Thinning factors influence on custom‐made mouthguards thermoforming

The aim of this study was to clarify and quantify factors influencing thinning during a thermoforming using a special simulation model that has three different flat surfaces such as 0 degree, 45 degree and 90 degree against a pressurizing force. Air pressure type samples were made by EVA and acrylic resin blank. Vacuum type samples were also made by EVA. Thickness gauge was employed to measure the thickness. As results, pressure forming showed significantly larger thinning at 45 and 90 degree surfaces and smaller thinning at 0 degree surface, 36% in thinning rate by vacuum forming and 66% by the pressure forming at 90 degree surface, and 17% and 20% at 45 degree surface, and 11% and 2% at 0 degree surfaces. Thinning was increased with the increase in distance from the centre in 0 degree surface and increased with the decrease in height in the vertical surface significantly. The air pressure, the material thickness in EVA (Drufosoft) and difference in material colour did not affect thinning rate. An acrylic resin material showed approximately 10% smaller thinning than EVA (Drufosoft). To retain enough thickness of 3 mm on 90 degree surface corresponding to an incisal labial aspect for pressure laminate type, over 55% reduction is taken into consideration and at least two 3‐mm‐thickness materials should be laminated. 0 degree surface showed at most 2 % reduction in pressure lamination; post thermoforming occlusal thickness became almost 6 mm with a usual 3 mm plus 3 mm lamination. Therefore, careful occlusal adjustment in an actual mouthguard fabrication to achieve an appropriate 2 mm thickness on this surface should be requested.     

The linear shade guide design of Vita 3D‐master performs as well as the original design of the Vita 3D‐master

Summary Visual tooth colour assessment by use of the Vita 3D‐Master^® (3D; Vita Zahnfabrik, Bad Säckingen, Germany) is well documented. To improve handling, a new linear arrangement of the shade tabs has been introduced (LG; Linearguide 3D‐Master^®). The purpose of this study was to investigate whether the linear design has an effect on shade matching. Fifty‐six students underwent identical, theoretical and practical training, by use of an Internet learning module [Toothguide Training Software^® (TT)] and a standardised training programme [Toothguide Training Box^® (TTB)]. Each student then matched 30 randomly chosen shade tabs presented in an intra‐oral setting by a standardised device [Toothguide Check Box^® (TCB)]; 15 matches were made using the 3D and 15 using the LG shade guide system, under a daylight lamp (840 matches for each guide). It was recorded to what extent the presented and selected shade tabs, or the lightness group of the tabs, matched, also the needed time for colour matching. The results showed that 35% of perfect matches were observed for the 3D and 32% for the LG. The lightness group was correct in 59% of cases for 3D and 56% for LG. Mean time needed for matching of tabs and lightness group was no different between groups (no significant difference for any assessment). Within the limitations of the study design, the colour assessment with regard to performance and time needed in shade matching was not different with the LG or the 3D. Therefore, the user should choose which shade tab arrangement is more applicable.     

Do custom‐made mouth guards have negative effects on aerobic performance capacity of athletes?

Abstract –  Mouth guards are considered an essential part of equipment for athletes participating in contact sports. The purpose of this study was to evaluate the effect of custom-made mouth guards on the ventilatory gas exchange effects of taekwondo athletes. The subjects were 22 elite athletes aged between 14 and 17 years. To determine the effect of mouth guard use during exercise, oxygen consumption (VO₂) was measured with a portable gas analysis system while an exercise tolerance test with a shuttle run test protocol was performed. Values with and without mouth guard were compared. Wilcoxon ranks test was used for the statistical analysis. The results show that wearing mouth guards has no significant effect on maximal oxygen uptake (VO_2max), minute ventilation (VE), tidal volume (VT) and respiratory exchange ratio (RER) while performing maximal exercise ( P  > 0.05). In conclusion, taekwondo athletes can use custom-made mouth guards without negative effects on their aerobic performance capacity.     

3D printed simulation models based on real patient situations for hands‐on practice

During the last few years, the curriculum of many dentistry schools in Germany has been reorganised. Two key aspects of the applied changes are the integration of up‐to‐date teaching methods and the promotion of interdisciplinarity. To support these efforts, an approach to fabricating individualised simulation models for hands‐on courses employing 3D printing is presented. The models are based on real patients, thus providing students a more realistic preparation for real clinical situations. As a wide variety of dental procedures can be implemented, the simulation models can also contribute to a more interdisciplinary dental education. The data used for the construction of the models were acquired by 3D surface scanning. The data were further processed with 3D modelling software. Afterwards, the models were fabricated by 3D printing with the PolyJet technique. Three models serve as examples: a prosthodontic model for training veneer preparation, a conservative model for practicing dental bonding and an interdisciplinary model featuring carious teeth and an insufficient crown. The third model was evaluated in a hands‐on course with 22 fourth‐year dental students. The students answered a questionnaire and gave their personal opinion. Whilst the concept of the model received very positive feedback, some aspects of the implementation were criticised. We discuss these observations and suggest ways for further improvement.     

Custom Nasal Septum Prosthesis Fabricated from a 3D‐Printed Working Model: A Clinical Report

This clinical report describes the treatment of a 47‐year‐old female patient with a nasal septum perforation. The treatment used a 2‐piece magnetic custom prosthesis fabricated from a 3D‐printed model. By using an existing medical CT scan to generate the printed working model, the number of clinical appointments was reduced. The workflow expanded the purpose of the radiologic images from simply diagnostic to include the prosthetic aspect of treatment.     

DEEP Study: does EQ‐5D‐5L measure the impacts of persistent oro‐facial pain?

The EQ‐5D‐5L is a generic quality of life (QOL) measure widely used throughout the world, which has the advantage that it allows health‐state preferences to be elicited. The aim of this study was to examine whether: a) variation in the standardised reference period for EQ‐5D‐5L from ‘today’ to ‘the last month’ had a minimal clinically meaningful difference; (b) EQ‐5D‐5L had convergent validity with a multidimensional pain measure in quantifying the impacts of pain. As part of a larger study into the effectiveness and efficiency of care pathways for persistent orofacial pain (POFP) ( http://research.ncl.ac.uk/deepstudy ), participants with POFP (n = 100) completed two versions of the EQ‐5D‐5L at the same time with different reference periods (‘today’ vs. ‘last month’). Participants also completed the first section of the West Haven–Yale Multidimensional Pain Inventory (v3) to assess convergent validity. Two‐tailed nonparametric inferential statistics, intra‐class correlation coefficients (ICC), and within‐subject change scores were used to compare the two EQ‐5D‐5L versions. Convergent validity was assessed using Spearman's rho correlation coefficients. Health‐state valuations were significantly different (P < 0·01), and there was good similarity between the two versions' ICC 0·86 (95% CI 0·79–0·91). The within‐subject mean change was 0·03 (95% CI 0·01–0·06). For convergent validity, all relationships were significant (P < 0·05) and in the expected directions. EQ‐5D‐5L demonstrates sufficient convergent validity to be used with POFP, and a change in the standard reference period may be unnecessary if a multidimensional pain measure is also used.     

A 3D‐Printed Guide to Assist in Sinus Slot Preparation for the Optimization of Zygomatic Implant Axis Trajectory

Zygomatic implants have become a predictable treatment modality for the rehabilitation of the severely atrophic maxilla. Due to differing anatomic variations, proximity to vital anatomic structures and limited intraoperative visibility, the placement of zygomatic implants can be a difficult task; compromised implant positioning may ultimately lead to postoperative surgical and prosthetic complications. The purpose of this report is to demonstrate a technique that allows for the transfer of the sinus slot position. Ultimately, this optimizes zygomatic implant axis trajectory from preoperative prosthetic planning by using cone beam computed tomography (CBCT) and 3‐dimensional (3D) planning software to fabricate a stereolithographic 3D‐printed surgical guide.     

In-office 3D printed guide for rhinoplasty

Rhinoplasty is one of the most technically challenging aspects of facial cosmetic surgery. Various versions of predictive computer software have been developed to aid the surgeon in obtaining predictable results. In the rapidly progressing era of three-dimensional (3D) printing, we present an intraoperative technique that has enabled us to reliably monitor planned surgical changes to the nasal form.