About a Possible Impact of Endodontic Infections by Fusobacterium nucleatum or Porphyromonas gingivalis on Oral Carcinogenesis: A Literature Overview.

Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis, two bacteria that cause periodontitis, are found in OSCC tissues as well as in oral premalignant lesions, where they exert pro-tumorigenic activities. Since the two bacteria are present also in endodontic diseases, playing a role in their pathogenesis, here we analyze the literature searching for information on the impact that endodontic infection by P. gingivalis or F. nucleatum could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by P. gingivalis and/or F. nucleatum triggers the production of inflammatory cytokines and growth factors in dental pulp cells or periodontal cells, affecting the survival, proliferation, invasion, and differentiation of OSCC cells. In addition, the two bacteria and the cytokines they induce halt the differentiation and stimulate the proliferation and invasion of stem cells populating the dental pulp or the periodontium. Although most of the literature confutes the possibility that bacteria-induced endodontic inflammatory diseases could impact on oral carcinogenesis, the papers we have analyzed and discussed herein recommend further investigations on this topic.

COVID-19 isolation drape for sialendoscopy-assisted transfacial approach to parotid gland.

Surgical procedures requiring close contact with saliva, such as salivary gland surgery, may determine the risk of spreading the SARS-CoV-2 infection. The use of PPE and isolation settings are mandatory to protect health workers.

Is Dental Amalgam a Higher Risk Factor rather than Resin-Based Restorations for Systemic Conditions? A Systematic Review.

OBJECTIVE: The aim of this study was to confirm the hypothesis that patients with one or more amalgam restorations have an increased risk for systemic diseases rather than patients with resin-based restorations. DATA: The data search produced an initial 3568 total number of records. All titles and abstract were reviewed by five independent examiners, and only 36 records were selected for full text in depth examination. Out of these, only nine publications matched the inclusion criteria and were included in this systematic review. SOURCES: Electronic databases (MEDLINE, Scopus, Embase, and Web of Knowledge) were searched up to June 2019. In addition, a manual search was carried out on journals related to this topic. STUDY SELECTION: All selected human clinical studies compared patients with dental amalgam restorations to patients with non-amalgam restorations on restorative material related diseases/health conditions with at least 50 patients and a reasonable follow up. The systemic effects of dental restorations were analyzed. As for any systemic effects, there was no difference between amalgam and composite restoration. CONCLUSIONS: With the limitations of the few available randomized controlled trials (RCTs) on the matter, amalgam restorations, similarly to other modern resin-based materials, were not related to an increased risk of systemic diseases or conditions. CLINICAL SIGNIFICANCE: On the basis of the available RCTs, amalgam restorations, if compared with resin-based fillings, do not show an increased risk for systemic diseases. There is still insufficient evidence to exclude or demonstrate any direct influence on general health. The removal of old amalgam restorations and their substitution with more modern adhesive restorations should be performed only when clinically necessary and not just for material concerns. In order to better evaluate the safety of dental amalgam compared to other more modern restorative materials, further RCTs that consider important parameters such as long and uniform follow up periods, number of restorations per patient, and sample populations representative of chronic or degenerative diseases are needed.

Shaping Ability of Reciproc R25 File and Mtwo System Used in Continuous and Reciprocating Motion.

AIM: Nickel-titanium (NiTi) instruments were designed to be used in continuous rotation mode with controlled speed and torque and a sequence of different sizes. The reciprocating motion was purposed to improve cyclic fatigue of rotary instruments if compared to the conventional rotation. The purpose of this work was to compare the shaping ability of Reciproc R25, Mtwo #25/0.06 used as a single file, and Mtwo sequence used in reciprocating motion and in continuous rotation. MATERIALS AND METHODS: Forty-eight endodontic training resin blocks ISO 15, 2% taper, 7 mm radius, and a 60° angle of curvature were shaped with four different protocols. Group I (Rrsf) was shaped with Reciproc R25 used as a single file in a reciprocating motion. Group II (Mrsf) was shaped with Mtwo #25/0.06 used as a single file in a reciprocating motion. Group III (MSrec) was shaped with Mtwo sequence in reciprocating motion, and finally, group IV (MSrot) was shaped with the Mtwo sequence used in continuous rotation. Preoperative and postoperative images of the simulated canals were taken under standardized conditions and combined exactly. The amount of resin removed was determined at both the inner and outer sides of the canal curvature. The ability of the instruments to remain centered in the canal was determined by calculating a centering ratio. These data were analyzed statistically using two factors analysis of variance (ANOVA) with Bonferroni correction (Bonferroni post-hoc test). RESULTS: Group Rrsf produced a greater enlargement of the canal, especially on the outer side, in the apical and middle third (p < 0.05). Group MSrot produced a lower enlargement in the middle third (p < 0.05). Group Rrsf displayed a lower centering ratio in the apical third (p < 0.05). Group MSrot displayed a lower centering ratio in the coronal third (p < 0.05). CONCLUSION: The shaping of simulated canals using a sequence of instruments in continuous rotation resulted in a more centered preparation of the apical third. The reciprocating motion for all tested instruments produced a bigger enlargement of the canals. CLINICAL SIGNIFICANCE: Reciprocating movement results in a more pronounced canal enlargement but appears to be less respectful of the original canal curvature and produces more apical transportation than a sequence of rotary NiTi files with the same ending apical size.

CAD/CAM Customized Glass Fiber Post and Core With Digital Intraoral Impression: A Case Report.

BACKGROUND: After endodontic treatment, a proper restorative technique is necessary to ensure coronal seal and protection of residual dental structure; teeth which have lost two or more walls need to be restored with posts to increase retention and stability of final restoration. Posts can be distinguished in prefabricated and customized, which are manufactured by lost wax technique or CAD-CAM. PURPOSE: Digital dentistry has been developed to increase workflow precision and to accelerate production process; use of CAD-CAM to realize customized posts was limited to scanning plaster models obtained from traditional impressions. PATIENTS AND METHODS: In the reported case an intraoral scan was used to mill a post and core restoration on an endodontically treated inferior premolar; this operative protocol was based on previous in vitro experiments that confirmed the ability of 3shape Trios scanner to read post-space up to 9 mm in depth. RESULTS: The digital technique allows us to convert the concave surface of the root canal into the convex surface of the post, and realize an anatomical post and core that improves the biomechanics of the endodontically treated tooth reducing the possibility of root fractures. CONCLUSION: The use of an intraoral digital scanner represents an opportunity for the clinician as it speeds up the production of an anatomical post and core restorations.

The relationship of tooth shade and skin tone and its influence on the smile attractiveness.

OBJECTIVE: The purpose of this clinical study was to determine if skin tone and tooth color had the same influence on smile attractiveness. MATERIALS AND METHODS: A woman's smile photograph was digitally manipulated to create a range of images with varying colors. The skin shade was modified to create four tones (p1: light, p2: light medium, p3: medium dark, p4: dark) using the L'Oreal True Illusion shade as a guide. The tooth shade was modified in four different tones: A1, A2, A3, A4 using the VITAPAN Classical shade guide to produce 16 images. A sample of 328 participants rated each image for attractiveness by means of a visual analog scale (VAS). Comparison among groups was performed with a 2-way ANOVA adjusted for multiple comparisons with the Bonferroni test (α = .05). RESULTS: Image (p3-a1) showed the highest VAS values, while image (p1-a4) obtained the lowest, (Bonferroni Test: a1 vs a2, a3, a4 P < .001; p3 vs p1, p2, p4 P < .001). Analysis performed for age, sex, level of education, and laypeople/dentists were not statistically significant (P > .05). CONCLUSIONS: Variations in tooth and skin tone can significantly influence the perception of smile attractiveness. In the tested conditions, a brighter tooth shade significantly affected the attractiveness of the smile independently from skin tone. CLINICAL SIGNIFICANCE: Understanding patient and dentist perception of the attractiveness of a smile with the important role-played by skin tone, may help clinicians to better identify teeth shade, helping delivery of tailored prostheses and esthetic restorations.

Single tooth anesthesia versus conventional anesthesia: a cross-over study.

OBJECTIVES: The aim of the present study was to compare an electronic device, the Wand Injection System (Milestone Scientific Livingstone), with conventional anesthesia in terms of the following: pain sensation during anesthetic injection; effectiveness in achieving adequate anesthesia for a complete painless dental treatment; post-operative discomfort; and patient's anxiety toward dental treatment. MATERIALS AND METHODS: Eighty adults from 18 to 70 years were enrolled in this cross-over study. Each patient served as his/her own control being subject to two anesthesia techniques: conventional and Single Tooth Anesthesia (STA) performed with the Wand. A split-mouth design was adopted in which each tooth undergoing conservative restorative or endodontic treatment received anesthesia with both techniques at 1-week interval. Before anesthetic administration, the patients' anxiety levels were determined. Physiological parameteres were measured before, during, and after the two injection procedures, and the Visual Analogue Scale (VAS) was used to assess pain of injection, discomfort, and anesthetic efficacy. Differences in assessment of pain's injection, discomfort, anesthetic efficacy, vital parameters (heart rate, blood pressure, and oxygen saturation), and state anxiety levels were analyzed using Student's t test (p value < 0.001). RESULTS: The mean injection pain and post-operative discomfort ratings with Wand were lower than those with conventional syringe (p = 0.022 and p < 0.001, respectively). No differences were found in the assessment of anesthetic efficacy. Blood pressure and heart rate mean values were lower during the anesthesia performed with the Wand than with the conventional syringe (p < 0.001). The anxiety level was higher during the first appointment, independently from the device used for the injections. CONCLUSION: The STA technique resulted in lower pain, discomfort, and lower intensity of physiological parameters. CLINICAL RELEVANCE: Single Tooth Anesthesia could be an efficacious alternative to conventional procedures.

Percentage of Gutta-percha-filled Areas in Canals Obturated by 3 Different Techniques with and without the Use of Endodontic Sealer.

INTRODUCTION: This study had 2 purposes: to compare the Microseal, continuous wave, and Thermafil techniques and to compare the same techniques with and without endodontic sealer. METHODS: Ninety extracted mandibular premolars were allocated into 6 groups obturated with Microseal (Analytic, Glendora, CA) and sealer (Mseal), Microseal without sealer (Mnoseal), System B (EIE Analytic Technology, Orange, CA) and sealer (SBseal), System B without sealer (SBnoseal), Thermafil (Dentsply, Tulsa Dental, Tulsa, OK) and sealer (Tseal), and (Tnoseal) Thermafil without sealer (Tnoseal). The teeth were sectioned at 1 and 3 mm from the apex. The total area of each canal segment was measured, and the areas were converted to the percentage of gutta-percha-filled areas, sealer-filled areas, and void areas. Data obtained were statistically elaborated using the t test (P ≤ .01). RESULTS: At 1 mm, SBseal produced a higher VA than Mseal and Tseal. At 3 mm, Tseal produced a lower VA than Mseal and SBseal, whereas Mseal produced a lower VA than SBseal (P > .01). At 1 mm, Tnoseal produced a significantly higher VA than Mnoseal and SBnoseal (P = .001). At 3 mm, Tnoseal produced a higher VA than Mnoseal and SBnoseal (P = .01). Tnoseal produced a significantly higher VA than Tseal both at 1 mm (P = .001) and 3 mm (P = .001). CONCLUSIONS: Endodontic space filling is traditionally provided by sealer and gutta-percha. In this study's conditions, gutta-percha alone showed better filling at both 3 mm and 1 mm in the Microseal and System B techniques. Considering the limits of our study, we can affirm that endodontic techniques using sealer could counteract thermoplasticized gutta-percha progression.

Embryotoxicity assays for leached components from dental restorative materials.

BACKGROUND: Currently, there are no suitable assays available to evaluate the embryotoxicity of leached components from restorative dental materials. METHODS: The effect of the medium conditioned by composites and amalgam on mouse blastocysts in vitro was tested. The materials were also subcutaneously implanted, and the effect of the medium supplemented with serum from the host blood was evaluated in the embryotoxicity assay. The embryo implantation rate in the material-transplanted mothers was also evaluated. RESULTS: The results show that while the culture in media conditioned by amalgams did not affect blastocyst development, the medium conditioned by composites caused blastocyst degeneration and apoptosis. The development of blastocysts in a medium containing serum obtained from animals after transplantation was, however, without effect. Finally, inconsistent reduction in the implantation rate in transplanted mothers was observed. CONCLUSIONS: In this study, we provide examples of in vitro and in vivo tests that may be used to evaluate embryotoxicity for dental materials. Our results show that leached components from our composite-material induced embryotoxicity in vitro, however, no toxicity was observed when subcutaneously implanted in vivo. This highlights the necessity of integrated in vitro and in vivo tests for valuable predictive estimation of embryotoxicity for complex materials.