Background: Alterations of the vertical dimension of occlusion may affect masticatory muscle function, which is critical in pre-prosthetic planning, especially in Class II division 2 malocclusions. This study aimed to evaluate the impact of increasing VDO on the myoelectric activity of masticatory muscles using surface electromyography (EMG). The null hypothesis was that a 2–4 mm increase in VDO does not significantly influence muscle activity. Methods: Nine patients with Class II division 2 malocclusion were evaluated. EMG recordings of the masseter and anterior digastric muscles were obtained using the BioEMG II system (BioResearch Asoc., Milwaukee, WI, USA) and Biopak™ software (AcqKnowledge 4.x). VDO was increased using the Dupas universal jig. EMG was recorded for 30 s under six conditions: resting posture, intercuspal position (IM), swallowing, resting posture after VDO increase, IM with increased VDO (IM2), and swallowing with increased VDO (swallowing 2). Results: Most EMG variables showed no statistically significant differences after short-term VDO increase. Significant differences were observed only in the resting activity of both masseter muscles and in the right masseter during maximum intercuspation. No significant changes were identified during swallowing. Conclusions: Within the limitations of this pilot study, a 2–4 mm increase in VDO appears to produce minimal short-term changes in masticatory muscle activity in Class II division 2 patients. These findings should be interpreted with caution due to the small sample size and short observation period, and further studies are required to evaluate long-term neuromuscular adaptation.

Background: Dentin disinfection plays an important role in prosthodontics, reducing the microbial load, preventing postoperative complications and enhancing the bond strength. This in vitro study aims to evaluate the antimicrobial efficacy of different dentin disinfection protocols, depending on microorganism type, application time, and dentin depth. Methods: A total of 144 extracted human molars were included in the final analysis. The exposed dentin surfaces were contaminated with methicillin-resistant Staphylococcus aureus (MRSA) or Candida albicans (C. albicans). The specimens were disinfected using 2% chlorhexidine digluconate, 3% hydrogen peroxide, or photodynamic therapy with 1% toluidine blue. Microbial growth at superficial and deep dentin was assessed using semi-quantitative visual colony-density scores, resulting in 288 microbiological measurements. Ordinal generalized estimating equation (GEE) models, accounting for within-tooth correlation, were used to evaluate the factors associated with microbial scores. Results: The results showed statistically significant differences among protocols for MRSA (Wald χ² = 62.98; df = 5; p < 0.001) and for C. albicans (Wald χ² = 18.77; df = 5; p = 0.002). Specifically, 2% CHX applied for 30 s was associated with the greatest reduction in MRSA microbial scores (OR = 0.121; p = 0.009), whereas 3% H₂O₂ applied for 60 s was more effective against C. albicans (OR = 0.054; p < 0.001). PDT showed lower and less consistent antimicrobial effects under the tested parameters. Conclusions: The effectiveness of dentin disinfection depends on the microorganism, application time, and dentin depth. Complete elimination of the microbial load cannot be achieved using the disinfectants investigated.