Metastases of OSCC Based on Oral Lichen Ruber Planus.

Oral lichen ruber planus (OLP) is a poorly understood chronically inflammatory disease of the oral mucosa. Malignant transformation into oral squamous cell carcinoma (OSCC) is reported in between 1-2% of cases in the literature. After malignant transformation, surgical treatment-meaning tumor resection combined with neck dissection-is recommended. The recommended extent of treatment is controversial in the literature because this kind of OSCC is often a highly differentiated tumor with a lower risk for lymph nodal spreading. This study aims to overview 103 patients treated in our department due to OLP. The primary outcome parameter was the development of metastases in OLP patients compared to a group of OSCC patients without OLP and the comparison of survival in between both groups. Statistical analysis showed a significantly lower risk for patients with OSCC and with OLP for lymph nodal spreading (p = 0.013). Patients with OSCC and without OLP had a 4.76-higher risk for lymph nodal spreading. On the other hand, second metachronous tumor occurred more often in patients with OSCC and OLP. Overall, OSCC based on OLP occurs more often in female patients, is more highly differentiated and comes with a lower risk for metastases but has a higher risk for second metachronous tumors. Therefore, special attention should be paid to patients with OSCC based on OLP when planning adjuvant therapy and clinical follow-up. The indication for postoperative radiation should be made cautiously in this case, and clinical controls should be performed more closely due to the risk of recurrent disease or tumors at different locations.

Leaching components and initial biocompatibility of novel bioactive restorative materials.

OBJECTIVES: Bioactive restorative materials were developed on the premise that direct restorations should not only serve the purpose of reconstructing dental hard tissue defects but also exhibit biological features that prevent secondary caries development, without having adverse effects on the host cells. This study focuses on assessing the in vitro biocompatibility of two novel bioactive restorative materials. METHODS: Specimens of the bioactive restorative materials, Cention Forte (CF) and ACTIVA BioACTIVE RESTORATIVE (AB), a glass ionomer cement/glass hybrid (EQUIA Forte HT, EF) and an established nanohybrid composite (Venus Diamond, VD) were produced and finished. The specimens were eluted in water and methanol and the resulting eluates were analyzed via gas chromatography-mass spectrometry. hGF-1 cells were exposed to eluates prepared in cell culture medium. Cellular ATP levels, oxidized glutathione concentration, caspase-3/7 activity and the inflammatory response (IL-6 and PGE2 levels) were determined. Microscopic images were taken to examine the cell morphology. RESULTS: Methyl methacrylate and 2-Hydroxyethyl methacrylate were the main monomers detected in CF and AB eluates. All materials inhibited cell proliferation and led to significantly reduced ATP-levels. The cells exhibited a healthy morphology in the presence of CF and AB. Cells exposed to VD showed increased oxidized glutathione levels. Only EF led to enhanced caspase-3/7 activity. CF and AB caused IL-6 levels to increase, while EF and AB led to enhanced PGE2 levels. SIGNIFICANCE: CF and AB are promising materials from a biological point of view and seem to have improved bioactive properties compared to glass ionomer cements.

E-scooter-related craniomaxillofacial injuries compared with bicycle-related injuries - A retrospective study.

The aim of the study was to compare incidences and types of injury incurred between e-scooter crashes and bicycle crashes. This retrospective study included all victims of e-scooter crashes who were treated in the department of oral and maxillofacial surgery during a 12-months interval.A comparison was made with a cohort of patients who underwent bicycle crashes. Study parameters included type of fracture, soft tissue and dental affection, necessity of inpatient or outpatient treatment, the use of helmets, and the time of admission. In total, 400 patients were included. Of these 40 had suffered a crash on an e-scooter and 360 on a bicycle. Descriptive statistics showed a low helmet-wearing rate among cyclists (16.1% of recorded cases), with no helmet wearing recorded among e-scooter users. E-scooter-related crashes showed a higher rate of facial soft-tissue injuries (77.5%, p = 0.049) than among cyclists (61.7%), as well as a higher rate of dental injuries (27.5%, p = 0.017) compared with the bicycle cohort (13.3%). Facial fractures were also more common in the e-scooter cohort (45% vs 25.8%, p = 0.010). Admission was typically at the weekend - in the afternoon for the bicycle cohort and in the evening and at night for the e-scooter cohort. As a consequence of the fact that e-scooter riders seem to have an increased risk of facial injuries, it seems that an awareness campaign might be necessary to encourage helmet usage and to persuade intoxicated persons to use public transportation instead.

Initial biocompatibility of novel resins for 3D printed fixed dental prostheses.

OBJECTIVES: Several materials for 3D printing of fixed dental prostheses (FDP) have been recently introduced. This study aims to evaluate the initial biocompatibility of novel printable resins for manufacturing temporary and permanent FDP. METHODS: Specimens of five printable resins (VarseoSmile Crown plus, NextDent C&B MFH, VarseoSmile Temp, Temp PRINT, P Pro Crown & Bridge), two types of resins for subtractive manufacturing (Tetric CAD, Telio CAD) and two types of resins with conventional curing processes (Tetric EvoCeram, Protemp 4) were produced and finished. Post-processing was strictly performed according to the manufacturer's protocol. Biocompatibility was evaluated by eluting specimens with cell culture medium and treating human gingival fibroblast cells with the eluates. A 72-hour continuous read cell viability assay measuring the reducing potential of the cells was performed. The cellular inflammatory response in terms of IL-6 and PGE2 levels was determined with specific ELISAs. Oxidative stress was determined by measuring oxidized glutathione concentrations after exposure to the resin eluates. A luminescence-based apoptosis assay was used to detect apoptosis. RESULTS: Tetric CAD and Telio CAD were slightly toxic. All other resins were moderately to severely cytotoxic. VarseoSmile Crown plus and P Pro Crown & Bridge significantly enhanced PGE2 levels. Higher concentrations of oxidized gluthatione were determined in the presence of Telio CAD, VarseoSmile Temp and P Pro Crown & Bridge. Tetric EvoCeram and Protemp 4 reduced intracellular gluthatione levels. All printable resins slightly induced apoptosis. SIGNIFICANCE: Further post-processing steps such as additional curing and washing may improve the biocompatibility of printable materials.

A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers.

OBJECTIVES: To evaluate the biological and physicochemical features of bioactive root canal sealers. MATERIALS AND METHODS: Human periodontal ligament fibroblasts (hPDLF) and human osteoblasts (hOB) were exposed to eluates of three bioactive root canal sealers, GuttaFlow® bioseal (GF), BioRoot™ RCS (BR), and TotalFill® BC Sealer (TF), and the epoxy resin-based sealer AH plus® (AH). Cytotoxicity and cellular inflammatory response were evaluated. The osteogenic potential was examined using human mesenchymal stem cells (hMSC). Film thickness, flowability, and pH were assessed. Root canal treatment was performed on human extracted teeth to evaluate the sealers' tightness towards bacterial penetration. The antibacterial activity against common pathogens in primary root canal infections was tested. RESULTS: AH was severely cytotoxic to hPDLF and hOB (p < 0.001). The bioactive sealers were generally less cytotoxic. IL-6 levels in hPDLF were elevated in the presence of AH (p < 0.05). AH and GF suppressed IL-6 production in hOB (p < 0.05). AH and BR stimulated the PGE2 production in hPDLF and hOB (p < 0.05). BR was the only sealer that led to calcium deposits in hMSC (p < 0.05). TF and AH showed the lowest film thickness and the highest flowability. Bacterial tightness was best in teeth filled with AH and BR. All sealers showed similar antimicrobial activity, but the overall antimicrobial efficacy was moderate as the bacteria were reduced by just one log scale (p < 0.05). CONCLUSIONS: This study revealed favorable in vitro results regarding the biocompatibility of the bioactive root canal sealers. CLINICAL RELEVANCE: Bioactive root canal sealers may be a useful alternative to epoxy resin-based sealers.

First comparison of a new dynamic navigation system and surgical guides for implantology: an in vitro study.

AIM: The transfer of 3D implant position planning to the clinical site is challenging. The aim of this study was to compare in vitro this transfer accuracy by using dynamic real-time navigation or static surgical guides. MATERIALS AND METHODS: Deviations between planned and actual pilot drill positions were calculated (Denacam and NobelGuide; each n = 90), matching pre- and postoperative CBCT images: entry point, angle, tip (each 3D); depth, mesiodistal/bucco-oral entry points, and angles (each 1D). The influence of the maxilla and mandible, implant region (anterior/posterior), and marker position (ipsilateral/contralateral, Denacam only) was investigated (Mann-Whitney U test). RESULTS: No significant differences occurred regarding entry point (3D), mesiodistal/bucco-oral entry points (1D) or mesiodistal angle (1D) (P > 0.05). The angular and tip deviations (3D) were significantly smaller using Denacam (2.16 ± 0.59 degrees, 0.80 ± 0.55 mm; NobelGuide 2.54 ± 1.19 degrees, 1.09 ± 0.56 mm; P = 0.024, P < 0.0001). The deviations in depth and bucco-oral angle (1D) were significantly smaller using NobelGuide (1.05 ± 0.50 mm, 1.02 ± 1.16 degrees; Denacam 1.50 ± 0.64 mm, 1.51 ± 0.82 degrees; P < 0.0001). Significantly smaller deviations occurred within the mandible (Denacam, 5/8 parameters). Region and marker position showed no influence. No distinct influences were found with the use of NobelGuide. CONCLUSION: Denacam might possibly be a promising alternative to static surgical guides.

Fracture load and chewing simulation of zirconia and stainless-steel crowns for primary molars.

Aesthetic alternatives to stainless-steel crowns for restoring primary molars attain growing interest. We studied the mechanical properties of prefabricated zirconia crowns and conventional crowns. Three brands of prefabricated zirconia crowns were compared with computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crowns, preveneered stainless-steel crowns, and conventional stainless-steel crowns regarding: (i) fracture load under each of three conditions [no pretreatment, artificial aging in saliva for 12 wk, and after chewing simulation/thermocycling (1.68 × 106 cycles/5-55°C)]; and (ii) survival rate during chewing simulation, considering decementation, fracture, chipping, fatigue cracks, and occlusal holes. Without pretreatment, the prefabricated zirconia crowns showed mean fracture load values between 893 N and 1,582 N, while the corresponding values for CAD/CAM zirconia crowns and preveneered stainless-steel crowns were 2,444 N and 6,251 N. Preveneered stainless-steel crowns showed significantly lower fracture loads after artificial aging (5,348 N after saliva aging; 3,778 N after chewing simulation) than without artificial aging, whereas the fracture load of zirconia crowns was not influenced negatively. The survival rate of the different groups of zirconia crowns and preveneered stainless-steel crowns during chewing simulation was 100%, but only 41.7% for the stainless-steel crowns. These in-vitro data suggest that prefabricated zirconia crowns are aesthetically and durable alternatives to stainless-steel crowns for primary molars.

Comparison of ozone gas and sodium hypochlorite/chlorhexidine two-visit disinfection protocols in treating apical periodontitis: a randomized controlled clinical trial.

OBJECTIVES: In this single-blinded, prospective, randomized, controlled clinical trial, the effectiveness of an ozone gas or NaOCl/CHX disinfection protocol was compared within the root canal treatment of apical periodontitis. MATERIALS AND METHODS: Sixty permanent teeth were randomly allocated to one technique. The clinical/radiographic assessment criteria included clinical symptoms, periapical index (PAI), and size of the apical lesion. In both groups, the root canal was mechanically cleaned and irrigated with NaCl and EDTA. Ozone gas (32 g m-3) or NaOCl (3 %) was applied followed by a 1-week inter-appointment dressing (Ca(OH)2). As final disinfection, ozone gas (ozone group) or CHX 2 % (NaOCl group) was applied. Microbial samples were taken after preparing the access cavity, after chemo-mechanical treatment and after inter-appointment dressing by sterile paper points. Microbial identification was performed by mass spectroscopy (MALDI-TOF-MS) and 16S-rRNA gene sequencing. The treated teeth were blindly re-evaluated after 6/12 months. Success rates, the decrease in PAI, the size of apical lesions and bacterial reduction were compared between groups (Fischer's exact test, Mann-Whitney U test). RESULTS: There were no significant differences between the success rates (ozone group: 96.2/95.5 % after 6/12 months; NaOCl group: 95.5/95.2 % after 6/12 months). The differences in the decreases in PAI values and apical lesion sizes were also insignificant after 6 and 12 months. The bacterial reduction showed no significant differences between groups after chemo-mechanical treatment and after inter-appointment dressing. The most commonly found bacterial genera were Streptococcus spp., Parvimonas spp. and Prevotella spp. CONCLUSIONS: The here used ozone gas and NaOCl/CHX protocols showed no difference in bacterial reduction in the sampled areas of the root canals. CLINICAL RELEVANCE: Within the limitations of the study, ozone gas seems to be a possible alternative disinfection agent within the root canal treatment of apical periodontitis.