Oro-dental trauma burden and mouthguard usage among contact sports players: A call for sports dentistry initiatives in Sri Lanka.

BACKGROUND/AIM: Contact sports-related oro-dental trauma contributes to a significant proportion of sports injuries among school children. Oro-dental trauma imposes a detrimental impact on the oral health-related quality of life. However, the burden of oro-dental trauma among contact sports players and their practices of mouthguards remains a research gap in Sri Lanka. The current study bridges that while providing evidence for contextual changes such as initiating sports dentistry. MATERIALS AND METHODS: The study was conducted among 1340 adolescent contact sports players in Colombo district, Sri Lanka; 63.1% males and 36.9% females (age 13-18), who were enrolled in football, rugby, hockey, boxing, basketball, and martial arts in the school setting. A checklist was administered to obtain demographic information, sports practices, and the use of mouthguards. An oral examination was conducted for those who experienced oro-dental trauma during the last 12 months. RESULTS: Self-reported oro-dental trauma pooled prevalence of the contact sports players was 35.9% (95% CI = 33.3-38.5), with males' preponderance. Dental trauma was present in 23.8% (n = 319), while 15.8% were uncomplicated and 8% were complicated. Soft tissue injuries were present in 12.1% (n = 162). Oro dental trauma (ODT) was highly prevalent among boxing, rugby, and hockey players. Only 20.8% (n = 279) of players used mouthguards. However, 91.0% (n = 254) of them were using ready-made mouthguards. Mouthguard use and the type of mouthguard showed statistically significant associations across the type of oro-dental trauma among contact sports players. CONCLUSIONS: Contact sports-related oro-dental trauma prevalence is as high as 35.9% among Colombo district school children in Sri Lanka. However, their level of mouthguard usage is shallow at 20.8%. Further research is necessary to investigate the reasons behind this, and national guidelines should be developed to prevent and manage sports-related accidental injuries.

Performance of a novel self-adhesive bulk-fill composite hybrid in endodontically treated maxillary premolars: analysis of fracture resistance and failure mode.

This study evaluated the fracture resistance of endodontically treated maxillary premolars restored with a new self-adhesive composite hybrid material (Surefil one [SO]) using different protocols. A total of 72 maxillary premolars were divided into 6 groups (n = 12). The control group included intact teeth, and the other 5 groups included teeth in which disto-occlusal cavities were prepared and endodontic treatment was performed. The prepared cavities were assigned to groups that were based on the restorative procedures: bulk-fill group, universal adhesive plus conventional bulk-fill composite resin plus a layer of conventional composite resin; SO-SC group, self-cured SO; SO-LC group, light-cured SO; SO-UA group, universal adhesive plus SO; or SO-core group, a 4.0-mm layer of SO covered by a layer of conventional composite resin. Specimens in each group underwent thermocycling and load cycling to test the fracture strength and fracture mode. The results were analyzed using analysis of variance and the Tukey test (α = 0.05). The SO-core group showed the highest mean (SD) fracture resistance, 959.9 (171.8) N, among the restored groups. The SO-core group did not differ significantly from the control group (P > 0.05) but did show significantly higher strength than all other test groups (P < 0.05) except SO-SC (P = 0.364). No significant differences were found between the bulk-fill, SO-SC, SO-LC, and SO-UA groups (P > 0.05). The SO-core group showed the highest number of unrestorable fractures, while the main fracture mode for the other groups was restorable fracture. Although the use of SO as a core material restored the fracture strength of endodontically treated premolars to the level of intact teeth, it also resulted in a higher incidence of unrestorable fractures. The SO-SC group demonstrated a high fracture resistance comparable to that of the SO-core group and had a greater tendency to experience restorable fractures.

Enamel chipping and its ecological correlates in African papionins: Implications for hominin feeding behavior.

African papionins are classic paleoecological referents for fossil hominins. Enamel chips on the teeth of baboons and hominins are argued to represent responses to similar dietary habits; however, a comprehensive analysis of modern papionin chipping is lacking, leaving open the question of analog suitability. Here, we investigate patterns of antemortem enamel chipping across a diverse set of African papionin species occupying a range of ecological niches. We compare papionin chipping frequencies to estimates for Plio-Pleistocene hominins to address hypotheses of habitat and/or dietary similarities. Antemortem chips in seven African papionin species were scored on intact postcanine teeth (P3-M3) using established protocols. Chip size was scored on a tripartite scale. Papio hamadryas and Papio ursinus-two common paleoecological referents-display higher levels of chipping than Plio-Pleistocene hominin taxa (Australopithecus and Paranthropus) posited to have similar dietary habits. Papio populations occupying dry or highly seasonal habitats accumulate more large chips than Papio taxa occupying more mesic habitats, and terrestrial papionins chip their teeth more often than closely related taxa occupying arboreal niches. Chipping is present on the teeth of all Plio-Pleistocene hominins; however, chipping in baboons (P. ursinus and P. hamadryas) consistently exceeds most hominin taxa. Chipping frequencies on their own do not reliably sort taxa into major dietary groupings. We conclude that the large differences in chipping frequency may instead reflect habitat use and food processing idiosyncrasies. Less chipping in Plio-Pleistocene hominin teeth compared to modern Papio is more likely attributable to differences in dental morphology rather than diet.

Influence of the technical parameters of CBCT image acquisition on vertical root fracture diagnosis: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the influence of image acquisition parameters (voxel, FOV, kVp, mA) on the accuracy of cone-beam computed tomography (CBCT) in detecting vertical root fracture (VRF). MATERIAL AND METHODS: Searches were performed in 6 main databases and the gray literature, without restrictions of language or date. Observational clinical studies (OCS) and in vitro-extracted teeth (IV) studies were considered eligible for inclusion when investigating the accuracy (sensitivity, specificity) of CBCT in detecting VRF in human teeth. The risk of bias was assessed using QUADAS-2, and a meta-analysis was performed using Review Manager v5.4 software and Jamovi software v1.6. RESULTS: A total of 60 out of 132 articles was included after fulfilling the eligibility criteria. Of these, 54 were IV studies while 6 were OCS. In the IV studies, it was seen that smaller FOV sizes tended to present higher accuracy values. The meta-analysis of the 6 OCS showed that the overall sensitivity and specificity values for 0.08 mm and 0.1 mm voxels were greater (0.84 and 0.79, respectively) than the sensitivity and specificity values for 0.125 mm and 0.2 mm voxels (0.70 and 0.55, respectively). CONCLUSIONS: Despite the uncertain risk of bias found for the IV and OCS studies, smaller voxel and FOV sizes seem to provide more accurate VRF detection values when using CBCT. CLINICAL RELEVANCE: This information is crucial for supporting the clinician when prescribing CBCT in cases of a clinical suspicion of VRF, and contributes to the personalization of the CBCT prescription, thereby ensuring greater accuracy in the VRF diagnosis. Registration This protocol was registered at the PROSPERO database (International Prospective Register of Systematic Review) under registration number CRD42020210118.

Influence of sharpening filters on the detection of root fractures using low-dose cone-beam computed tomography.

OBJECTIVES: To evaluate the influence of sharpening filters in the detection of root fractures using low-dose cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Eighty-four CBCT volumes acquired at three mA levels of 28 teeth inserted in the dental socket of dry human skull were selected from a previous study. The teeth were divided into four groups according to the presence and absence of root fracture and endodontic filling. Five radiologists evaluated all CBCT volumes for the presence of root fracture with and without the application of "Sharpen 1x" and "Sharpen 2x" filters in OnDemand3D software. Area under the ROC curve (AUC), sensitivity, specificity, and inter- and intra-observer concordance were calculated and compared (α = 0.05). RESULTS: Sharpening filters did not lead to significant differences in AUC, sensitivity, and specificity at the three mA levels tested (p > 0.05), regardless of the presence of endodontic filling (p > 0.05). However, the significant reduction of AUC observed in CBCT volumes at 4 mA without filter (p < 0.05) ceased to exist after the application of filters (p > 0.05). Sensitivity and specificity ranged from low and moderate. CONCLUSIONS: The use of sharpening filters can be recommended in CBCT volumes at 4 mA for root fracture detection for leading to the same performance as those at 6.3 and 10 mA. The presence of endodontic filling material did not influence the action of filters in the diagnosis of root fracture. CLINICAL RELEVANCE: Sharpening filters seem to contribute to the diagnosis of root fracture in CBCT volumes acquired with reduced radiation dose.

Are yellow-brownish opacities in hypomineralized teeth more prone to breakage than white-creamy ones? A systematic review.

OBJETIVE: To evaluate all the available evidence assessing if in hypomineralized teeth, yellow-brownish opacities are more prone to post-eruptive breakdown (PEB) compared to white-creamy opacities. MATERIALS AND METHODS: Observational studies that evaluated the occurrence of PEB in hypomineralized teeth were considered for inclusion. Electronic searches were performed up to January 2022 in MedLine, LILACS, BBO, Cochrane Library, Web of Science, Scopus, and EMBASE. Neither publication date nor language restrictions were imposed to the searches. Two researchers independently performed the study selection, data extraction, and quality assessment of the included studies according to the Newcastle-Ottawa Scale (NOS). Datasets from studies were grouped for narrative synthesis based on the severity of the PEB (enamel or dentin), type of tooth (molar or incisor), unit of analysis (subject or tooth or tooth surface), and follow-up period (in months). The certainty of evidence was evaluated using the GRADE approach. RESULTS: Nine studies were included, five cohort and three cross-sectional. All studies assessed the opacities and PEB by visual examination and diagnosed MIH according to EAPD criteria. In the cohort studies, considering all follow-up periods (ranging from 6 to 36 months), dark opacities fractured more than light opacities, at both enamel and enamel/dentin levels, and molars fractured more than incisors. In two out of three cross-sectional studies, dark opacities also fractured more than light opacities, but the deep of the PEB (enamel or dentin breakdown) or the type of tooth (molar or incisor) was not considered in the analysis. CONCLUSION: Although it seems plausible to state that darker demarcated opacities in MIH patients broke more often than light ones, based on this systematic review of the literature, the certainty of the available evidence about this association is still very low. CLINICAL RELEVANCE: More reliable and valid research is still necessary to support any future recommendation that MIH children who present yellow-brownish opacities should be monitored at shorter intervals compared to those who present only white-creamy opacities.

Trends and seasonality in public interest in dental trauma: Insights from Google Trends.

AIM: To assess trends and seasonal variation of dental trauma by using the Google Trends data. DESIGN: Google Trends was used to obtain relative search volume (RSV) of search terms such as dental trauma, broken tooth, chipped tooth, knocked-out tooth, avulsed tooth, and gum trauma. The search strategy was set to the time period (January 2004 to December 2019), region (worldwide, the United States, the UK, Australia, Canada, New Zealand, Ireland, and Turkey), Web search, and all categories. Seasonal variation was evaluated using the cosinor analysis. RESULTS: The worldwide RSV values of broken tooth, chipped tooth, knocked-out tooth, and avulsed tooth have shown a general increase in recent years with an upward forecast line. The RSV values of dental trauma have shown a general increase in recent years with a plateau forecast line, and gum trauma has shown a stable trend with a plateau forecast line. Seasonal variation of chipped tooth, broken tooth, dental trauma, knocked-out tooth, avulsed tooth, and gum trauma was not found statistically significant in any of the countries (p > .025). The top related queries of chipped tooth and broken tooth were about pain, fix/repair, and cost. The top related topics for avulsed tooth and knocked-out tooth are about infant, child, toddler, and primary tooth. CONCLUSIONS: People's interest on dental trauma, broken tooth, chipped tooth, knocked-out tooth, and avulsed tooth has shown a general increase in recent years without showing a seasonal pattern. Healthcare professionals should pay more attention to people's concerns and informational needs.

Tooth chipping prevalence and patterns in extant primates.

OBJECTIVES: A tooth chip occurs when a hard object forcefully contacts the surface of the tooth, typically removing enamel from the occlusal edge. In this study, chipping patterns in extant primates were compared, and hard-object-feeding assessed alongside other factors (e.g., grit mastication and dental properties), to elucidate dietary and behavioral inferences in archeological and paleontological samples. MATERIALS AND METHODS: Thirteen species of extant primates were studied, including eight species within the Cercopithecidae, two within the Ceboidea, and three within the Hominoidea. Four additional species were also incorporated from the literature for some of the analyses. The severity (Grade 1-3), position (buccal, lingual, mesial, and distal) and number of tooth fractures were recorded for each specimen. RESULTS: Species considered hard-object-feeding specialists presented higher rates of chipping, with sakis, mandrills, sooty mangabeys and Raffles' banded langurs having high chipping rates (28.3%, 36.7%, 48.4%, and 34.7% of teeth, respectively). Species that seasonally eat harder foods had intermediate chipping frequencies (e.g., brown woolly monkeys: 18.5%), and those that less commonly consume hard food items had the lowest chipping frequencies (e.g., Kloss gibbon: 7.3%; chimpanzees: 4.4%). DISCUSSION: The results suggest hard food mastication influences differences in chipping prevalence among the species studied. Although Homo fossil samples show high rates of chipping comparable to hard-object-feeding extant primates, they display a different pattern of chipping, supporting the hypothesis that these fractures are mostly non-food related (e.g., grit mastication in Homo naledi; non-masticatory tooth use in Neanderthals).

Influence of metal artefact reduction tool on the detection of vertical root fractures involving teeth with intracanal materials in cone beam computed tomography images: A systematic review and meta-analysis.

BACKGROUND: The effectiveness of the metal artefact reduction (MAR) tool for the detection of vertical root fracture (VRF) by cone beam computed tomography (CBCT) images is controversial. OBJECTIVE: To evaluate the effectiveness of the MAR tool on VRF detection involving teeth with intracanal materials in CBCT images. METHODOLOGY: In September 2019, an electronic search was performed in six databases (PubMed, Scopus, Web of Science, Cochrane, Lilacs and Embase). The electronic search was updated in May 2020 through searches in Google Scholar and references of included studies (embracing the electronic and gray literature searches). No language or year restrictions were applied. Independently, two reviewers examined titles, abstracts and full texts according to the eligibility criteria that were as follows: diagnostic studies that evaluated the effectiveness of the MAR tool on the diagnosis of VRF in human teeth (laboratory or in vivo studies) on CBCT images. The risk of bias was evaluated using the Quality Assessment Tool for Diagnostic of Accuracy Studies-2 (QUADAS-2). For conducting the meta-analysis, the values of sensitivity, specificity, diagnostic odds ratio (DOR) and area under the ROC curve (AUC) were obtained, considering the subgroups with and without MAR active. The Grading of Recommendation, Assessment, Development and Evaluation instrument was applied to assess the level of evidence across the studies using GRADEpro software. RESULTS: A total of 8 laboratory studies were included in both systematic review and meta-analysis. The values of sensitivity, specificity, DOR and AUC to VRF diagnosis with and without MAR active were, respectively, 0.586 and 0.603; 0.699 and 0.713, 3.037 and 3.767; 0.67 and 0.71. The quality of the evidence suggested low confidence in estimating the outcomes. DISCUSSION: The MAR tool decreased slightly the diagnostic values of VRF involving teeth with intracanal materials in laboratory studies. However, it is important to highlight that most studies had an uncertain risk of bias. CONCLUSIONS: Although a low level of evidence and high heterogeneity were observed in the included studies, the meta-analysis revealed better diagnosis values for VRF detection when the MAR was deactivated when analysing extracted teeth in a laboratory setting. REGISTRATION: PROSPERO-CRD42020145222. FUNDING: This study was financed in party by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES).

Influence of glass fiber posts on the fracture susceptibility of endodontically treated maxillary anterior teeth with direct veneers: Preliminary results of a randomized clinical trial.

OBJECTIVE: The purpose of this randomized clinical trial was to evaluate the influence of glass fiber posts on fracture susceptibility of endodontically treated maxillary anterior teeth with direct veneers. MATERIALS AND METHODS: Fifty participants had 1 maxillary anterior tooth restored with a direct veneer. They were divided into 2 groups (n = 25) according to the use of intraradicular glass fiber posts. Clinical evaluation was performed at baseline, 6 and 12 months. The treatment success was determined by the absence of tooth fracture. If there was fracture, it was classified according to its extent. Fischer exact test was performed to analyze the criteria among the groups at each evaluation time. Friedman repeated analysis of variance assessed the difference in the performance of each group at three recall times (α = 0.5). RESULTS: For control group, at the 6-month follow-up, one tooth had suffered a catastrophic failure, which resulted in tooth extraction. Fisher statistical analysis showed no significant difference between the cumulative success rate of the groups for the 6 (P > .999) and the 12-month (P > .999) period. Friedman test showed no significant difference among the periods of evaluation (P > .999). CONCLUSIONS: Both groups had a similar success rate for maxillary anterior endodontically treated teeth with direct veneers after 12 months. CLINICAL IMPLICATIONS: Glass fiber post use does not influence the fracture susceptibility of maxillary anterior endodontically treated teeth with direct veneers in the short term.

Effect of ferrule height and distribution on the fracture resistance of endodontically treated premolars.

OBJECTIVE: To evaluate the effect of varying ferrule height and distribution on the fatigue resistance and fracture strength of endodontically treated premolars. MATERIALS AND METHOD: Thirty-two extracted human premolars were endodontically treated and prepared to receive all-ceramic crowns. Teeth were randomly divided into two groups. The occluso-cervical height was reduced to 2 mm and 4 mm for the 1st and 2nd groups, respectively. According to the ferrule distribution, samples in each group were randomly divided into two subgroups with inadequate ferrule on 1 or 2 proximal walls, respectively. Coronal tooth structure was built-up to 4 mm using a core build-up material retained by a fiber post. The CEREC system (Sirona) was used to design and mill lithium-disilicate crowns. All posts and crowns were cemented to their respective teeth using self-adhesive universal resin cement. All crowns were subjected to cyclic loading in a universal testing machine (Instron) (20-100N, 100,000 cycles, 20Hz). After fatigue, crowns were loaded to fracture. Fracture load data were analyzed using two-way ANOVA at α = 0.05. RESULTS: All crowns passed the fatigue testing without any signs of fracture or crack. Two-way ANOVA revealed a statistically significant effect of the number of missing walls (P < 0.05) on the fracture load, but not the ferrule height or the interaction terms. Samples with one missing wall showed higher fracture load in comparison to samples with two missing walls. CONCLUSION: The number of missing walls, not the ferrule height, has a significant effect on the fracture load of the lithium-disilicate crowns restoring endodontically treated premolars.

Orthograde apical plug in a traumatized tooth with necrotic pulp and immature apex using calcium silicate cement: A case report.

This case report describes dental management of a 15- year-old boy, undergoing treatment for Thalassaemia Major and Acute Myeloid Leukaemia with bone marrow transplant and immuno-suppressants. During the course of his treatment the patient developed a swelling in anterior maxilla and therefore was referred by the primary physician for evaluation. This case report highlights the management of medically compromised patients in a tertiary care hospital in which apexification was carried out in a permanent immature tooth utilizing MTA as an immediate apical plug.

Forensic Analysis of 41 Traumatic Tooth Fracture Cases.

ABSTRACT: Objective To discuss the types, number and diagnostic methods of traumatic tooth fracture in order to provide reference for forensic clinical identification. Methods The 41 cases accepted by Judicial Appraisal Center of Gansu University of Political Science and Law from January 2015 to December 2017, were analyzed by descriptive statistics according to information such as the basic situation, injury manner, type and number of tooth fracture, diagnostic method and expert opinion. Results The 41 cases included 31 males and 10 females. Tooth fracture occurred mainly on the maxillary anterior teeth. The main injury manner of traumatic tooth fracture was collision injury. CT scan improved the accuracy of diagnosis. Conclusion There are gender differences in tooth fracture cases. The part of fracture is related to tooth anatomical characteristics. CT scan can be a priority in tooth fracture diagnosis. Forensic analysis of traumatic tooth fracture should comprehensively consider the types and number of tooth fracture, and define the relationship between tooth fracture and the injury.

Dental Pathology of the Iberian Lynx ( Lynx pardinus), Part I: Congenital, Developmental, and Traumatic Abnormalities.

The Iberian lynx is an endangered felid that has been subject to an intensive ongoing conservation program in an attempt to save it from extinction. Identification of dental pathologies could play an important role in the survival of this endangered species. The objective of this study is to evaluate the dental pathologies (congenital, developmental, and traumatic abnormalities) of this species of felid. Skulls of 88 adult specimens of the Iberian lynx ( Lynx pardinus) from the Doñana Biological Station [Estación Biológica de Doñana-Consejo Superior de Investigaciones Científicas] (EBD-CSIC), Seville, Spain, were examined macroscopically, and full-mouth dental radiographs of all specimens were performed. Presence, absence, form of teeth, number of roots, supernumerary teeth, and persistent deciduous teeth were evaluated. The presence of attrition/abrasion, tooth fractures, enamel hypoplasia/hypomineralization, endodontic disease, intrinsically stained teeth, and other traumatic findings were also evaluated. Abnormal grooves and dilacerations were the most common abnormalities seen in the roots of teeth. Two hundred and fifteen fractured teeth (11.3% of evaluated teeth) were detected, and mainly complicated fractures were noted in maxillary canine teeth (24.2% of fractured teeth) and mandibular canine teeth (16.7% of fractured teeth). Endodontic disease was present in 3.9% of the teeth examined. Intrinsic tooth staining was assessed in 8.5% of evaluated teeth. Of all teeth examined, 831 teeth (43.7% of evaluated teeth) exhibited some type of attrition/abrasion. Our study concluded that there is a high prevalence of dental fractures and attrition/abrasion with associated endodontic disease that could lead to impaired hunting ability as well as a threat to overall health and subsequent survival of this endangered species.

Diagnoses and Treatment of Dental Disorders in a Research Colony of Macaca fascicularis: A Case Series.

During daily routine oral examinations in a research colony of nonhuman primates (NHPs, Macaca fascicularis), a variety of oral-dental lesions were identified. A dental care program was established based on these findings. Based on the presence of dental clinical signs and their severity, 31 animals were triaged to be examined and treated by a veterinarian. Clinical examination consisted of visual inspection using a periodontal probe/explorer and full or partial mouth dental radiographs. Treatment was performed during the same procedure. Some animals had a follow-up examination including radiographs months later. Four common dental diseases were diagnosed: periodontal disease, caries, tooth fracture, and tooth attrition. Less frequent were dental abscess, enamel hypomineralization, gingival hyperplasia, hypercementosis, tooth luxation, tooth dysplasia, root resorption, abrasion. Less severe periodontal disease was treated conservatively. If severely affected, teeth were extracted. Well-circumscribed caries without endodontic involvement were treated by composite restoration. Teeth with extensive caries and pulp involvement were extracted. Teeth with exposed pulp were treated via extraction or orthograde root canal treatment. In this case series, 27 (87%) of 31 NHPs exhibited at least 1 moderate to severe dental lesion that required treatment. The presumable improvement in welfare and weight of oral/dental lesions for the overall health status in research NHPs encourages us to continue this program prospectively.

Digital radiographs displayed on different devices: effect on the detection of vertical root fractures.

AIM: To evaluate whether the type of display device affects the detection of vertical root fractures (VRFs) on digital radiographs in unfilled canals and canals with fibreglass posts. METHODOLOGY: Forty single-rooted human teeth were decoronated, and the root canals were prepared. The teeth were divided into 2 groups: controls (20 teeth) and with VRF (20 teeth). The VRFs were induced using an universal testing machine. Periapical radiographs of all teeth, with canal unfilled or with a fibreglass post, were obtained using the parallel technique in 3 directions (ortho-, mesio- and distoradial) on storage phosphor plates (VistaScan®). All images were evaluated and re-evaluated after 30 days by 3 examiners on a 5-point scale using 4 different devices (notebook display with full high definition resolution, desktop display with a standard resolution, 8-inch Android(™) tablet with high definition resolution and a 9.7-inch iPad® tablet with Retina resolution). Areas under ROC curves, sensitivity, specificity and accuracy values were compared by anova. RESULTS: The weighted kappa values for intra- and interobserver reproducibility were 0.55-0.88 and 0.31-0.65, respectively. There was a significant difference (P < 0.05) in relation to the area under the ROC curve, specificity and sensitivity when unfilled canals were compared with canals with a fibreglass post; however, no difference was observed for the different devices studied. CONCLUSIONS: The type of display device did not affect the detection of VRFs. Thus, the detection of VRFs can be performed using different screen sizes and resolutions.

Effect of chewing speed on the detection of a foreign object in food.

Accidentally biting hard on a piece of hard foreign object in food is among the causes of tooth fracturing and could be associated with oral sensibility. This study has investigated the effect of chewing speed on the ability to detect a foreign object in food in human. Fourteen healthy subjects were asked to randomly chew one of 10 cooked rice balls, five of which containing a foreign object made from a tiny uncooked rice grain, until they detected the rice grain. Each subject chewed the test foods both at 50 (slow) and 100 (fast) chews min(-1). The accuracy of detection and the number of chews before detection (CBD) were recorded and compared between the two chewing speeds using paired t-tests. The results showed that almost all subjects detected the foreign object by biting. The accuracy of detection was more than 90% and not significantly different between slow and fast chewing but the mean CBD in slow chewing (11·7 ± 1·3 chews) was significantly different from that in fast chewing (20·7 ± 1·9 chews; P < 0·001). The study showed that slow chewers required less number of chews before a foreign object in food could be detected and was, presumably, more effective in detecting the object compared to fast chewers. If each chew bears equal probability of teeth encountering the foreign object, slow chewing might also reduce the chance of accidentally biting hard on the foreign object and fracturing the tooth.

The influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures.

AIM: Line pairs are the unit for measurement of resolution and are related to the spatial quality of the system. Thus, the objective of this study was to evaluate the influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures. MATERIALS AND METHODS: Sixty-four extracted single-root human teeth were used. Thirty-two had horizontal root fractures created and were mounted in dry human mandibles. The teeth were radiographed with two digital receptors: the Digora Optime (14.3 lp mm-1) and the Digora Toto (26.3 lp mm-1). Images were viewed under standardized conditions by 3 calibrated examiners using the respective dedicated software (Digora for Windows 2.6(®) and Scanora(®) ). Digora Toto(®) images were also evaluated through the Digora for Windows 2.6(®) software. The results were statistically analyzed based on the area under the ROC curve for each examiner. RESULTS: Pairing Digora Toto(®) with Scanora(®) allowed for greater accuracy in horizontal root fractures diagnosis, while images acquired with that same system seem to lose accuracy when visualized with Digora for Windows 2.6(®) . Pairing Digora Optime(®) with Digora for Windows 2.6(®) resulted in the lowest accuracy for horizontal root fractures diagnosis. CONCLUSIONS: The higher number of line pairs and the consequent higher image resolution provided by the Digora Toto(®) system and its dedicated software seem to enhance the accuracy of horizontal root fractures diagnostic imaging.

Historical Perspectives IV: Creative Management of Fractured Teeth.

Various contemporary efforts have been advocated to strengthen root-treated teeth to prevent fracture; or to manage teeth that exhibit fractures. These efforts have favored the use of newer, adhesive materials, incorporating horizontally transfixed fiberglass posts to stabilize the fractured segments. Results have been encouraging, as teeth tested have exhibited fracture resistance similar to that found with onlays. However, this concept is not new and in spite of not having the advantages of adhesive dental materials, including the fiberglass posts, efforts that were made close to 100 years ago to stabilize and retain fractured teeth were reasonably successful.

Impact of root fillings and posts on the diagnostic ability of three intra-oral digital radiographic systems in detecting vertical root fractures.

AIM: To evaluate (i) the accuracy of three intra-oral digital systems in detecting vertical root fractures (VRFs); and (ii) the influence of different intracanal conditions (without filling, filled with Gutta-percha and metal or fibreglass post). METHODOLOGY: Forty single-rooted human teeth were decoronated and the root canals prepared. VRFs were induced using a universal testing machine on 20 teeth. Radiographic images were obtained using the paralleling technique with three different horizontal angulations on conventional E/F film, two storage phosphor plates (Digora Optime and VistaScan) and one sensor system (SnapShot). All teeth were radiographed with all intracanal conditions tested. All images were evaluated by five examiners. After 30 days, 25% of the images were reviewed. Areas under ROC curves, sensitivity, specificity, accuracy, positive predictive and negative predictive values were compared by anova. RESULTS: The weighted kappa values for intra- and interobserver reproducibility were 0.48-0.74 and 0.57-0.66, respectively. The sensitivity revealed a significant difference between imaging modalities, with higher values for SnapShot (0.53) and VistaScan (0.46), followed by the film (0.41) and Digora (0.38). The area under the ROC curve for SnapShot (0.82) was greater than for the other systems in the teeth with a fibreglass post (VistaScan: 0.70; Digora: 0.64; film: 0.60). CONCLUSION: All systems gave a similar performance for detecting VRFs; all gave a good performance in the absence of intracanal materials, but performed less well in the presence of a metal post or Gutta-percha. In teeth with a fibreglass post, digital systems with higher resolution should be used.