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Gandolfi MG, Taddei P, Siboni F, Modena E, Ginebra MP, Prati C. Fluoride-containing nanoporous calcium-silicate MTA cements for endodontics and oral surgery: early fluorapatite formation in a phosphate-containing solution. International Endodontic Journal, 44, 938–949, 2011. Aim To test the chemical–physical properties and apatite-forming ability of experimental fluoride-doped calcium silicate cements designed to create novel bioactive materials for use in endodontics and oral surgery. Methodology A thermally treated calcium silicate cement (wTC) containing CaCl2 5%wt was modified by adding NaF 1%wt (FTC) or 10%wt (F10TC). Cements were analysed by environmental scanning electron microscopy with energy-dispersive X-ray analysis, IR and micro-Raman spectroscopy in wet conditions immediately after preparation or after ageing in a phosphate-containing solution (Dulbecco’s phosphatebuffered saline). Calcium and fluoride release and pH of the storage solution were measured. The results obtained were analysed statistically (Tukey’s HSD test and two-way anova). Results The formation of calcium phosphate precipitates (spherulites) was observed on the surface of 24 h-aged cements and the formation of a thick bone-like B-type carbonated apatite layer (biocoating) on 28 day-aged cements. The rate of apatite formation was FTC > F10TC > wTC. Fluorapatite was detected on FTC and F10TC after 1 day of ageing, with a higher fluoride content on F10TC. All the cements released calcium ions. At 5 and 24 h, the wTC had the significantly highest calcium release (P < 0.001) that decreased significantly over the storage time. At 3–28 days, FTC and F10TC had significantly higher calcium release than wTC (P < 0.05). The F10TC had the significantly highest fluoride release at all times (P < 0.01) that decreased significantly over storage time. No significant differences were observed between FTC and wTC. All the cements had a strong alkalinizing activity (OH) release) that remained after 28 days of storage. Conclusions The addition of sodium fluoride accelerated apatite formation on calcium silicate cements. Fluoride-doped calcium silicate cements had higher bioactivity and earlier formation of fluorapatite. Sodium fluoride may be introduced in the formulation of mineral trioxide aggregate cements to enhance their biological behaviour. F-doped calcium silicate cements are promising bone cements for clinical endodontic use.

Background: Recently several calcium silicate flowable sealers have been introduced as endodontic materials for the root canal. This clinical study tested the use of a new premixed calcium silicate bioceramic sealer in association with the Thermafil warm carrier-based technique (TF). Epoxy-resin-based sealer with the warm carrier-based technique was the control group. Methodology: Healthy consecutive patients (n = 85) requiring 94 root canal treatments were enrolled in this study and assigned to one filling group (Ceraseal-TF n = 47, AH Plus-TF n = 47) in accordance with operator training and best clinical practice. Periapical X-rays were taken preoperatively, after root canal filling and after 6, 12 and 24 months. Two evaluators blindly assessed the periapical index (PAI) and sealer extrusion in the groups (k = 0.90). Healing rate and survival rate were also evaluated. Chi-square tests was used to analyze significant differences between the groups. Multilevel analysis was performed to evaluate the factors associated with healing status. Results: A total of 89 root canal treatments in 82 patients were analyzed at the end-line (24 months). The total drop-out was 3.6% (3 patients; 5 teeth). A total of 91.1% of healed teeth (PAI 1-2) was observed in Ceraseal-TF, with 88.6% in AH Plus-TF. No significant difference was observed on healing outcome and survival among the two filling groups (p > 0.05). Apical extrusion of the sealers occurred in 17 cases (19.0%). Of these, 6 occurred in Ceraseal-TF (13.3%) and 11 in AH Plus-TF (25.0%). Three Ceraseal extrusions were radiographically undetectable after 24 months. All the AH Plus extrusions did not change during the evaluation time. Conclusions: The combined use of the carrier-based technique and premixed CaSi-based bioceramic sealer showed clinical results comparable with carrier-based technique and epoxy-resin-based sealer. The radiographical disappearance of apically extruded Ceraseal is a possible event in the first 24 months.

This study aimed to characterize the chemical properties and bioactivity of an endodontic sealer (GuttaFlow Bioseal) based on polydimethylsiloxane (PDMS) and containing a calcium bioglass as a doping agent. Commercial PDMS-based cement free from calcium bioglass (GuttaFlow 2 and RoekoSeal) were characterized for comparison as well as GuttaFlow 2 doped with dicalcium phosphate dihydrate, hydroxyapatite, or a tricalcium silicate-based cement. IR and Raman analyses were performed on fresh materials as well as after aging tests in Hank’s Balanced Salt Solution (28 d, 37 °C). Under these conditions, the strengthening of the 970 cm−1 Raman band and the appearance of the IR components at 1455–1414, 1015, 868, and 600–559 cm−1 revealed the deposition of B-type carbonated apatite. The Raman I970/I638 and IR A1010/A1258 ratios (markers of apatite-forming ability) showed that bioactivity decreased along with the series: GuttaFlow Bioseal > GuttaFlow 2 > RoekoSeal. The PDMS matrix played a relevant role in bioactivity; in GuttaFlow 2, the crosslinking degree was favorable for Ca2+ adsorption/complexation and the formation of a thin calcium phosphate layer. In the less crosslinked RoekoSeal, such processes did not occur. The doped cements showed bioactivity higher than GuttaFlow 2, suggesting that the particles of the mineralizing agents are spontaneously exposed on the cement surface, although the hydrophobicity of the PDMS matrix slowed down apatite deposition. Relevant properties in the endodontic practice (i.e., setting time, radiopacity, apatite-forming ability) were related to material composition and the crosslinking degree.

Purpose:This 3-year study aimed to evaluate hard and soft tissue modification around a two-piece implant characterized by a transmucosal hyperbolic neck in healthy consecutive patients with a need for single-tooth replacement. Materials and Methods: Two-piece implants (n = 66) were placed with a flapless technique in 56 patients (27 men; 29 women; mean age 55 ± 9 years): 16 immediately after root extraction (immediate group), 20 after 8 to 12 weeks (early group), and 30 after 10 or more months (delayed group). The transmucosal hyperbolic neck was exposed 1 to 1.5 mm above gingival level. Customized abutments were positioned 3 months later with the implant-abutment connection located approximately 1 to 1.5 mm above soft tissue level. Provisional cemented resin crowns were designed with the finishing line at the hyperbolic neck and then positioned to avoid excessive compression of soft tissue, to guide gingival contours. Twenty days later, a definitive metal-ceramic crown was cemented. In all patients, the gingival biotype (thin or thick) was also evaluated. The primary outcomes were as follows: 36-month implant survival rate, peri-implant marginal bone level (MBL, in mm) changes observed in single-blind on radiographs at 1, 3, 6, 12, 24, and 36 months (T1, T3, T6, T12, T24, and T36), and pink esthetic score (PES) at T6, T12, and T36 to analyze soft tissue adaptation after loading and crown application. The secondary outcomes were as follows: plaque score and bleeding on probing (BOP). Linear regression models and multilevel mixed logistic regression were used to detect any statistical difference of MBL according to operative parameters. Kruskal-Wallis one-way analysis of variance (ANOVA) on ranks was performed to assess statistical differences of PES at T6, T12, and T36. Results: The survival rate was 100%. The dropout rate was 1.79%. No infections, mucositis, or peri-implantitis were reported. Implants placed in thick-biotype tissues showed a statistically different lower bone loss at 36 months with respect to the thin biotype (P

Purpose: To examine the microscopic surface features, chemical composition, and thermodynamic profile of seven endodontic sealers (AH Plus, Adseal, MTA-Fillapex, RoekoSeal, GuttaFlow 2, GuttaFlow BioSeal, and EndoRez) exposed to high-temperature changes using an endodontic obturation device. Methods: The thermal properties were examined using scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Then, six disc-shaped specimens of each sealer were prepared and divided into two groups – a room temperature group and a heat exposure group – for analysis of surface and chemical changes using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Results: DSC analysis showed that AH Plus had the highest exothermal signal (122.9°C), while TGA analysis showed that MTA-Fillapex was most affected by increased temperature (32.4% mass loss at 230ºC). SEM analysis showed that while AH Plus and GuttaFlow BioSeal maintained their surface integrity after heat exposure, the EDS profiles demonstrated changes in the chemical composition of the sealers after heat exposure for 5 s. High-temperature exposure had a negative impact on the properties of five of the sealers (Adseal, MTA-Fillapex, RoekoSeal, GuttaFlow 2, and EndoRez). Conclusion: AH Plus and GuttaFlow BioSeal showed minimal changes upon high-temperature exposure, suggesting their suitability for thermal endodontic obturation techniques. Universidad de Costa Rica/[816-B8-279]/UCR/Costa Rica UCR::Vicerrectoría de Docencia::Salud::Facultad de Odontología

Dental professionals often perform physically and mentally demanding therapeutical procedures. They work maintaining muscular imbalance and asymmetrical positions for a long time. The aim of the study was to describe the prevalence and the factors associated to work-related musculoskeletal disorders (WMSD) among Italian dental professionals and the most affected body regions. A cross-sectional observational study was conducted between March 2019 and February 2020. The Nordic Musculoskeletal questionnaire (NMQ) was implemented with questions related to working habits (dental occupation, working hours per week and per days, years of work) and lifestyle (practiced physical activity, including frequency and duration, mobilization activities, and knowledge of ergonomic guidelines) was used. The-chi square test was carried out to detect any statistically significant difference (p &lt, 0.05). Logistic regression was carried out to detect the most significant factors associated to WMSD occurrence. A total of 284 questionnaires have been used for the analysis. A high proportion of dental professionals (84.6%) were affected by WMSD in the last 12 months. A higher prevalence was found in females (87%) when compared to males (80%). The prevalence of WMSD was correlated to the working hours/day and hour/week, with a higher risk for operators working &gt, 5 h/day and &gt, 30 h/week. In addition, a high prevalence was found in operators working for 2–5 years after graduation. Most of the surveyed dental professionals practiced physical activity (70.1%) but only a few had satisfactorily knowledge of ergonomic guidelines (12.7%). Interestingly, participants who practiced yoga or stretching as physical activities demonstrated lower WMSD (77%) when compared to other physical activities (84%). We can highlight that generic physical activities have no functional effect on WMSD for dental professionals. The most affected body areas were neck (59.9%), shoulders (43.3%), lumbar region (52.1%), dorsal region (37.7%) and wrists (30.6%). Considering the magnitude of the problem, there is an urgent need to implement the education in ergonomics among dental professionals, that may be achieved by teaching biomechanics, posturology and integrative functional therapies (such as yoga) during the university education and by promoting holistic health of dental operators.

Tissue regeneration in dentistry has demonstrated impressive progress over during the last decades compared to other medical sciences [...]

Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur through saliva and aerosol droplets deriving from the upper aerodigestive tract during coughing, sneezing, talking, and even during oral inspection or dental procedures. The aim of this study was to assess in vitro virucidal activity of commercial and experimental mouthwashes against a feline coronavirus (FCoV) strain. Commercial and experimental (commercial-based products with addition of either sodium dodecyl sulfate (SDS) or thymus vulgaris essential oil (TEO) at different concentrations) mouthwashes were placed in contact with FCoV for different time intervals, that is, 30s (T30), 60s (T60), and 180s (T180); subsequently, the virus was titrated on Crandell Reese Feline Kidney cells. An SDS-based commercial mouthwash reduced the viral load by 5log10 tissue culture infectious dose (TCID)50/50µl at T30 while a cetylpyridinium (CPC)-based commercial mouthwash was able to reduce the viral titer of 4.75log10 at T60. Furthermore, five experimental mouthwashes supplemented with SDS reduced the viral titer by 4.75–5log10 according to a dose- (up to 4mM) and time-dependent fashion.

OBJECTIVES The purpose of this Module is to critically describe the evolution of endodontic instrumentation techniques and of rotary and reciprocating instruments to identify their clinical advantages and limitations in the clinical practice. Morphological aspects, importance of bacteria contamination and other clinical aspects are described and discussed. MATERIALS AND METHODS All concepts and techniques described in this didactic Module are supported by an extensive analysis of the literature ranging from in vitro studies on the mechanics of movements to the microscopic analysis of alloys, passing through long-term clinical and microbiological studies on various endodontic instrumentation techniques. The most recent technological innovations in the endodontic field were subsequently analyzed. In particular, the application of heat treatment to rotary instruments has led to a significant reduction in the risk of fracture, even in the presence of canals with severe curvatures with mineralized or sclerotic dentin. The development and introduction of the reciprocating movement applied to NiTi instruments allowed a reduction in the operating sequences and it is proposed as a single-instrument technique. Different instrumentation techniques will be described, analyzed step by step and correlated according to the present clinical situation. In association with the instruments, some of the main endodontic motors that introduce torque and reverse function will be analyzed in order to control the speed and mechanical stress of the instrument, to prevent instrument fracture and to facilitate the operator in clinical practice. The authors will describe several clinical tech niques and the use of different instruments. RESULTS The first NiTi instruments, marketed around 25-30 years ago, presented only austenitic phase at room temperature. These instruments were rigid and presented a high risk of fracture. More recently, rotary NiTi instruments characterized of thermal or chemical treatment have been introduced, with presence of austenitic, martensitic and R phase at room temperature. These instruments have greater resistance, deformability, flexibility and shape memory, allowing their use in preparation of curved and complex endodontic canals reducing significantly the risk for fracture. The reciprocating movement is introduced in clinical practice with specific motors. The technique offer the possibility to prepare root canals with simple and moderately curved morphology. CONCLUSIONS The described techniques, per formed with heat treated rotating and reciprocating NiTi instruments, allow to approach to both simple and complex root canals with a lower risk of instrument fractures. The use of such complex endodontic techniques in complex anatomy canals is only possible after an adequate training of the operators to prevent any clinical error and fracture of the instrument. CLINICAL SIGNIFICANCE The use of the most suitable preparation technique allows to perform root canal treatment with greater safety and minor risks for intra-operative complications.

OBJECTIVES Endodontic retreatment procedures are increasing in clinical practice. The re-treatment aims to maintain a previous-ly treated tooth in which a periapical lesion is detected. Retreatment procedures should remove the previous filling material, provide an effective instrumentation and irrigation of the canal and provide a stable obturation and tooth reconstruction. These procedures are often complex and time consuming. The purpose of this Module is to describe the current endodontic retreat-ment techniques trying to identify their advantages and clinical limitations. MATERIALS AND METHODS The main causes of endodontic retreat-ment are considered, through the de-scription of the endodontic microbiolo-gy and the types of periapical lesions that can be observed in non-healed root canal treatments. The morphology of the endodontic canal after second instrumentation is described and some strategies are considered to remove the old filling material. RESULTS The conditions of endodontic retreat-ment are mainly due to the reinfection of the endodontic space, which can oc-cur due to coronal contamination (loss of the coronal seal) or to the presence of bacterial populations in areas of the canal not instrumented. Some bacteria, such as Treponema denticola and Por-phiromonas gingivalis, are highly pathogenic and are able to systemical-ly spread and reach different anatomi-cal districts, such as the heart, spleen, liver, and brain. One of the main problems of retreat-ment techniques is the possibility of pushing the infected debris of the ma-terial contained in the canal beyond the apex. These infected debris are respon-sible for acute post-operative pain and acute inflammatory phenomena. Ultrasonic instruments can support traditional manual instrumentation techniques and enhance the effect of the ir-rigants. Reciprocating instrumentation techniques can be used in the removal of the obturation material and in the instrumentation of the root canal. Secondary treatment can be surgically performed (endodontic surgery) where coronal access to the endodontic system is not feasible. Endodontic surgery shows high long-term success and survival rates in recent studies. CONCLUSIONS Endodontic retreatment still remains a complex and time consuming tech-nique. The use of ultrasonic instrumen-tation and reciprocating techniques al-low for better removal of the obturation material and a more effective instru-mentation of the canal. Retrograde endodontic surgery is a useful technique for maintaining the endodontical-ly treated element. CLINICAL SIGNIFICANCE The identification of a new periapical lesion, the non-healing and its exacer-bation in an endodontically treated element is attributable to the non-eradica-tion of pathogenic bacteria, or to a new reinfection of the canal space. For this reason, material removal, irrigation and instrumentation techniques play an important role in endodontic retreatment.

OBJECTIVES The aim of this didactic module is to describe the main root canal obturation techniques, the biomaterials used, their applications, limits and advantages. MATERIALS AND METHODS The main root canal obturation techniques are described, with particular attention to the scientific evidence, the clinical evaluation and some historical aspects. Biomaterials to seal the root canal are examined, describing their chemical physical and biological properties, such as the setting time and expansion, radiopacity, biointeractivity and bioactivity. RESULTS Root canal obturation must avoid the bacteria recolonization of previously instrumented root canal and prevent the contamination of the periapical bone. The filling material should provide a stable tridimensional seal of the end odontic space with no voids or gaps at the root canal-material interface. The materials must also be insoluble, radiopaque, biocompatible and non-toxic. The techniques and the materials should be easy to be used in complex cases and non-operator dependent. Classical root canal techniques, such as cold lateral compaction and warm vertical compaction demonstrated valid results in long term studies, when associated to gutta-percha and traditional sealers. Carrier-based techniques, developed 30 years ago, showed extremely predictable results, which may be attributable to their simple procedure. For this reason, carrier-based is considered one of the gold standard techniques nowadays. All the techniques necessitate of a sealers. The sealers are used to occupy the small porosities and filling defects, aiming to guarantee the long-term sta bility of root canal treatment. Traditional zinc oxide-eugenol cements and epoxy resin based sealers have been used for years with excellent clinical results documented in literature. Bioceramic calcium silicate based cements are a group of materials from MTA initially used for retrograde obturation during root-end surgery. Bioceramics have innovative properties such as excellent biocompatibility, the ability to set in presence of moisture, the ability to expand and to nucleate apatite. Cold filling techniques, such as single-cone and lateral compaction, are recommended for these cements. Their principal clinical applications are elements with perforations or canal aberrations, wide apexes, large periapical bone defects and infected root canals. CONCLUSIONS Several materials are now clinically available. Knowledge and proficiency of both materials and technique is import ant in clinical practice. Coronal obturation and post-endodontic rehabilitation is crucial to prevent reinfection of the root canal over time. CLINICAL SIGNIFICANCE The evolution of cements, with the introduction of calcium-releasing bioceramics, represent a further step towards a more predictable endodontics using osteoinductive and osteoconductive materials. Biomaterials knowledge, and the proficiency of the operator in root canal obturation techniques are important aspects to obtain excellent and long-term clinical results.

OBJECTIVES The main objective of this Module is to describe the factors to be clinically evaluated in presence of a tooth with uncertain prognosis, i.e. when it is better to keep and retreat a previously root canal treated tooth or when to extract it and replace with an implant rehabilitation. Such situation and the decision making regarding techniques and operative procedures has become extremely frequent in daily routine. MATERIALS AND METHODS The main clinical studies that examined root canal retreatment and implant rehabilitation outcome were re ported and discussed. The main ana tomical, endodontic and prosthetic variables of these compromised teeth were analyzed and the decision mak ing approach were discussed. RESULTS Teeth affected by endodontic pathology are frequently associated to massive loss of enamel and dentin tissues. Their rehabilitation represents a hard challenge for clinicians. The compromised teeth can be endodontically retreated (secondary treatment). Unfortunately, their morphology and tissue alteration may be responsible for root fractures, root resorption and cervical decays, with an uncertain prognosis and success rate. Furthermore, retreatment pro cedures for compromised teeth re quire long working times and specific skills in endodontics practice, con servative dentistry, dental prosthesis and periodontology. For patients without medical risks and/or systemic pathologies, another clinical approach for endodontically treated compromised teeth can be the extraction and subsequent insertion of a dental implant and prosthetic rehabilitation (post-endodontic implant). Post-endodontic implants must be placed after some months from extraction in healthy mature bone (delayed implants), or immediately inserted after extraction (post-extractive implants). Hopeless seriously damaged teeth free from periapical lesions or affected by chronic periapical disease without signs and symptoms can be approached with post-extractive implants with advantage of reduced pro cedures. On the contrary, hopeless endodontically treated teeth affected by acute and symptomatic periapical lesions may be extracted and replaced only after healing and bone regeneration. Methods to prevent bone defect and reabsorption may be considered in the decision making. Infected apical sites are responsible for higher risk of no-osteointegration and potential implant failure. CONCLUSIONS Specialists in endodontics should know implantology because it represents an effective alternative to retreatment procedures for compro mised hopeless teeth in patients with out medical risks. A carefull and well-programmed implant may result in a more predictable and higher success rates than a complex and high risk endodontic treatment of teeth with large tissue destruction. Like sur gical root-end endodontics, post-end odontic implant placement may repre sent a choice for a high level therapeutic approach. CLINICAL SIGNIFICANCE Endodontists should know limits and advantages of implantology. They must evaluate the adequate surgical proce dures and implant insertion timing related to specific clinical situation. Finally, the endodontists must know the management of soft and hard tissues after tooth extraction and implant insertion.

Dental-care workers operate very close to the patient&rsquo, s mouth and are at high risk of contamination by SARS-CoV-2. Droplets may be contaminated by patient&rsquo, s saliva and exhaled breath particles. All asymptomatic patients should be considered as Coronavirus positive. All dental procedures must be revised after positive identification of SARS-Cov-2. Novel recommendations as the use of novel suction cannula designed for fast spray/saliva aspiration, use of Tyvek suits and innovative sprayhoods designed for dental-care worker protections are proposed to prevent virus transmission. New tailored operative and clinical procedures are being currently developed by university dental clinics and hospitals in attempt to reduce risk for dental workers and patients.

Zygomatic implant rehabilitation is a challenging procedure that requires an accurate prosthetic and implant plan. The aim of this study was to evaluate the malar bone available for three-dimensional zygomatic implant placement on the possible trajectories exhibiting optimal occlusal emergence. After a preliminary analysis on 30 computed tomography (CT) scans of dentate patients to identify the ideal implant emergencies, we used 80 CT scans of edentulous patients to create two sagittal planes representing the possible trajectories of the anterior and posterior zygomatic implants. These planes were rotated clockwise on the ideal emergence points and three different hypothetical implant trajectories per zygoma were drawn for each slice. Then, the engageable malar bone and intra- and extra-sinus paths were measured. It was possible to identify the ideal implant emergences via anatomical landmarks with a high predictability. Significant differences were evident between males and females, between implants featuring anterior and those featuring posterior emergences, and between the different trajectories. The use of internal trajectories provided better bone engagement but required a higher intra-sinus path. A significant association was found between higher intra-sinus paths and lower crestal bone heights.

Aim: This 60-month prospective study aimed to evaluate tooth survival and healing rates after root canal treatment in patients taking bisphosphonates (BPs). Secondary outcomes were complications and clinical variables observed during and after treatment. Methods: Root canal treatment was performed using manual K-file canal instrumentation and a carrier-based filling technique with an epoxy resin-based sealer. Teeth without adequate root/crown integrity were restored by trained operators at the tissue level (TL group) to prevent occlusal/mechanical stress and to enable periapical lesion healing without the risk of root fracture. Other teeth were restored with normal occlusal contacts (OC group). Healthy patients who had undergone one or more root canal treatments of the same type constituted the control group. The relationships of the following variables to survival and health status were examined (chi-squared test and multivariate analysis, P=0.05): age, gender, smoking habit, tooth location, treatment type, BPs treatment, BPs exposure, initial periapical index (PAI) and occlusal restoration. Survival curves were constructed using Kaplan–Meier analysis, with extraction serving as the end-point. Results: In total, 65 patients with 109 root canal-treated teeth who were taking BPs were included. At 60months, data from 57 patients (52F, 5M; median age 65.7±8.6years) who had undergone 96 root canal treatments were analysed (drop-out rate=16.9%). The survival rate was 85%, and the success rate was 76%. The control group consisted of 46 patients (21F, 25M; median age 60.3±7.2years) who had undergone 102 root canal treatments. The survival rate was 88%, with 12 teeth lost during follow-up. The success rate was 73%. In the BP group, 55 teeth were restored normally (OC group) and 41 teeth were restored at the tissue level (TL group). No difference in the success or survival rate was observed between the BP and control groups (P>0.05). Univariate Kaplan–Meier analysis revealed that only tooth type significantly affected survival status in the BP group. The analysis revealed the clinical relevance of smoking, tooth location and initial PAI on patients’ health status (P&nbsp