Therapeutic success in endodontic treatment depends on successful infection control. Alexidine dihydrochloride (ALX) was recently proposed as a potential alternative to 2% chlorhexidine (CHX) as it possesses similar antimicrobial properties, expresses substantivity and does not produce p-chloroaniline (PCA) when mixed with sodium hypochlorite (NaOCl). However, the products released in this reaction have not been described to date. The aim of this study was to identify detected chemical compounds formed in the reaction of ALX and NaOCl with the ultra-high-performance liquid chromatography–mass spectrophotometry (UHPLC-MS) method and assess whether precipitates and PCA are formed in this reaction. Solutions of ALX were mixed with the equivalent volume of 2% and 5.25% (w/v) NaOCl solutions. As control, 2% (w/v) CHX was mixed with 2% and 5.25% (w/v) NaOCl. Samples were subjected to the UHPLC-MS analysis. The mixture of ALX and NaOCl resulted in a yellowish precipitate formation, the amount of which depended on NaOCl concentration. Interaction of ALX and NaOCl resulted in the production of aliphatic amines. No PCA was formed when NaOCl was mixed with ALX. However, for the first time, we identified the possible products of the interaction. The interaction between NaOCl and ALX results in the formation of aliphatic amines; therefore, these compounds should not be mixed during endodontic treatment.

Background/Objectives: The purpose of this study was to indicate factors influencing the healing of maxillary sinusitis of endodontic origin (MSEO) after non-surgical endodontic treatment. Methods: The study was performed retrospectively on medical records and CBCT data of 114 teeth in 114 patients, who were referred to endodontic treatment between 2016 and 2024, performed by the same operator and according to the same treatment protocol. Fifteen factors were chosen for their possible influence on the healing of MSEO. Results: The rate of the complete healing of MSEO after RCT was 76.32%. The healing of MSEO was higher when CHX was applied in the final irrigation protocol (p = 0.022) and was less likely when there was a flare-up in-between visits or after obturation of the canals (p = 0.002). MSEO was more likely to heal when a tooth was treated in two appointments than with single-visit RCT (p = 0.012). The number of endodontic interventions significantly influenced the healing of MSEO, as it was less likely to heal when there was more than one endodontic retreatment for a tooth (p = 0.01). Conclusions: Within the limitations of this retrospective study, four factors significantly influenced the healing of MSEO, and these should be taken into consideration in obtaining treatment protocols for dental-induced sinusitis and the better assessment of the possible success of this non-invasive treatment approach.

Background/Objectives: Odontogenic infections range from localized abscesses to life-threatening deep neck infections and are a frequent cause of emergency admission. We aimed to identify prognostic factors for postoperative complications after their surgical treatment. Methods: We retrospectively analyzed 194 adults (59.3% male) treated at the Department of Cranio-Maxillofacial Surgery in Cracow between 2020 and 2025. The primary outcome was any postoperative complication, graded by the Clavien–Dindo classification and dichotomized into minor (grade I–II) and major (grade ≥ III). Prolonged hospitalization and prolonged irrigation (>7 days) were secondary outcomes. Pre-specified main factors (advanced age, diffuse phlegmonous spread, diabetes mellitus) and covariates (sex, maxillary location, systemic disease) were tested by uni- and multivariable logistic regression. Results: Comorbidities were present in 69.1%. Complications occurred in 49 patients (25.3%): 19 (9.8%) minor and 30 (15.5%) major, including 12 grade IV intensive-care events and two deaths (grade V). In multivariable analysis, diffuse phlegmonous spread independently predicted any complication (adjusted OR 11.7), major complication (OR 23.4), prolonged hospitalization (OR 5.02) and prolonged irrigation (OR 4.39; all p ≤ 0.004). Advancing age independently predicted major complications (OR 1.03 per year, p = 0.037). Both fatal cases shared phlegmon, maxillary location and diabetes. Conclusions: Diffuse phlegmonous spread was the principal prognostic factor across all adverse outcomes, with advancing age additionally predicting major complications. Because intensive-care admission occurred almost exclusively in phlegmon patients, this association is partly definitional. Early identification of diffuse spread and advanced age may support effective triage.

The etiopathology of maxillary sinusitis of dental origin (MSDO) is well established, and chronic apical periodontitis is the second most common cause of all dental-induced sinusitis incidents. The literature presents no common treatment protocols for MSDO and very few studies address the impact of root canal treatment (RCT) in its management. The literature presents cases of maxillary sinusitis resolution after performing a multivisit nonsurgical endodontic treatment, yet none described complete healing of MSDO as a result of single-visit nonsurgical RCT. This paper reports a case series of maxillary sinusitis of endodontic origin (MSEO) associated with upper maxillary molars that were successfully treated with single-visit nonsurgical antiseptic RCT. In all cases, the clinical symptoms subsided within a week after endodontic treatment. Control cone-beam computed tomography (CBCT) scan showed healing of periapical bone and total resolution of maxillary sinusitis symptoms. MSDO treatment protocol should start with nonsurgical antiseptic RCT. Single-visit nonsurgical endodontic treatment can be effective in MSEO management. CBCT is a method of choice in MSEO diagnostics. Endodontists are well trained and well equipped to treat MSDO, and the cooperation between ear, nose, and throat specialists, maxillofacial surgeons, and endodontists is crucial for both: good diagnostics and treatment.

Background/Objectives: Half of diagnosed unilateral maxillary sinusitis may have odontogenic origin, and root canal treatment (RCT) can be beneficial as a single-mode treatment for full resolution of maxillary sinusitis of endodontic origin (MSEO) symptoms. The aim of the study was to investigate the influence of passive ultrasonic irrigation (PUI) on the healing of MSEO after non-surgical endodontic treatment. Methods: A single-center, retrospective study was conducted on CBCT data and medical records of 240 patients, who underwent non-surgical endodontic treatment, performed by the same operator between 2016 and 2025. One hundred and thirty-six teeth entered the study due to inclusion/exclusion criteria. Results: Complete healing was observed in 75.74% of the cases (n = 103). The tooth most frequently associated with MSEO was the first upper molar (52.21%, n = 71). PUI was applied in 66.91% of the treatments (n = 91). PUI was an independent predictor of MSEO healing (p = 0.001; 95% CI [1.768; 9.136]). When PUI was introduced in RCT, complete healing of MSEO was observed in 84.62% of the cases (n = 77). PUI was independently associated with higher odds of radiological resolution of MSEO in univariate logistic regression (OR = 4.019) and multiple logistic regression (OR = 12.388) models. Conclusions: PUI application in the irrigation protocol was associated with higher rates of MSEO healing after non-surgical endodontic treatment (p = 0.001; 95% CI [1.768; 9.136]). The rate of MSEO healing after non-surgical RCT is high (75.74%); therefore it should be considered as a single-mode treatment option in cases of unilateral maxillary sinusitis.

Continuous improvement and technological progress in the field of microscopic endodontics enable a gradual increase in indications for non-surgical root canal treatment. While most publications report successful surgical management of overfill or extruded foreign bodies into the periapical area, very few report that this complication can be successfully managed with non-surgical endodontic treatment. This case report presents successful management of a lower left second molar (tooth #37) diagnosed with exacerbated chronic apical periodontitis and massive overfill in a 36-year-old patient WITH non-surgical endodontic treatment AND bent H-file to remove extruded material under dental operating microscope control. It discusses technical aspects of this procedure, as well as its possible complications, including a sodium hypochlorite accident.