Instrument fracture in periodontal therapy: ethical disclosure and clinical management - a case report.

Periodontal instrument fractures are rare events in dentistry, with limited literature available on their occurrence and management. This case report highlights an incident involving the fracture of a periodontal sickle scaler blade during manual instrumentation for the removal of calculus. The fracture occurred during instrumentation on the mesial surface of the maxillary right second molar, and the separated blade was subsequently pushed into the sulcus. A radiographic assessment was performed to verify the precise location of the fractured segment. Following confirmation, the broken blade was subsequently retrieved using curved artery forceps. The case report highlights factors contributing to instrument fractures, emphasizing the importance of instrument maintenance, sterilization cycles, and operator technique. Ethical considerations regarding patient disclosure, informed consent, and instrument retrieval methods are well discussed. This case underscores the importance of truthful communication, the proper use of instruments, equipment maintenance in dentistry, and the significance of ongoing professional development to enhance treatment safety, proficiency, and ethical standards in dental care.

Comparative evaluation of hand and rotary file systems on dentinal microcrack formation during pulpectomy procedure in primary teeth: an in vitro study.

PURPOSE: Pulpectomy can be used for the management of deep dentinal carious lesions in primary teeth which can be restored. Mechanical preparation of root canals can be performed using hand or NiTi rotary files. However, this may cause dentinal stress and consequently dentinal microcracks. Hence, the aim was comparative evaluation of hand and rotary file systems on dentinal microcrack formation during pulpectomy procedure in primary teeth. METHODS: 60 extracted primary molar teeth were selected comprising of 80 root canals. Simple random sampling was used to divide root canals into four groups (n = 20): Group A-Hedstrom file, Group B-Pro AF Baby Gold rotary, Group C-ProTaper Next rotary, and Group D-unprepared group. Assessment was conducted on presence or absence of microcracks using Chi square test (p < 0.05). RESULTS: The total number of microcracks in Group A: one (5%), Group B: four (20%), Group C: nine (45%) and Group D: zero (0%) which was statistically significant (p = 0.002). At cervical third, the number of microcracks seen with Group A: one (5%), Group B: zero (0%), Group C: five (25%) and Group D: zero (0%) (p = 0.005). At the middle third, the number of microcracks seen in Group A: zero (0%), Group B: four (20%), Group C: four (20%) and Group D: zero (0%) (p = 0.029). CONCLUSION: The study concluded that dentinal microcracks are formed with both hand and rotary file systems in primary teeth. ProTaper Next showed significantly higher number of microcracks, followed by ProAF Baby Gold and H files.

Cone-beam computed tomography analysis of primary root canals transportation and dentin loss after instrumentation with two-pediatric rotary files.

BACKGROUND: This in vitro study aims to compare rotary files (Fanta and Zuanba) with manual K files according to the amount of dentin removed and canal transportation in primary mandibular second molars by CBCT images. METHODS: This experimental study was conducted on 60 extracted human second primary molars. That were divided into three groups according to root canal preparation group "I" instrumented with manual K-files, group "II" instrumented with rotary Fanta files, and group "III" instrumented with rotary Zuanba files. After root canal preparation, teeth were scanned before and after mechanical preparation with CBCT scanner. Then the amount of dentin removed was determined at three levels, including the coronal, middle and apical levels. Data were statically analysed using the Kruskal-Wallis test. RESULT: No statistically significant difference in the amount of dentin removed were noted between the manual and the rotary groups at the coronal and apical RC levels (P = 0.420) and (P = 0.819) respectively but significant difference was noted at the middle third (P = 0.043). Regarding RC transportation, no significant difference was noted among the three groups with the exception of the apical RC level (P = 0.043). CONCLUSION: Although no significant differences were noted between rotary and manual files, the rotary files showed better performance.

Present status and future directions: Removal of fractured instruments.

The success rate of fractured instrument retrieval varies because it is dependent mainly on several factors including the visibility of the fractured instrument, the length of the fractured instrument in relation to the curvature of the canal and the techniques applied to each case. This review aims to update the present status on removal of fractured instruments to identify factors and variables that could affect the success of fractured instrument retrieval based on both the preparation techniques and the instrument retrieval techniques. On the other hand, future directions of fractured instrument retrieval should focus on management of nonvisible fractured instruments since the removal of those instruments is deemed unpredictable with the current techniques, whereas the removal of visible fractured instruments is considered predictable now. Another possible direction of it is that there might be no more instrument fracture due to possible significant changes in the root canal preparation technique which may dispense with the use of rotary instruments.

Efficacy, tolerability, and safety of an innovative medical device for improving oral accessibility during oral examination in special-needs patients: A multicentric clinical trial.

BACKGROUND: People with special needs have high unmet oral healthcare needs, partly because dentists find it difficult to access their oral cavity. The Oral Accessibility Spatula aims to improve oral accessibility. This prospective multicenter interventional open-label non-randomized patient-self-controlled trial assessed the ability of the spatula to improve the oral accessibility of special-needs patients during dental examinations. METHODS: The cohort was a convenience sample of minor and adult patients with special needs due to physical, intellectual, and/or behavioral disorders who underwent dental check-up/treatment in five French tertiary hospitals/private clinics in 2016-2018 and evinced some (Venham-Score = 2-4) but not complete (Venham-Score = 5) resistance to oral examination. After inclusion, patients underwent oral examination without the spatula and then immediately thereafter oral examination with the spatula. Primary outcome was Oral Accessibility Score (0-12 points; higher scores indicate visualization and probing of the tooth sectors). Secondary outcomes were patient toleration (change in Venham-Score relative to first examination), safety, and Examiner Satisfaction Score (0-10; low scores indicate unsatisfactory examination). RESULTS: The 201 patients were mostly non-elderly adults (18-64 years, 65%) but also included children (21%), adolescents (11%), and aged patients (3%). One-quarter, half, and one-quarter had Venham-Score = 2, 3, and 4 at inclusion, respectively. The spatula significantly improved Oral Accessibility Score (4.8 to 10.8), Venham-Score (3.1 to 2.6), and Examiner Satisfaction Score (3.4 to 7.2) (all p<0.001). There were no severe spatula-related adverse events. CONCLUSION: The spatula significantly improved oral access, was safe and well-tolerated by the patients, and markedly improved oral examination quality.

Cervicofacial and mediastinal emphysema following minor dental procedure: a case report and review of the literature.

BACKGROUND: Subcutaneous cervical emphysema is a clinical sign associated with many conditions, including laryngotracheal trauma, pneumothorax and necrotizing deep tissue infections. CASE PRESENTATION: We discuss a case of a 76-year-old man presenting with extensive cervical emphysema a few hours after a minor dental filling procedure. The CT-scan revealed a significant amount of air within the cervical and mediastinal spaces, reaching lobar bronchi. Vitals were within normal values Bloodwork demonstrated an elevation of creatinine kinase (3718; normal < 150) and mild leukocytosis (WBC = 11.6). We decided to proceed to an urgent cervical exploration to exclude necrotizing fasciitis. This revealed air but no tissue necrosis nor abnormal fluid. The patient improved clinically and was discharged two days later with oral antibiotics. Although cervicofacial subcutaneous emphysema following dental procedures has been reported, it is usually less extensive and involving more invasive procedures using air-driven handpieces. CONCLUSION: As an otolaryngologist confronted with extensive subcutaneous emphysema following a potential entry route for an aggressive infection, given the seriousness of this diagnosis, the decision of whether or not to perform a diagnostic surgical exploration should remain.

Assessment of occupational noise-related hearing impairment among dental health personnel.

OBJECTIVES: The purpose of the study was to examine hearing thresholds among dental personnel. The secondary aim was to evaluate sound levels among dental equipment that dental personnel are exposed to. METHODS: Two hundred forty-four dentists, dental technicians, dental assistants, and dental students participated. Sixty-two participated as a control group. Audiological thresholds for the test groups were compared to the control group. All participants were from Jordan University Hospital. Participants completed a questionnaire in addition to their audiometric testing. Otoscopy, tympanometry, and pure tone audiometry were included in their assessment. Three-factor ANOVA and t tests were utilized to assess the statistical differences of hearing thresholds among the groups and between the two ears. Pearson correlation test was used to assess the effect of age, experience, and duration of exposure on the degree of hearing loss in the test groups for both ears. RESULTS: The authors reported statistically significant differences among hearing thresholds between the control group and others. Left hearing thresholds were noted to be significantly poorer in the left versus right ear at 1000, 2000, 4000, and 8000 Hz in dental assistants. The authors also reported a significant relationship between the degree of hearing impairment among dental assistants and the daily duration of exposure to dental occupational noise, followed by age. CONCLUSION: Hearing impairment was higher among dental professionals than the control group and especially among dental assistants and technicians. The authors recommended screening guidelines and adapting hearing protection methods for dental professionals and particularly for dental assistants and technicians.

Factors influencing incidents of complications while using nickel-titanium rotary instruments for root canal treatment.

BACKGROUND: To investigate the complications associated with the use of nickel titanium rotary instruments (NiTi-RIs) for root canal treatments (RCTs), in Saudi Arabia dental practice, and to explore the influencing factors. METHODS: After obtaining an ethical approval, two pilot studies were conducted to formulate the final questionnaire. The sample size was measured taking into consideration 60% expected response rates and confidence level of 99.9%. The questionnaire was emailed to 600 general dentists (GDs) randomly selected from the dental register and all of the endodontists (175). The email's introduction clarified objectives of the study and guaranteed that all of the collected information would remain confidential. A reminder was sent after 10 weeks. The data were collected and analyzed using the chi-squared test at a 0.05 significance level. RESULTS: With a 51% overall response rate, 71.9% off the respondents used NiTi-RIs. The majority (83.1%) experienced complications while using NiTi-RIs; with the instruments' fracture being significantly the most common complication (52.7%) (p < 0.001). The majority (87.7%) experienced NiTi-RIs' fracture at least once; with more endodontists (94.3%) than GDs (83.3%) (p < 0.001). The greater the number of weekly performed RCTs and participants' experiences, the more NiTi-RIs fractures and the greater the number of fracture incidents (p < 0.001). While 60% of those who performed 1-3 RCTs per week experienced NiTi-RIs fractures, 100% of those who performed more than 12 RCTs per week did so. The highest percentage of those who experienced more than 10 fractured NiTi-RIs (60%) was within the group who performed more than 12 RCTs per week. Although fracture incidents decreased with a smaller number of reuses, there was no significant correlation between the number of fractured instruments and NiTi-RIs discard strategy (p ≥ 0.05). CONCLUSION: Fracture incidence was the most common complication while using NiTi-RIs, regardless of the clinicians' experiences and skills. While the single use may reduce NiTi-RIs fractures, to some extent, the greater number of RCTs performed per week was the most influential factor.

Effect of Root Canal Preparation Techniques on Crack Formation in Root Dentin.

INTRODUCTION: The aim of this study was to assess the frequency of root crack formation caused by the use of manual instrumentation, 2 rotary systems, and 1 reciprocating system using light-emitting diode transillumination. METHODS: One hundred fifty mandibular premolars were randomly divided into 5 groups (n = 30): control 1, no intervention; control 2, instrumented with hand files; group 3, instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Ballaigues, Switzerland); group 4, instrumented with OneShape rotary files (Micro-Mega, Besancon, France); and group 5: instrumented with the WaveOne reciprocal system (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The slices were inspected under a stereomicroscope with light-emitting diode transillumination from the buccal, lingual, mesial, and distal directions at ×40 magnification to determine the presence/absence of cracks (dentinal defects). The chi-square test was used to analyze the data. RESULTS: There was a significant difference among the groups in crack frequency (P < .05). The 2 single systems had significantly higher cracks than the other 3 groups. At 3 mm from the apex, there were significantly more cracks in groups 4 and 5 than in groups 1, 2, and 3 (P < .05). At 6 mm from the apex, no significant difference was noted (P > .05). At 9 mm from the apex, the frequency of cracks in group 3 was significantly higher (P < .05). CONCLUSIONS: According to the results, using rotary instrumentation can result in some dentinal defects, and single-file systems, regardless of motion type, can cause significantly higher crack formation in the apical third of root canals.

Influence and safety of electronic apex locators in patients with cardiovascular implantable electronic devices: a systematic review.

The widespread use of cardiovascular implantable electronic devices has increased concerns regarding using electronic apex locators in patients with these devices. This systematic review investigated the effects and safety of using electronic apex locators in patients with cardiovascular implantable electronic devices. METHODS: An electronic search in the Cochrane Library, PubMed (MEDLINE), ScienceDirect, and Scientific Electronic Library Online (Scielo) databases for relevant articles published between December 2000 and December 2018 was performed. The search strategy centered on terms related to electronic apex locators use during root canal treatment in patients with cardiovascular implantable electronic devices. RESULTS: Seven studies (five in vitro and two in vivo) fulfilled the inclusion criteria for this review. It was found that electronic apex locators can be used safely in patients with cardiovascular implantable electronic devices, when general precautions are followed. CONCLUSIONS: Although the present review suggests that electronic apex locators can be used safely in patients with implantable cardioverter defibrillators, consultation with patients' cardiologists remains advisable.

Straight to the point: considering sharp safety in dentistry.

All members of the clinical dental team face a daily risk of a personal sharp injury. A wide range of sharp instruments are used, some of which are specifically designed to easily pierce the skin and mucosa. The instruments are placed, moved, passed between colleagues, used for treatment, replaced and cleaned, all in relatively confined areas. The clinical dental workplace and the decontamination unit are both therefore sharp-risk environments. There is a clear risk of a sharp injury and the potential consequences of occupational exposure to blood-borne pathogens are at least inconvenient and at worst, career and even life threatening. However, good sharp safety is not universally understood and practised throughout the dental profession. This paper considers the risk of sharp injury in dentistry and discusses some of the methods used to improve sharp safety.

Reliability, validity, and sex differences in a quantitative gag reflex measurement method.

A reliable assessment method is required to manage the gag reflex. We tested the inter- and intra-examiner reliability and validity of a quantitative measurement method and evaluated the differences between sexes. This study included 21 healthy adults (10 women, 11 men; mean age, 27.1 ± 9.9 years). An examiner inserted a standard saliva ejector slowly down the participant's throat to determine the maximum tolerance of the gag reflex; the insertion depth was used as an index of gag reflex. The reflex was measured by one examiner during two sessions (S1 and S3) and by a second examiner during one session (S2) under the same conditions. The galvanic skin response (GSR) and heart rate (HR) were recorded during each session to test the method validity. Data were analysed using the intraclass correlation coefficient (ICC), paired t test, and two-way repeated-measures analysis of variance. The ICC of the gag reflex measurements was 0.91 between S1 and S2, and 0.93 between S1 and S3. The GSR and HR increased significantly after the maximum tolerance of the reflex in S1, S2, and S3 (GSR: P < 0.001, P = 0.004, P = 0.001, respectively; HR: all, P < 0.001). Differences in the measurements according to sex and session were not significant. Our method exhibited excellent inter- and intra-examiner reliability and was unaffected by the participants' sex. Measurement revealed significant autonomic reactivity, which is common for this reflex. Consequently, this method may be used in clinical and laboratory-based applications.

Heat Production and Drill Wear Following Osseous Resective Surgery: A Preliminary In Vitro SEM Study Comparing Piezosurgery and Conventional Drilling.

The aim of this pilot in vitro study was to evaluate material wear and temperature variations after using conventional rotating bur and piezosurgical insert for osseous resective surgery in bovine bone blocks under physiologic irrigation. Wear evaluation was carried out by measuring cutting time, and wear mechanisms were analyzed by scanning electron microscopy. Time analysis showed greater material wear and higher heat production with the piezoelectric insert. However, temperatures remained below values of clinical concern even after a cutting time of 20 minutes. Conversely, bone surface appeared irregular in shape with bone debris and signs of thermal damage on the bur-drilled surface, probably due to the more traumatic action of the diamond-coated bur.

Foreign bodies in the interior of the maxillary sinus: diagnosis by cone beam computed tomography.

To avoid complications, the intimate relation between the maxillary sinus and dental roots deserves attention during surgical procedures. Accidental introduction of foreign bodies, such as dental implants, may irritate the maxillary sinus mucosa, causing sinusitis. Cone beam computed tomography (CBCT) has been proven to be suitable for diagnosis in these cases by providing the exact location of the foreign body. The present article reports 3 cases of foreign bodies inside the maxillary sinus associated with inflammatory processes. Imaging examinations, such as CBCT, are an important tool to assist dentists in diagnosing the presence of foreign bodies in the interior of the maxillary sinus.

Correlation between Temperature-dependent Fatigue Resistance and Differential Scanning Calorimetry Analysis for 2 Contemporary Rotary Instruments.

INTRODUCTION: The aim of this study was to assess differences in cyclic fatigue (CF) life of contemporary heat-treated nickel-titanium rotary instruments at room and body temperatures and to document corresponding phase transformations. METHODS: Forty Hyflex EDM (H-EDM) files (Coltene, Cuyahoga Falls, OH [#25/.08, manufactured by electrical discharge machining]) and 40 TRUShape (TS) files (Dentsply Tulsa Dental Specialties, Tulsa, OK [#25/.06v, manufactured by grinding and shape setting]) were divided into 2 groups (n = 20) for CF resistance tests in a water bath either at room (22°C ± 0.5°C) or body temperature (37°C ± 0.5°C). Instruments were rotated in a simulated canal (angle = 60°, radius = 3 mm, and center of the curvature 5 mm from the tip) until fracture occurred. The motor was controlled by an electric circuit that was interrupted after instrument fracture. The mean half-life and beta and eta Weibull parameters were determined and compared. Two instruments of each brand were subjected to differential scanning calorimetry (DSC). RESULTS: While TS instruments lasted significantly longer at room temperature (mean life = 234.7 seconds; 95% confidence interval [CI], 209-263.6) than at body temperature (mean life = 83.2 seconds; 95% CI, 76-91.1), temperature did not affect H-EDM behavior (room temperature mean life = 725.4 seconds; 95% CI, 658.8-798.8 and body temperature mean life = 717.9 seconds; 95% CI, 636.8-809.3). H-EDM instruments significantly outlasted TS instruments at both temperatures. At body temperature, TS was predominantly austenitic, whereas H-EDM was martensitic or in R-phase. TS was in a mixed austenitic/martensitic phase at 22°C, whereas H-EDM was in the same state as at 37°C. CONCLUSIONS: H-EDM had a longer fatigue life than TS, which showed a marked decrease in fatigue life at body temperature; neither the life span nor the state of the microstructure in the DSC differed for H-EDM between room or body temperature.

Cyclic Fatigue Resistance of Heat-treated Nickel-titanium Instruments after Immersion in Sodium Hypochlorite and/or Sterilization.

INTRODUCTION: The purpose of this study was to assess the effects of sodium hypochlorite (NaOCl) immersion and sterilization on the cyclic fatigue resistance of heat-treated nickel-titanium (NiTi) rotary instruments. METHODS: Two hundred ten new 25/.06 Twisted Files (TFs; SybronEndo, Orange, CA) and Hyflex CM (Coltene Whaledent, Cuyahoga Falls, OH) files were divided into 7 groups (n = 15) for each brand. Group 1 (control group) included new instruments that were not immersed in NaOCl or subjected to autoclave sterilization. Groups 2 and 3 were composed of instruments dynamically immersed for 3 minutes in 5% NaOCl solution 1 and 3 times, respectively. Groups 4 and 5 consisted of instruments only autoclaved 1 and 3 times, respectively. Groups 6 and 7 recruited instruments that received a cycle of both immersion in NaOCl and sterilization 1 and 3 times, respectively. Instruments were subsequently subjected to a fatigue test. The surface morphology of fractured instruments was studied by field-emission scanning electron microscopy and x-ray energy-dispersive spectrometric (EDS) analyses. The means and standard deviations of the number of cycles to failure (NCF) were calculated and statistically analyzed using 2-way analysis of variance (P < .05). RESULTS: Comparison among groups indicated no significant difference of NCF (P > .05) except for the groups of TFs sterilized 3 times without and with immersion in NaOCl (P < .05). HyFlex CM files exhibited higher cyclic fatigue resistance than TFs when files were sterilized 3 times, independently from immersion in NaOCl (P < .05). EDS analysis showed the presence of an oxide-rich layer on the Hyflex CM files' external surface. No morphologic or chemical differences were found between files of the same brand subjected to different treatments. CONCLUSIONS: Repeated cycles of sterilization did not influence the cyclic fatigue of NiTi files except for TFs, which showed a significant decrease of flexural resistance after 3 cycles of sterilization. Immersion in NaOCl did not reduce significantly the cyclic fatigue resistance of all heat-treated NiTi files tested.

Comparative Evaluation of Stress Distribution in Experimentally Designed Nickel-titanium Rotary Files with Varying Cross Sections: A Finite Element Analysis.

INTRODUCTION: Single cross-sectional nickel-titanium (NiTi) rotary instruments during continuous rotations are subjected to constant and variable stresses depending on the canal anatomy. This study was intended to create 2 new experimental, theoretic single-file designs with combinations of triple U (TU), triangle (TR), and convex triangle (CT) cross sections and to compare their bending stresses in simulated root canals with a single cross-sectional instrument using finite element analysis. METHODS: A 3-dimensional model of the simulated root canal with 45° curvature and NiTi files with 5 cross-sectional designs were created using Pro/ENGINEER Wildfire 4.0 software (PTC Inc, Needham, MA) and ANSYS software (version 17; ANSYS, Inc, Canonsburg, PA) for finite element analysis. The NiTi files of 3 groups had single cross-sectional shapes of CT, TR, and TU designs, and 2 experimental groups had a CT, TR, and TU (CTU) design and a TU, TR, and CT (UTC) design. The file was rotated in simulated root canals to analyze the bending stress, and the von Mises stress value for every file was recorded in MPa. Statistical analysis was performed using the Kruskal-Wallis test and the Bonferroni-adjusted Mann-Whitney test for multiple pair-wise comparison with a P value <.05 (95 %). RESULTS: The maximum bending stress of the rotary file was observed in the apical third of the CT design, whereas comparatively less stress was recorded in the CTU design. The TU and TR designs showed a similar stress pattern at the curvature, whereas the UTC design showed greater stress in the apical and middle thirds of the file in curved canals. All the file designs showed a statistically significant difference. CONCLUSIONS: The CTU designed instruments showed the least bending stress on a 45° angulated simulated root canal when compared with all the other tested designs.

Low Environmental Temperature Influences the Fatigue Resistance of Nickel-titanium Files.

INTRODUCTION: The purpose of this study was to evaluate the effect of different temperatures (0°C, 10°C, 22°C, 37°C, and 60°C) on the cyclic fatigue life of nickel-titanium (NiTi) files using a new fatigue test model in zirconium oxide. METHODS: Three superelastic NiTi files (EndoSequence [Brasseler USA, Savannah, GA], ProFile [Dentsply Tulsa Dental Specialties, Tulsa, OK], and K3 [SybronEndo, Orange, CA]), and 3 heat-treated (K3XF [SybronEndo], Vortex [Dentsply Tulsa Dental Specialties], and HyFlex CM [Coltene-Whaledent, Allstetten, Switzerland]) NiTi files, all size 25/.04, were subjected to cyclic fatigue tests inside a novel, artificial ceramic canal with a curvature of 60° and a 5-mm radius. The model was immersed in water at 5 different preset temperatures. The number of cycles to failure (NCF) was recorded, and the fracture surface of the fragments was examined by a scanning electron microscope. The data were analyzed using 2-way analysis of variance with the significance level at 0.05. RESULTS: When the temperature was reduced from 60°C to 0°C, the NCF significantly increased from over 2 to 10 times for the NiTi file groups (P < .01). K3XF had the highest fatigue resistance of all files at 0°C (P < .05). Vortex files had the highest NCF at 10°C-60°C. The NCF of heat-treated files was significantly higher than superelastic NiTi files at 10°C and 20°C (P < .05). There was no significant difference in the NCF of HyFlex CM at 0°C and 22°C. There was little difference in the fractographic appearance among different temperatures, except that the fraction area occupied by the dimple region of some instruments at 0°C was slightly smaller than at 60°C. CONCLUSIONS: Cooling down to low temperatures may be an interesting strategy to improve the fatigue resistance of rotary NiTi files.