhelming research on toothpastes, few studies have been published on the efficacy of desensitizing mouthwashes in lowering DH as an alternative delivery vehicle [29]. As a soluble oxalate, potassium-containing mouthwash exhibited considerable decreases in DH [28]. In a recent systematic review, the daily use of mouthwashes containing potassium salt effectively reduced DH for up to eight weeks without any side effects [15]. In contrast, Grandizoli et al. [30] investigated the effect of different mouthwashes including dipotassium oxalate and no mouthrinse was able to promote significant DT occlusion. Khot et al. [31] similarly compared different mouthwashes and completely occluded tubules in dipotassium oxalate group was found in only 33.3%. There are conflicting results in the literature in this area. In our study, a mouthwash with 1.4% dipotassium oxalate was applied to extracted human teeth, and occlusion of the DT was observed at the end of five days, confirming the effect of the potassium-based mouthwash. Nevertheless, the clinician is currently unable to determine the appropriate frequency and duration of mouthwash usage as an indicator of individual behavior. In addition, some patients might lose their enthusiasm in maintaining regular home care, which prompts dentists to search for extra help for maintenance.

The 810 nm diode laser was selected for use in the present study due to its favorable thermal effects, cost-effectiveness and widespread adoption compared to other soft and hard tissue lasers. Additionally, its DT occlusion capabilities are comparable to those reported in the literature. The findings from our study can be benchmarked against those from other diode laser studies conducted with varying application parameters, thereby assisting clinicians in developing optimal study protocols. Diode laser treatment is known to partially seal DT in addition to its analgesic effect [32]. In contrast to home care procedures such as toothpastes and mouthwashes, the diode laser has the established benefit of providing instant effectiveness in DH [33]. However, one must pay extra care not to produce permanent changes in the pulp owing to the lateral thermal impact of the diode laser. Therefore, characteristics such as the output power and time of application are highly important for producing the optimum effect. The low output power and one-time-use of the diode laser in the present study led to favorable DT occlusion. Nonetheless, the single application of the diode laser may be considered as a possible constraint, because there exists uncertainty regarding the delivery of enough DT occluding energy to the surface in one instance without causing pulp damage. There is no consistent application protocol in the literature on this subject. Sicilia et al. [33] used an 810 nm diode laser at an output power of 1.5–2.5 W for 1 min and observed a reduction in DH after 15 min with no side effects. Hashim et al. [19] obtained comparable instant impacts with the same wavelength at 1 W with a 1-minute application. Despite its rapid effectiveness, repeated administrations at various time periods may be required for the total resolution of DH in certain severe instances [18]. Saluja et al. [34] conducted a comparative analysis of the morphologic changes on DT induced by Nd: YAG, CO2 and 810 nm diode lasers, and observed that the diode laser exhibited the least effective outcome, with a mere 40% occlusion of DT. Nevertheless, the duration of the application in the aforementioned study was 30 s. In our study, an 810 nm diode laser was applied for one minute at an output power of 0.25 W, and the degree of occlusion of the DT was significantly greater (99%) than that in the control group. From the DT occlusion point of view, within the limits of this study, all test groups occluded significantly more DT than the control group (p˂0.01). However, strikingly, in terms of preventing DH, mouthwash containing 1.4% dipotassium oxalate occluded statistically significantly fewer tubules than laser (p˂0.01) or the combination of the two (p˂0.01). On the other hand, laser alone exhibited statistically equivalent outcomes compared to mouthwash alone (p > 0.05) or combination usage (p > 0.05). Although the relatively similar percentages of DT occlusion achieved in the various test groups were statistically significant, the clinical value of these data may be debatable. A recent study concluded that the combined use of an Er: YAG laser with 8% arginine-calcium carbonate does not yield better outcomes than does the use of a single agent [35]. These inconsistent findings may be explained by the varied treatment procedures employed. This highlights the need for future studies which should focus on the short and/or long-term effects of combined treatments and optimal application protocols and devices.

Any treatment must consider the comfort of the patient and minimize side effects. The in vitro format of this work limits its direct clinical usefulness; nonetheless, it provides basic insight that can influence future in vivo investigations. Future studies must evaluate these therapy modalities in a clinical context to determine their long-term effects, patient comfort, and possible side effects. Furthermore, the single-blind in vitro design of this study highlights the need for double-blind, randomized controlled trials with larger sample sizes. These investigations may yield more conclusive evidence of the safety and effectiveness of combination treatment, empowering medical professionals to make more knowledgeable judgments about the treatment of DH.