Patient preference for light-cured composite bite splint compared to heat-cured acrylic bite splint

Short-Term Effects of 3D-Printed Occlusal Splints and Conventional Splints on Sleep Bruxism Activity: EMG-ECG Night Recordings of a Sample of Young Adults

(1) Background: This study aims to compare the effects of 3D-printed splints and conventional manufactured splints on sleep bruxism (SB) EMG activity. (2) Methods: Twenty-six patients (19 M, 7 F, 25.8 ± 2.6 years) were randomly allocated to a study group (3D splints) and a control group (conventional manufactured splints) and followed for a period of three months with night EMG-ECG recordings. Samples of the involved materials were analyzed for nanoindentation. The outcomes of interest considered were the overall SB index, the total amount of surface masseter muscle activity (sMMA), and general and SB-related phasic and tonic contractions. A statistical evaluation was performed with a confidence interval (CI) between 2.5% and 97.5%. (3) Results: Differences between groups with OAs were observed for general tonic contraction (p = 0.0009), while differences between recording times were observed for general phasic contractions (p = 0.002) and general tonic contractions (p = 0.00001). Differences between recording times were observed for the total amount of sMMA (p = 0.01), for general phasic contractions (p = 0.0001), and for general tonic contractions (p = 0.000009) during night recordings without OAs. (4) Conclusions: Three-dimensional splints seem to have a higher impact on SB-related electromyographic activity but not on the overall sleep bruxism index. The more regular surfaces offered by 3D splints could be related to phasic contraction stabilization.

Effect of Nitrogen Gas Post-Curing and Printer Type on the Mechanical Properties of 3D-Printed Hard Occlusal Splint Material

Although three-dimensional (3D) printing is clinically convenient to fabricate occlusal splints, it is still unclear how the post-curing method and the printer type can affect 3D-printed splints. This study aimed to evaluate the effect of stroboscopic post-curing at a nitrogen gas (N2) atmosphere versus post-curing in an air atmosphere, as well as the printer type (liquid crystal display (LCD) and digital light processing (DLP)) on the mechanical properties of a 3D-printed hard-type occlusal splint material. Flexural strength, flexural modulus, Vickers hardness number (VHN), fracture toughness, degree of double bond conversion (DC), 3D microlayer structure, water sorption, and water solubility were evaluated. The post-curing method significantly affected all evaluated properties except fracture toughness and 3D microlayer structure, while the printer type significantly affected all evaluated properties except flexural strength and flexural modulus. VHN and DC were significantly higher, and the smoother surface was noticeably obtained when printed by LCD printer and post-cured at an N2 atmosphere. The current results suggested that the post-curing method and the printer type would play a role in the mechanical properties of the evaluated material and that the combination of post-curing at an N2 atmosphere and LCD printer could enhance its mechanical properties and surface smoothness.

Evaluation of the mechanical properties and degree of conversion of 3D printed splint material

OBJECTIVE

To evaluate the effect of post-curing method, printing layer thickness, and water storage on the mechanical properties and degree of conversion of a light-curing methacrylate based resin material (IMPRIMO® LC Splint), used for the fabrication of 3D printed occlusal splints and surgical guides.

METHODS

96 bar-shaped specimens were 3D printed (Asiga MAX), half of them with a layer thickness of 100 μm (Group A), and half with 50 μm (Group B). Each group was divided in three subgroups based on the post-curing method used: post-curing with light emitting diode (LED) and nitrogen gas; post-curing with only LED; and non-post-curing. Half of the specimens from each subgroup were water-stored for 30 days while the other half was dry-stored (n = 8). Flexural strength and flexural modulus were evaluated. Additional specimens were prepared and divided in the same way for surface hardness (n = 96), fracture toughness, and work of fracture (n = 96). Five specimens were selected from each subgroup for evaluating the degree of conversion (DC). Data were collected and statistically analyzed with 1-way, 2-way ANOVA, and Tukey post-hoc analysis (α = 0.05).

RESULTS

The 2-way ANOVA showed that the post-curing method and water storage significantly affected the investigated mechanical properties (P < 0.001). The 1-way ANOVA revealed a statistically significant difference among the tested groups on the investigated properties (P < 0.001). After water storage, the 100 μm subgroup post-cured with only LED showed higher flexural strength (51 ± 9) than the 50 μm and 100 μm subgroups that were post-cured with LED in addition to nitrogen gas atmosphere (38 ± 5, 30 ± 3) (p < 0.05). The 50 μm subgroup post-cured with only LED showed the highest significant flexural modulus values (1.7 ± 0.08) (p < 0.05). However, the 50 μm subgroup post-cured with LED plus nitrogen showed significantly higher surface hardness values (p < 0.05) among the investigated groups. The non-post-cured subgroups showed the lowest values, which were significantly different from the other subgroups (p < 0.05).

CONCLUSION

The post-curing method, water storage, and printing layer thickness play a role in the mechanical properties of the investigated 3D Printed occlusal splints material. The combination of heat and light within the post-curing unit can enhance the mechanical properties and degree of conversion of 3D printed occlusal splints. Flexural strength and surface hardness can increase when decreasing printing layer thickness.

Preliminary clinical evaluation of traditional and a new digital PEEK occlusal splints for the management of sleep bruxism

OBJECTIVE

To compare the manual time and preliminary clinical effects between the digital manufactured occlusal splints for sleep bruxism patients with those of traditional hard splints.

METHODS

Sixteen individuals (18 to 44 y/o) with clinically diagnosed sleep bruxism were selected based on the inclusion criteria. All patients were divided into two groups, and a random control method was applied. Digital splints (test group) were designed and milled using CAD/CAM. Hard splints (control group) were made of transparent acrylic resin in laboratory office. The manual time spent including impression obtaining, splint production and clinical occlusal adjustment was recorded. A visual analog scale was used to report the subjective evaluations. The maximum depth loss and volumetric loss of the occlusal surface of splints in posterior tooth were measured. SPSS software was used for statistical analysis (P = .05).

RESULTS

Comparing with control group, the manual time spent in test group was significantly less in all of three procedures (P < .001). The VAS scores for retention were not significantly different (P = .086), but the wearing comfort scores of test group were significantly higher (P < .001). Both maximum depth loss (P = .007) and volumetric loss in test group were significantly less than control group (P = .005).

CONCLUSION

In the current study, the digitally manufactured splints exhibit significantly improved comfort and time efficiency than traditional hard splints. Moreover, the new milling material (PEEK) has better wear resistance than acrylic resins.

Advances in materials and concepts in fixed prosthodontics: a selection of possible treatment modalities

The introduction of adhesive techniques in combination with translucent restorative materials has greatly influenced treatment concepts in fixed prosthodontics. Modern production technologies offer access to new polymer materials that provide innovative pre-treatment options for complex prosthetic rehabilitations. Additionally, computer-aided design and manufacturing (CAD/CAM) provides access to new ceramic types and thus extends the range of indications for metal-free restorative options. With these developments, important changes of treatment concepts in fixed prosthodontics have occurred which affect the professional life of dental practitioners with a focus on prosthetic dentistry. This article gives an overview of the advances in selected fields of fixed prosthodontics and provides support in material selection for different kinds of indications, from single-tooth restorations to fixed dental prostheses.

Surface roughness and wear behavior of occlusal splint materials made of contemporary and high-performance polymers

With the development of a digital technology of computer-assisted manufacturing (CAD/CAM) and new age materials, the use of new types of occlusal splint is to consider. The aim of the present study was to evaluate the surface roughness (Ra) and wear behavior of different CAD/CAM materials against enamel antagonist through a simulated chewing test. A total of 75 specimens made from ethylene vinyl acetate (EVA), polymethyl methacrylate (PMMA), polycarbonate (PC), polyetheretherketone (PEEK), and polyethyleneterephthalate (PETG) as a control were polished to evaluate the Ra before loading by optical profilometry and further analyzed by scanning electron microscopy (SEM). Specimens of each group were subjected to thermomechanical fatigue loading in a chewing simulator (60000 cycles at 49 N with 5-55 °C thermocycling). The wear volume loss and change in Ra of each specimen after the simulated chewing were analyzed. One-way ANOVA, paired samples t test, and Pearson correlation analysis were performed for statistical analyzes. The result showed that the volume loss and Ra varied among the materials tested. EVA exhibited the greatest amount of Ra and volume loss (p < 0.001), while PEEK had the lowest values for both (p < 0.001). In terms of volume loss, there was no significant difference between PC and PMMA (p > 0.05). SEM investigations revealed different wear behaviors, especially in EVA. As PEEK showed significantly more favorable results, PEEK splints should be considered as a new therapeutic option for occlusal splint.

Effect of thermocycling on the shear bond strength of different resins bonded to thermoplastic foil applied in occlusal splint therapy

PURPOSE

Temporomandibular disorders are a group of symptoms related to the impaired function of the temporomandibular joints and associated muscles. Occlusal splint therapy is a common treatment in the aforementioned syndrome. One of the methods of manufacturing occlusal splints is to place a polymer on thermoplastic foil. The aim of this study was to evaluate the shear bond strength of light- and self-cured resins bonded to thermoplastic foil dependent on artificial aging.

MATERIALS AND METHODS

Thirty cylinders composed of light-cured resin and 30 cylinders made of self-cured resin were attached to 60 rectangular thermoplastic plates. All specimens were divided into six groups. A control study was conducted for groups 1 and 2. The other preparation groups were subjected to thermocycling by setting appropriately 1000 cycles for groups 3 and 4 and 3000 cycles for groups 5 and 6 in distilled water. Bond strength was measured in a universal testing machine. The results were subjected to statistical analysis using the Mann-Whitney U test (p ≤ 0.05).

RESULTS

The statistics revealed that the values of the shear bond strength for specimens composed of self-cured resin after 1000 and 3000 thermocycles were significantly higher than on those made of light-cured resin (p = 0.003 and p = 0.002).

CONCLUSION

The shear bond strength between the self-cured resin and the thermoplastic foil was higher and more resistant to aging than the shear bond strength between the light-cured resin and the thermoplastic foil.

Patient responses to vacuum formed splints compared to heat cured acrylic splints: pilot study

OBJECTIVE

Vacuum formed and heat cured acrylic splints have been used in the diagnosis and treatment of temporomandibular disorders. The aim of this study was to evaluate patient's preference to either the vacuum formed or the heat cured acrylic splint.

MATERIAL AND METHODS

Twenty patients planned to receive splints were chosen from the dental school. Both types of occlusal splints were fabricated for each of them. Each patient used the splints alternatively on a nightly basis for 3 weeks. After 3 weeks, each patient completed a questionnaire regarding the comfort, fit, retention, occlusal contact, taste, gingival and lip irritation, smoothness and smelling. Statistical analysis was conducted by the MacNemar's Chisquare test.

RESULTS

There was no statistical difference in patient's responses to the different splint materials except for the comfort of wearing through the night.

CONCLUSION

The vacuum formed and heat cured acrylic splint may be equally worn in patient preference for treatment of temporomandibular disorders.

Method for immediate fabrication of an occlusal device

This article describes a method of in-office fabrication of an occlusal device for treatment of bruxism patients seeking a less costly alternative to laboratory-processed splints. This technique eliminates the need for mounted casts and the expense and delay associated with commercial laboratory involvement. It also minimizes patient and operator exposure to acrylic resin monomer and high temperatures associated with its polymerization reaction by use of a light-polymerized blue urethane dimethacrylate resin.

Occlusal splints for treating sleep bruxism (tooth grinding)

BACKGROUND

Sleep bruxism is an oral activity characterised by teeth grinding or clenching during sleep. Several treatments for sleep bruxism have been proposed such as pharmacological, psychological, and dental.

OBJECTIVES

To evaluate the effectiveness of occlusal splints for the treatment of sleep bruxism with alternative interventions, placebo or no treatment.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group's Trials Register (to May 2007); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1); MEDLINE (1966 to May 2007); EMBASE (1980 to May 2007); LILACS (1982 to May 2007); Biblioteca Brasileira de Odontologia (1982 to May 2007); Dissertation, Theses and Abstracts (1981 to May 2007); and handsearched abstracts of particular importance to this review. Additional reports were identified from the reference lists of retrieved reports and from article reviews about treating sleep bruxism. There were no language restrictions.

SELECTION CRITERIA

We selected randomised or quasi-randomised controlled trials (RCTs), in which splint therapy was compared concurrently to no treatment, other occlusal appliances, or any other intervention in participants with sleep bruxism.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out independently and in duplicate. Validity assessment of the included trials was carried out at the same time as data extraction. Discrepancies were discussed and a third review author consulted. The author of the primary study was contacted when necessary.

MAIN RESULTS

Thirty-two potentially relevant RCTs were identified. Twenty-four trials were excluded. Five RCTs were included. Occlusal splint was compared to: palatal splint, mandibular advancement device, transcutaneous electric nerve stimulation, and no treatment. There was just one common outcome (arousal index) which was combined in a meta-analysis. No statistically significant differences between the occlusal splint and control groups were found in the meta-analyses.

AUTHORS' CONCLUSIONS

There is not sufficient evidence to state that the occlusal splint is effective for treating sleep bruxism. Indication of its use is questionable with regard to sleep outcomes, but it may be that there is some benefit with regard to tooth wear. This systematic review suggests the need for further investigation in more controlled RCTs that pay attention to method of allocation, outcome assessment, large sample size, and sufficient duration of follow up. The study design must be parallel, in order to eliminate the bias provided by studies of cross-over type. A standardisation of the outcomes of the treatment of sleep bruxism should be established in the RCTs.

Technical and clinical assessment of the use of a new material-based splint in orthognathic surgery

Heat or auto-cured acrylic resins are materials that are commonly used in splint construction. Newly developed light-cured resins hold promise in view of the altered characteristics of the material. The aim of this study was to evaluate how far light-curing resin-based splints can be used in orthognathic surgery. Over a period of 1 year, 141 orthognathic surgeries were planned and performed using randomly chosen light-cured splints versus auto-polymerized splints. The performance of splint fabrication, the model planning and the clinical use were assessed by different measurements. The dental technician, the orthodontist and the surgeon evaluated objective parameters (model damage, fabrication time, accuracy of registration, adjustment time) as well as subjective criteria (handling). This study revealed that the use of light-curing splints significantly improved the accuracy (97.7% versus 81.2% in the case of acrylic materials). Less time was needed for the fabrication and adjustment of the splint. There was concomitantly less model damage to be observed when light-curing resins were used (9.2% versus 83.5%) and subjective measurements revealed significantly better handling of light-curing resin-based splints. Light-curing resin splints used in orthognathic surgery seem to be advantageous.

Polymerization characteristics of light- and auto-curing resins for individual splints

OBJECTIVES

The aim of this in vitro study was to assess different resins for occlusal splints regarding a number of polymerization characteristics.

METHODS

One autopolymerizing resin (Palapress) and four light-curing resins (Acrylight, Primosplint, Triad TranSheet Colorless and Pink) were tested for flexural strength, modulus of elasticity, water sorption, volumetric shrinkage, and conversion of double bonds. These resins were polymerized for 10 and 15 min in a light oven at frequencies between 320 and 400 nm or 400 and 500 nm, respectively. Data were treated statistically by ANOVA and by Scheffé test.

RESULTS

Concerning flexural strength and modulus of elasticity, Triad TranSheet Colorless showed significantly greater values than Primosplint and Palapress (p<0.05). The light curing resins Acrylight and Primosplint featured significantly higher water sorption when cured for 10 min compared to all other resins (p<0.05). Acrylight displayed significantly higher volumetric shrinkage and a higher quantity of remaining double bonds compared to all other light-curing resins (p<0.05). Primosplint, Triad TranSheet Colorless and Pink showed significantly lower shrinkage values than autopolymerizing Palapress (p<0.05). For all light curing resins, polishing of the samples resulted in a significantly lower quantity of remaining double bonds (p<0.05) compared to unpolished samples.

SIGNIFICANCE

With respect to the polymerization properties evaluated, the light-curing resins reached similar material properties to the autopolymerizing resin or even surpassed them. Light-curing resins seem to be suitable for the fabrication of occlusal splints and can been seen as an alternative to autopolymerizing polymethylmethacrylates.

Fitting acrylic occlusal splints and an experimental laminated appliance used in migraine prevention therapy

OBJECTIVE

To evaluate clinical procedures and chair time required to seat and adjust hard, heat-cured acrylic occlusal splints and an alternative laminated appliance developed to simplify construction of migraine prevention appliances.

DESIGN AND SETTING

Single-centre study in the Oral Medicine Clinic, The Royal Hospitals, Belfast, Northern Ireland.

METHOD

Questionnaires were distributed, January-May 2003, to operators fitting occlusal splints for 100 consecutive patients selected for migraine prevention therapy. Half the appliances were made in heat-polymerised acrylic with the remainder using a novel combination of ethylene vinyl acetate and light-curing urethane dimethacrylate. Information on operator experience, the nature of any fitting surface and occlusal adjustments together with an estimate of the time taken to make alterations was recorded.

KEY FINDINGS

The need for adjustment to seat appliances intraorally was significantly less for migraine prevention appliances made using an experimental laminating technique. Where modifications were necessary, there was no significant difference in the chair time required to fit either the heat-cured hard or experimental laminated migraine prevention appliance.

CONCLUSION

Provision of migraine prevention appliances may be more time efficient if the dental practitioner considers a laminated approach to construction.

A method for fabricating an occlusal splint for a patient with limited mouth opening

This article describes the fabrication of an occlusal splint for a patient with limited mouth opening due to temporomandibular disorder. A face-bow fork is used as a tray to obtain an accurate dual-arch impression and occlusal registration.