A Novel Educational Approach for Safe Endodontic Syringe Irrigation: A Randomized Controlled In Vitro Study.

OBJECTIVE: Syringe irrigation, commonly used for delivering sodium hypochlorite (NaOCl) during root canal treatment, requires careful handling to prevent NaOCl extrusion into periapical tissues. This randomized controlled in vitro study aimed to quantify syringe plunger forces exerted by dental undergraduates and to assess the impact of an educational intervention on adherence to safe irrigant delivery parameters. METHODS: Fifty-two undergraduates performed syringe irrigation at three intervals: baseline (T1), after two weeks (T2), and after 12 weeks (T3). At T1, irrigation was conducted without prior educational intervention, while at T2, it was preceded by an intervention. The educational intervention involved a short video highlighting safe irrigation practices, including plunger force and time recommendations for syringe irrigation. At T3, the undergraduates were randomly allocated to two groups: One received a repeated intervention, while the other did not. Syringe irrigation was performed on a 3D-printed tooth using two side-vented cannulas: one of 25 Gauge (G) and another of 30 G. A syringe equipped with a force sensor recorded the plunger forces. Based on earlier research, plunger forces exceeding 10 Newtons (N) for the 25 G cannula and 40 N for the 30 G cannula were deemed critical. The data were subjected to descriptive statistical analyses. RESULTS: Overall, the mean of maximum values of plunger forces remained under 10 N for the 25 G and below 20 N for the 30 G cannulas, with only few measurements exceeding 40 N. Instances of surpassing the critical plunger force threshold were more common with the 25 G side-vented cannula than with the 30 G variant. At T3, the group that received the repeated educational intervention exhibited lower average maximum plunger forces for both types of cannulas compared with the group that did not receive the intervention. CONCLUSION: Integrating plunger force measurements with targeted educational interventions presents an effective approach for instructing undergraduates in the proper techniques of syringe irrigation. The findings suggest that, generally, undergraduates do not apply excessive plunger forces that could risk apical irrigant extrusion. The implementation of repeated educational interventions has been shown to decrease the plunger forces exerted by undergraduates, underscoring its effectiveness in fostering safe endodontic irrigation.

Changes in periapical status of root canal-treated teeth after head and neck IMRT: a retrospective study.

The objective of this retrospective study was to analyze the effect of the intensity modulated radiotherapy (IMRT) of the head and neck region on root canal-treated teeth and their periapical changes due to radiation. Patients undergoing IMRT of the head and neck region were evaluated. Different types of teeth (molars, premolars, incisors and canines) were compared. Panoramic and dental radiographs were used to assess the periapical region of root canal-treated teeth using the periapical index (PAI) before and after radiotherapy (RT) and put in relation to the radiation dose per tooth. Further parameters (patient-, therapy- and tooth-related factors) were included in this study. One hundred and twenty-four root canal-treated teeth (maxilla and mandible) of 51 patients were observed. A radiolucency in the periapical region was seen in 34.7% of the samples before IMRT and an increasing number of 46% after IMRT (p-value 0.092). Clinical or radiological signs of osteoradionecrosis could not be determined. The only statistically significant difference was detected in regions irradiated with less than 40 Gy (p-value 0.045). In regions irradiated with higher doses (>40 Gy), comparable pathologies increased in non-significant numbers. A statistically significant increase of periapical pathologies was detected in premolars of the maxilla. The observations reported here suggest that a high radiation dose during IMRT has no significant consequences on root canal-treated teeth. To compare the success of endodontic treatment before versus after IMRT, further research needs to be done.

Guided endodontics versus conventional access cavity preparation: an ex vivo comparative study of substance loss.

BACKGROUND: To compare the outcomes of conventional access cavity preparation (CONV) versus guided endodontics (GE) for access cavity preparation in anterior teeth with pulp canal calcification (PCC) regarding root canal detection, substance loss, procedural time, and need for additional radiographs. METHODS: Extracted, sound human teeth with PCC (n = 108) were matched in pairs, divided into two groups and used to produce 18 models. An independent endodontist and a general dentist performed access cavity preparation under simulated clinical conditions on nine models each (54 teeth). The endodontist used the conventional technique and the general dentist GE. Time needed to access the root canals and the number of additional radiographs were recorded. Pre- and postoperative cone-beam computed tomography scans were obtained to measure substance loss. Statistical significance was tested by examining the overlap of 95% confidence intervals (CIs) between the groups. RESULTS: All root canals were successfully accessed by both methods. There were no significant differences in substance loss (CI: CONV 15.9-29.6 mm3 vs. GE 17.6-27.5mm3) or procedural time (CI: CONV 163.3-248.5 s vs. GE 231.9-326.8 s). However, 31 additional radiographs were required for GE compared to none for CONV. CONCLUSIONS: For access cavity preparation in teeth with PCC, both CONV by a specialist and GE by a general dentist produce good results in terms of substance loss and time requirements.

Accuracy of a dynamic navigation system for dental implantation with two different workflows and intraoral markers compared to static-guided implant surgery: An in-vitro study.

PURPOSE: To investigate the accuracy of a miniaturized dynamic navigation system with intraoral markers and two different workflows for dental implantation and to compare with static computer-assisted implant surgery (sCAIS) surgery. MATERIALS AND METHODS: Two operators performed a total of 270 implant insertions in polyurethane mandibular models under simulated clinical conditions. Implants were placed after CBCT-based virtual planning in three different groups: two workflows utilizing dynamic computer-assisted implant surgery (dCAIS; DG1: marker in CBCT; DG2: 3D-printed marker) and the others with sCAIS (TG: template guided). Postoperative surface scans were matched to the planning data and allowed an evaluation of the angular and spatial deviation between the planned and the actually achieved implant position. Descriptive statistics were followed by a Mixed Model Analysis to determine the influence of the operator, the method, and operating area on different accuracy parameters and the random effect of the model number. RESULTS: The mean angular deviation ranged from 2.26° (DG1) to 2.96° (TG). The mean 3D deviation at the implant's tip ranged from 1.08 mm (TG) to 1.51 mm (DG2) and at the implant's base from 0.69 mm (TG) to 1.49 mm (DG2). The operator showed no significant influence on the accuracy. The method showed significant influence on singular parameters and the operating area on all spatial accuracy parameters. CONCLUSIONS: Dynamic navigation systems with intraoral markers enable accurate implant positioning, which is comparable to the static-guided implant surgery. 3D-printed markers provide less accurate results compared to prefabricated markers, attached before CBCT scan.

Evaluation of five methods to identify composite restorations in human teeth on a forensic purpose-an ex vivo comparative study.

The use of tooth-colored composite resin materials in dentistry is increasing. As composite restorations appear similar to the natural tooth structure, their detection is becoming more challenging. The aim of this study was to compare five diagnostic methods for detection of dental restorations and to create reliable postmortem dental records for forensic purposes. A conventional examination method without a direct light source (CONV), with a dental loupe light (DL), Galilean loupes with a direct light source (GDL), a fluorescence-inducing device (FIT), and intraoral radiographs (RX) were compared. Dentists specializing in conservative dentistry or oral surgery and dentistry students participated. Regarding sensitivity, specificity, positive predictive value, and negative predictive value, FIT and RX showed significantly higher results than CONV, DL, and GDL. RX and FIT showed comparable results in identifying composite restorations but depending on their location. The combination of both methods may lead to even better results. In conclusion fluorescence-inducing devices show good results in identifying composite restorations and therefore should be considered as a standard tool in forensic examinations. Another advantage is their small size, low cost, and mobility. Good illumination and magnification devices are recommended to enhance performance during conventional examinations. Involving dentists specialized in conservative dentistry could contribute to dental identification.

Detection and Removal of Tooth-Colored Composite Resin using the Fluorescence-Aided Identification Technique.

The detection and removal of tooth-colored filling materials is a major challenge for every dentist. The Fluorescence-aided Identification Technique (FIT) is a noninvasive tool to facilitate the distinction of composite resin material from sound tooth substance. Compared to conventional illumination, FIT is a very accurate, reliable, and fast diagnostic method. When composite resin is illuminated with a wavelength of approximately 398 ± 5 nm, certain fluorescent components make the composite resin appear brighter than the tooth structure. Any fluorescence-inducing light source with the appropriate wavelength can be used for this method. Optimally, this technique is used without additional natural or artificial lighting. The application of FIT can be used for diagnostic purposes, for example, dental charts, and additionally for the complete and minimally invasive removal of composite resin restorations, bracket debonding, and trauma splint removal. The assessment of volumetric changes after composite removal can be provided by overlapping pre- and postoperative scans and subsequent calculation using suitable software.

Guided Endodontics: Three-dimensional Planning and Template-aided Preparation of Endodontic Access Cavities.

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, pulpitis or apical periodontitis may develop in the long term. Root canal treatment of teeth with severe PCO and pulpal or periapical pathosis is challenging for general practitioners and even for well-equipped endodontic specialists. To ensure detection of the calcified root canal and avoid excessive loss of tooth structure or root perforation, static navigation using templates ("Guided Endodontics") was introduced a few years ago. The general workflow includes three-dimensional imaging using cone-beam computed tomography (CBCT), a digital surface scan, and superimposition of both in a planning software. This is followed by virtual planning of the access cavity and the design of a template that will guide the drill to the desired target point. To do this, a true-to-scale virtual image of the drill must be placed in a way that the tip of the drill reaches the orifice of the calcified root canal. Once the template has been fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) or a 3D printer, guided preparation of the access cavity can be performed clinically. For research purposes, a postoperative CBCT image can be used to quantify the accuracy of the access cavity performed. This work aims to present the technique of static guided endodontics from imaging to clinical implementation.

Dynamic Navigation in Endodontics: Guided Access Cavity Preparation by Means of a Miniaturized Navigation System.

In the case of teeth with pulp canal calcification (PCC) and apical pathology or pulpitis, root canal treatment can be very challenging. PCC are common sequelae of dental trauma but can also occur with stimuli such as caries, bruxism, or after placing a restoration. In order to access the root canal as minimally invasive as possible in case of a necessary root canal treatment, dynamic navigation has recently been introduced in endodontics in addition to static navigation. The use of a dynamic navigation system (DNS) requires pre-operative cone-beam computed tomography (CBCT) imaging and a digital surface scan. If necessary, reference markers must be placed on the teeth before the CBCT scan; with some systems, these can also be planned and created digitally afterward. By means of a stereo camera connected to the planning software, the drill can now be coordinated with the help of reference markers and virtual planning. As a result, the position of the drill can be displayed on the monitor in real-time during preparation in different planes. In addition, the spatial displacement, the angular deviation, and the depth position are also displayed separately. The few commercially available DNS mostly consist of relatively large camera-marker-systems. Here, the DNS contains miniaturized components: a low-weight camera (97 g) mounted on the micromotor of the electric handpiece utilizing a manufacturer-specific connecting mechanism and a small marker (10 mm x 15 mm), which can be easily attached to an individually manufactured intraoral tray. For research purposes, a post-operative CBCT scan can be matched with the pre-operative one, and the volume of tooth structure removed can be calculated by the software. This work aims to present the technique of guided access cavity preparation by means of a miniaturized navigation system from imaging to clinical implementation.

A critical analysis of research methods and experimental models to study working length determination and the performance of apex locators - A narrative review with recommendations for the future.

Outcome studies have repeatedly shown that the apical endpoint of root canal preparation and filling is a determinate factor for the outcome of root canal treatment. Accurate determination of root canal length enhances the efficacy of chemo-mechanical disinfection and prevents over-/under-instrumentation and over-/under-filling in relation to the canal terminus. Long and short root canal fillings are consistently reported to be associated with higher rates of post-treatment endodontic disease. Although standards for undertaking and reporting diagnostic accuracy studies are available, publications dealing with the determination of root canal length are highly heterogeneous and describe procedures inconsistently. The aim of this review is to critically assess the methodology of publications in the past three decades. The process of planning, performing and analysing working length studies are presented stepwise with suggestions to optimize research methods.

Present status and future directions - Guided endodontics.

Luxation injuries and other stimuli may lead to a pulp canal obliteration (PCO). Even though the apposition of tertiary dentine is a sign of a vital pulp, in some cases root canal treatment is indicated in the long term due to apical periodontitis or pulpitis. Depending on the extent of PCO, root canal treatment may be challenging even for experienced and well-equipped endodontic specialists. The 'guided endodontics' (GE) technique was introduced 6 years ago as an alternative to conventional access cavity preparation for teeth with PCO and apical pathosis or irreversible pulpitis. Using three-dimensional radiological imaging such as cone-beam computed tomography and a digital surface scan, an optimal access to the orifice of the calcified root canal can be planned virtually with appropriate software. GE is implemented either with the help of templates analogous to guided implantology (= static navigation) or by means of dynamic navigation based on a camera-marker system. GE has emerged as a field of research in the last 6 years with very promising laboratory-based results regarding the accuracy of guided endodontic access cavities for both static and dynamic navigation. Clinical implementation seems to provide favourable results, but the evidence is mainly based on numerous case reports and a few case series. This narrative review aims to provide an update on the present status of GE and to identify relevant research areas that could contribute to further improvements of this technique.

Real-Time Guided Endodontics with a Miniaturized Dynamic Navigation System Versus Conventional Freehand Endodontic Access Cavity Preparation: Substance Loss and Procedure Time.

INTRODUCTION: This study aimed to evaluate substance loss and the time required for access cavity preparation (ACP) using the conventional freehand method (CONV) versus a miniaturized dynamic navigation system of real-time guided endodontics (RTGE) in an in vitro model using 3-dimensional-printed teeth. METHODS: Nine human anterior maxillary teeth were selected and micro-computed tomographic scanned. Root canals were virtually reduced to 2 mm below the cementoenamel junction. The teeth were digitally duplicated and mirrored to yield 6 different models with 6 single-rooted teeth each. The models were 3-dimensionally printed using radiopaque resin and consecutively mounted on a dental mannequin for ACP. Two operators with 12 and 2 years of clinical experience, respectively, received 6 models (36 teeth) each and performed ACP on half of the models using RTGE (after digital planning) and CONV on the other half 2 weeks later. The time was recorded. Postoperative substance loss was measured by cone-beam computed tomographic imaging. The differences in time and substance loss between the methods and operators were evaluated by the t test. RESULTS: Overall, substance loss was significantly lower with RTGE than CONV (mean = 10.5 mm3 vs 29.7 mm3), but both procedures took a similar time per tooth (mean = 195 vs 193 seconds). Operator 1 (more experienced) achieved significantly less substance loss than operator 2 with CONV (mean = 19.9 vs 39.4 mm3) but not with RTGE (mean = 10.3 vs 10.6 mm3). CONCLUSIONS: RTGE is a practicable, substance-sparing method performed in comparable time as CONV. Moreover, RTGE seems to be independent of operator experience.

Apical Pressure Generated Using Conventional Syringe Irrigation in Immature Teeth-An In Vitro Study.

This in vitro study aimed to evaluate apical pressure during irrigant delivery with syringe irrigation in immature teeth with an open apical foramen. Conventional syringe irrigation was performed in a 3D-printed immature incisor. A 5 mL syringe combined with 25 G and 30 G cannulas was used. Open-ended and side-vented needle tip designs were assessed. Cannulas were placed at tooth length (TL), TL -1 mm, TL -2 mm, and TL -4 mm. The syringe plunger was moved with a force of 10 N, 20 N, 40 N, and 80 N to simulate clinical conditions. A pressure sensor measured periapical pressures during irrigation. Each experiment was repeated 10 times. Data were analyzed descriptively (maximum, mean, standard deviation, 95% CI) with the critical threshold indicative of extrusion set at 7.64 mbar. 30 G cannulas with both needle tip designs never exceeded the threshold at any TL with a plunger force of 10-40 N. At 80 N, 30 G open-ended cannulas exceeded the threshold in 10%, 30 G side-vented in 20-60% of the measurements. At any TL, 25 G open-ended cannulas and 25 G side-vented cannulas never crossed the threshold with forces of 10-20 N and 10 N, respectively. Consequently, 30 G cannulas with both designs can be recommended for irrigant delivery in immature teeth. 25 G cannulas ought to be used with caution.

Apical pressures generated by several canal irrigation methods: A laboratory study in a maxillary central incisor with an open apex.

AIM: A laboratory study to determine the apical pressure generated by seven canal irrigation methods in an anterior tooth with an open apex. METHODOLOGY: Canal irrigation was performed on a 3D-printed central maxillary incisor with an open apex (maximum diameter of 2.1 mm). Ultrasonically activated irrigation (UAI), sonic activation (EDDY), negative pressure irrigation (EndoVac), the self-adjusting file (SAF) and the XP-endo Finisher were employed at tooth length (TL), TL-1 mm, TL-2 mm and TL-3 mm. UAI was tested at three intensity levels additionally. Hydrodynamic irrigation with RinsEndo was performed in the pulp chamber, at the canal orifice, the coronal third, the middle of the canal and at TL. Er:YAG laser activation, at four frequency settings, was performed in the pulp chamber and at the orifice of the canal. The pressure of the fluid towards the canal terminus generated by activation was directly transferred to a pressure sensor with a range of 0 to 120 mmHg and a response time of ≤0.5 ms. The critical threshold for apical extrusion of the irrigant was set at 5.73 mmHg (lower limit of the central venous pressure: 5.88 ± 0.15 mmHg). Each experiment was repeated ten times. The tests were followed by descriptive analyses (maximum, mean, standard deviation, 95% confidence interval). RESULTS: EndoVac, the SAF, the XP-endo Finisher, and UAI never exceeded the critical threshold at any insertion depth or intensity level. Er:YAG laser activation exceeded the critical threshold exclusively at frequency settings that varied from the manufacturer's recommendation. EDDY at TL and RinsEndo at any insertion depth exceeded the critical threshold in 100% of the measurements. EDDY at TL-1,-2, and-3 mm crossed the critical threshold in 30%, 10%, and 20% of the measurements, respectively. CONCLUSIONS: In a simulated maxillary central incisor with an open apex, irrigation with EndoVac, Er:YAG laser activation, UAI, the SAF, and the XP-endo Finisher generated apical pressures below the critical threshold of 5.73 mmHg. By contrast, using EDDY and RinsEndo for irrigation produced higher apical pressures that exceeded the critical threshold.

Suitability of Magnetic Resonance Imaging for Guided Endodontics: Proof of Principle.

INTRODUCTION: This proof-of-principle study aimed to demonstrate that magnetic resonance imaging (MRI) is sufficiently accurate for the detection of root canals using guided endodontics. METHODS: One hundred extracted human teeth (anterior and premolar) were mounted onto 5 mandibular and 5 maxillary models, fitted with splints designed to accommodate a thin layer of aqueous gel for indirect imaging, and scanned by MRI. After MRI and intraoral scans were aligned using planning software, access cavities were planned virtually, and templates were manufactured with computer-aided design/computer-aided manufacturing, the access cavities were prepared. Cone-beam computed tomographic scans were performed and matched with the virtual preoperative planning data to determine the accuracy of access cavity preparation in terms of deviation between planned and prepared cavities in the mesiodistal and buccolingual dimensions and angle. Descriptive statistical analysis was performed, and the mean values were compared using the t test. RESULTS: Ninety-one of 100 root canals were successfully scouted after MRI-guided access cavity preparation. The mean angle deviation was 1.82°. The mean deviation ranged from 0.21-0.31 mm at the base of the bur and from 0.28-0.44 mm at the tip of the bur. Preparation in the buccolingual dimension was significantly more precise in mandibular compared with maxillary teeth, and accuracy in the mesiodistal dimension was more precise in anterior teeth compared with premolars. CONCLUSIONS: This in vitro study demonstrated the suitability of MRI for guided endodontic access cavity preparation.

How well can today's tooth-colored dental restorative materials reproduce the autofluorescence of human teeth? - Ambition and reality!

OBJECTIVES: The autofluorescence of dental hard tissues has been known for over 100 years. Thus, manufacturers add fluorophores to dental restorative materials to improve the esthetic properties of these materials. So far, there has been no study evaluating the ability of these fluorophores to reproduce the autofluorescence of dental hard tissues. MATERIALS AND METHODS: A total of 240 different color shades representing 17 different brands of fluorescent light-curing RBC and CAD/CAM restorative materials were analyzed with a monochromator-based microplate reader. Additionally, combined enamel-dentin specimens (n = 11) were analyzed as "gold standard". The total fluorescence (TF) and the physiologically relevant luminous efficiency function adjusted total fluorescence (TFa ) were determined. The differences between the brands and the enamel-dentin specimens were further evaluated and visualized as contour plots. RESULTS: Merely the TFa of the brands CERASMART™, Filtek Supreme XTE™, KZR-CAD HD 2, and LuxaCam composite were not significantly different to the enamel-dentin specimens. The analysis of the contour plots revealed that even these four materials showed a fluorescence excess for the excitation wavelengths below about 400 nm and a deficit above this wavelength. CONCLUSION: None of the materials analyzed in this study were able to reproduce the natural fluorescence spectrum of the enamel-dentin specimens. CLINICAL SIGNIFICANCE: Unlike the statements and images of blue fluorescent materials in the manufacturers' brochures, none of the materials examined here is fully capable of reproducing the natural autofluorescence of teeth.

Accuracy of the fluorescence-aided identification technique (FIT) for detecting tooth-colored restorations utilizing different fluorescence-inducing devices: an ex vivo comparative study.

OBJECTIVES: The aim of the present study was to compare the accuracy of the conventional illumination method (CONV) and the fluorescence-aided identification technique (FIT) for distinguishing between composite restorations and intact teeth using different fluorescence-inducing devices commonly used for FIT. MATERIALS AND METHODS: Six groups of six dentists equipped with one of six different FIT systems each independently attempted to identify composite restorations and intact teeth on a full-mouth model with 22 composite restorations using CONV and, 1 h later, FIT. The entire procedure was repeated 1 week later. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values, including 95% confidence intervals (CI), were calculated for CONV and FIT overall and for each device. The influence of examiner age, method, and device on each parameter was assessed by multivariate analysis of variance. RESULTS: The sensitivity (84%, CI 81-86%), specificity (94%, CI 93-96%), PPV (92%, CI 90-94%), and NPV (90%, CI 88-91%) of FIT was significantly higher than that of CONV (47%, CI 44-50%; 82%, CI 79-84%; 66%, CI 62-69%, and 69%, CI 68-71%, respectively; p<0.001). The differences between CONV and FIT were significant for all parameters and FIT systems except VistaCam, which achieved no significant difference in specificity. Examiners younger than 40 years attained significantly higher sensitivity and negative predictive values than older examiners. CONCLUSIONS: FIT is more reliable for detecting composite restorations than the conventional illumination method. CLINICAL RELEVANCE: FIT can be considered an additional or alternative tool for improving the detection of composite restorations.

Dental trauma splint color preference of adults.

The prevalence of dental trauma among children and adults is high. Most luxated teeth need splinting. The Titanium Trauma Splint (TTS) is a widely used appliance with good performance properties. Esthetics is increasingly important for most patients. Splints placed on the front teeth have a clearly visible impact on patients' appearance and, thus, on their quality of life during splint therapy. Therefore, the aim of the present study was to evaluate the esthetic preferences of adult patients with regard to different splint color and surface finish characteristics. TTS appliances were fabricated in four different colors (silver, gold, green and violet) and two different surface finishes (matt or polished) to yield a total of eight variants. The finished splints were applied to the teeth of a human model, photographed by a professional photographer, and printed as posters. Adults aged between 18 and 79 years were asked to complete a written survey containing items regarding their TTS color and surface preferences based on the posters with photographs as well as questions about previous tooth bleaching treatments, the importance of having esthetic teeth in general, and the prioritization of esthetic versus function-driven dentistry. Over 80% of participants preferred the silver matt splint over the other variants. Neither gender nor age nor other parameters had a significant influence on the choice of splint color or surface. Women placed greater importance on esthetic rather than function-driven treatment.

Reentry of endodontic access cavities: composite residue and loss of tooth substance.

The purpose of this study was to investigate the ability of dentists to remove composite fillings from endodontic access cavities using illumination from a conventional light source (CLS) versus the fluorescence-aided identification technique (FIT) in terms of completeness, selectivity and treatment duration. Therefore, two independent operators removed composite resin from six sets of root-filled incisors in a maxillary model under simulated clinical conditions using the CLS or FIT method (twelve teeth per operator and technique). The duration of treatment was recorded and before-after micro-CT scans were superimposed for volumetric assessment of treatment completeness and selectivity. Statistical significance was determined by t-testing and two-way ANOVA for operator comparison. Overall, there was no significant difference between FIT and CLS in terms of volume, height and area of composite residues (p=0.98 / p=0.75 / p=0.64) and regarding hard tissue loss in terms of volume, depth and area (p= 0.93 / p= 0.70 / p= 0.14). However, there was a significant difference between the two groups regarding treatment time (FIT= 428s, CLS=523s; p=0.023). Significant differences between operators regardless of method were found for volume, height and area of composite residues (p<0.05) and also for defect area (p=0.01) and time (p<0.001). Significant differences between operators including the method was only found for height of composites (p=0.037). It can be concluded, that composite remnants and tooth structure losses may occur after reentry of root-filled teeth regardless of the illumination method (conventional vs. fluorescence-aided) and operator, but preparation was less time-consuming with FIT.

Serious injuries and dental trauma in the line of police duty and their long-term consequences.

Confrontations between police officers and citizens have become almost commonplace in today's world. The propensity for violence towards police officers is an ongoing topic. Statistics show a clear increase in violent crimes of this nature. The aim of the present study was to evaluate police officers' risk of injury including orofacial involvement in the line of duty. One hundred and sixty-eight members of a regional police corps in northwestern Switzerland were interviewed with the help of an online questionnaire. The data were kept completely anonymous. Survey questions related to police officers' life on and off the job and focused on serious line-of-duty injuries (LODIs) that led to a loss of work time. LODIs resulting in work absences were not uncommon: 60.9% had been injured in the line of duty. During their free time, the officers showed a moderate risk-taking behavior (mean 50, IQR 30-67.2) and a slightly higher level of perceived risk of being injured while on duty (mean 59.1, SD 20). Most line-of-duty injuries occurred during the first 15 years of service. Among the injured police officers, the level of perceived threat of violence while on duty (mean 40, IQR 20-60) was higher than their non-injured colleagues (mean 50, IQR 21.2-60). The most commonly injured body parts were the hands (20.8%), head (14.9%) and knees (11.3%). Dental injuries were reported in only one case (0.6%). Greater work experience seems to improve the reactions and protective behavior of this occupational group in dangerous situations. Albeit the risk of being injured is high among police officers, dental trauma and orofacial involvement occurs rarely.

Dental trauma and tongue injuries in professional alpine ski racing-A worldwide survey.

BACKGROUND/AIM: Skiing is a sport with a medium risk of injuries, and injuries are increasingly common among professional alpine skiers. Examples of other medium-risk sports are for example handball, basketball, and karate. The aim of this study was to assess the frequency of dental trauma in professional alpine skiing and to determine whether the frequency of dental injuries is associated with a skier's performance level, alpine skiing discipline, and/or years of skiing experience. MATERIAL AND METHODS: A questionnaire consisting of 17 questions was distributed to professional male ski racers to gather information about their skiing discipline (category), performance level, and injuries, particularly dental trauma. RESULTS: A total of 161 out of 190 skiers returned the survey, with a response rate of 84.2%. Of these, 134 (83.2%) had suffered alpine ski racing-related injuries during their career and 38 (23.6%) reported skiing-related dental trauma-most commonly crown fractures (65.8%, n = 25), which mainly involved the maxillary or mandibular incisors (76.0%, n = 28). Ski racers with higher performance levels were more likely to experience dental injuries, but the difference in the frequency of dental trauma between participants in the speed versus technical category was not significant. Likewise, the number of years of ski racing experience did not impact the frequency of dental injuries. The participants rarely wore custom-made mouthguards (6.8%, n = 11). None of those who reported dental injuries were wearing a custom-made mouthguard when the injury occured. They preferred to wear chin guards, over-the-counter mouthguards, or no mouthguards. CONCLUSION: Professional alpine ski racing has a medium risk of dental trauma, which further increases with skier performance level. The participating skiers rarely wore custom-made mouthguards.