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Journal: Dental traumatology : official publication of International Association for Dental Traumatology

29

Abstract -  Aim: Experimental materials incorporating fiberglass cloth were used to develop a thin and lightweight face guard (FG). This study aims to evaluate the effect of fiberglass reinforcement on the flexural and shock absorption properties compared with conventional thermoplastic materials. Material and Method: Four commercial 3.2-mm and 1.6-mm medical splint materials (Aquaplast, Polyform, Co-polymer, and Erkodur) and two experimental materials were examined for use in FGs. The experimental materials were prepared by embedding two or four sheets of a plain woven fiberglass cloth on both surfaces of 1.5-mm Aquaplast. The flexural strength and flexural modulus were determined using a three-point bending test. The shock absorption properties were evaluated for a 5200-N impact load using the first peak intensity with a load cell system and the maximum stress with a film sensor system. Results and Conclusions: The flexural strength (74.6 MPa) and flexural modulus (6.3 GPa) of the experimental material with four sheets were significantly greater than those of the 3.2-mm commercial specimens, except for the flexural strength of one product. The first peak intensity (515 N) and maximum stress (2.2 MPa) of the experimental material with four sheets were significantly lower than those of the commercial 3.2-mm specimens, except for one product for each property. These results suggest that the thickness and weight of the FG can be reduced using the experimental fiber-reinforced material.

Concepts: Shock, Materials science, Tensile strength, Material, Pascal, Young's modulus, Thermoplastic, Shock absorber

27

- Primary tooth impaction is a rare phenomenon when compared to permanent teeth impaction. The purpose of this report is to present a 5-year-old Chinese girl who exhibited impaction of tooth 51, its unusual consequence on the permanent successor tooth and its comprehensive management. Her parents revealed that at 6 months of age, the patient had fallen from her bed and struck her face on the floor; however, there were no teeth present in the oral cavity. The intraoral examinations identified a bony-like projection on the buccal aspect of the alveolus in the 51 region. Radiographic examination revealed that tooth 51 exhibited an unfavourable orientation, with the crown directed towards the palate. Therefore, the impacted tooth 51 was surgically removed, and two years later tooth 11 erupted into the oral cavity with an indentation on its incisal aspect, which resembled the crown of the primary teeth, thus giving the appearance of a tooth within a tooth or ‘dens in dente’. Subsequently, enameloplasty and composite resin build-up was performed on tooth 11 for aesthetic reasons. It is very unusual to have the clinical crowns of both primary and permanent teeth in such close proximity within the alveolar bone, and the present case is a good example to emphasize that trauma to the primary teeth is of considerable importance due to the close proximity of the primary teeth to permanent tooth germs.

Concepts: Teeth, Incisor, Maxillary central incisor, Canine tooth, Maxillary lateral incisor, Deciduous teeth, Permanent teeth

24

Facial injury in adults can commonly result in fractures of the mandible. Autologous mesenchymal stem cells (AMSCs) transplantation is proposed as an alternative to conventional graft treatment to improve bone regeneration. The aim was to evaluate the effectiveness of AMSCs application in mandibular fractures to reduce regeneration time and increase bone quality.

Concepts: Clinical trial, Stem cell, Mesenchymal stem cell, Bone marrow, Stem cells, Effectiveness, Pharmaceutical industry, Clinical research

23

In cases of tooth avulsion, a minimal extra-alveolar dry storage period or the use of a suitable storage medium is crucial to maintaining the vitality of the periodontal ligament. Whey has similar properties to milk and has therefore been investigated as a storage medium for avulsed teeth. The aim of the present study was to evaluate the repair process after replantation of rat teeth kept in whey and whole milk.

Concepts: Whey protein, Milk, Cattle, Periodontal ligament, Whey

1

0

Traumatic dental injuries (TDIs) account for a considerable proportion of bodily injuries. Nevertheless, global TDI frequency is unknown, probably because TDI diagnosis is not standardized. This study estimated world TDI frequency. A literature search (publication years 1996-2016) was aimed at covering as many countries, communities, ethnic groups as possible, thus achieving high generalizability. In particular, nonspecific keywords, no language restrictions and large databanks were used. Observational studies reporting proportions of individuals with at least one TDI (prevalence) and who developed TDI (incidence rate) were considered. Prevalence rates to permanent dentition, primary dentition and in 12-year-olds, incidence rate to any tooth for any age, male-to-female prevalence ratio (PR) in 12-year-olds, with 95% confidence intervals (95CIs), were extracted/calculated. Study quality, Z-score distribution, funnel plot symmetry analysis, between-study heterogeneity, sensitivity and subgroup analyses were performed. Selected primary studies were 102 (permanent dentition; 268,755 individuals; median age, 13.8 years), 46 (primary dentition; 59,436 individuals; median age, 3.4 years), 42 (12-year-olds; 33,829 individuals), 11 (incidence rate; 233,480 person-years; median age, 7.8 years), 31 (PR; 16,003 males, 16,006 females). World TDI frequency resulted: permanent dentition prevalence 15.2% (95CI, 13.0-17.4%); primary dentition prevalence 22.7% (95CI, 17.3-28.7%); 12-year-olds prevalence 18.1% (95CI, 15.3-21.0%); incidence rate, 2.82 (95CI, 2.28-3.42) per 100 person-years; PR, 1.43 (95CI, 1.34-1.52). Differences between WHO Regions were found. This study shows that more than one billion living people have had TDI. TDI is a neglected condition which could rank fifth if it was included in the list of the world’s most frequent acute/chronic diseases and injuries. This article is protected by copyright. All rights reserved.

Concepts: Epidemiology, Medical statistics, Incidence, Normal distribution, Teeth, Prevalence, Copyright, Denominator data

0

In Lithuania, dental trauma cases are also treated by general dentists but it is unknown whether their age, self-evaluation of trauma knowledge and practice location can predict their actual knowledge and management of trauma cases. The aim of this study was to evaluate whether these factors can be used to predict the actual knowledge and management of trauma cases.

Concepts: Scientific method, Psychological trauma, Teeth, Dental implant, Dentistry, Vilnius, Lithuania

0

The mouthguard (MG) is an effective device to reduce the risk of dental traumatic injuries but the mechanical effects of wearing a MG and its design are not fully understood. The aim of this study was to evaluate the mechanical influence of wearing a MG and its palatal design on the tooth-periodontal ligament-bone complex (TPBC) by computational analysis using the finite element method.

Concepts: Hydrogen, Engineering, Finite element method, Hilbert space, Injury, Computational fluid dynamics, Partial differential equation, Numerical analysis

0

Ice hockey players of all ages experience oral and dental injuries. The Aim of this study was to evaluate the rates of ice hockey related oral injuries, time lost due to oral injury and mechanisms of oral injuries in the province of Alberta during a 15 year period (2001-2016).

Concepts: Alberta, Provinces and territories of Canada, Canada, Ice hockey, Montreal, Edmonton, Calgary

0

A newly developed powdered coconut water formulae (ACP-404) has been proposed to preserve periodontal ligament cell viability. The aim of this study was to investigate the periodontal healing of dog teeth replanted after storage in ACP-404 with two different osmolalities.

Concepts: Periodontal ligament