Evaluation of the clinical performance of different occlusal device materials.

STATEMENT OF PROBLEM: Computer aided technologies have been used to fabricate occlusal devices. However, the clinical behavior of the newly developed materials developed for occlusal devices is unknown. PURPOSE: The purpose of this prospective, double-blind study was to assess the clinical efficacy of recently introduced computer-aided design and computer-aided manufacturing (CAD-CAM) materials for the fabrication of occlusal devices. MATERIAL AND METHODS: A total of 24 participants were divided randomly into 2 study groups; polyetheretherketone (PEEK) and polymethyl methacrylate (PMMA), and a control group (CG). Conventional impressions and gypsum casts were obtained from all participants. In the study groups, the casts were digitalized with an extraoral digital scanner, designed with a software program (Bite Occlusal Device Module; exocad GmbH) and milled from PEEK and PMMA blocks. Clear resin sheets were used for occlusal device fabrication in the CG. The baseline measurements were made during the initial appointments. After 6 months, the participants returned for follow-up evaluations. Clinical performance based on surface roughness, wear of the antagonist teeth, occlusal device fit and therapeutic effect, as well as participant satisfaction were compared using the 1-way ANOVA test between the main groups (α=.05). The post hoc and Kruskal Wallis-H tests were used to compare the nonparametric group. RESULTS: The therapeutic effects of the occlusal devices did not differ. All participants showed improvement in palpation and mandibular movement scores, but no statistically significant differences were found among the groups (P>.05). PEEK and PMMA had statistically less surface wear than CG (P<.001) and led to less antagonist tooth wear. No significant participant satisfaction difference was seen among the groups (P>.05). The control group had the best fit (P<.001). CONCLUSIONS: Recent CAD-CAM materials exhibit clinically acceptable outcomes, and their performance is comparable with that of traditional materials. CAD-CAM materials appear suitable in terms of accuracy, surface wear, and therapeutic efficacy.

Use of ultrasonography in the diagnosis of temporomandibular disorders: a prospective clinical study.

OBJECTIVES: Panoramic radiographs, computed tomography, and magnetic resonance imaging (MRI) are traditionally used for imaging temporomandibular joint (TMJ) and its pathologies. Besides these radiographic techniques, the recent use of ultrasonography (US) in diagnosing joint diseases has been introduced. However, there is no prospective clinical study examining the application of US in imaging of Temporomandibular Disorders (TMD) patients. Therefore, this study aimed to determine the features of the joint and surrounding structures in the US in TMD patients. METHODS: 320 patients fulfilled the inclusion criteria, and 100 of these individuals accepted to participate in the study. This study evaluated 200 TMJ; including the right TMJ and left TMJ of 100 patients. The study was designed as a clinical single-blind observational device trial. RESULTS: It has been seen that women are 3.54 times more likely to have muscle pain than men. It has been determined that the probability of joint pain increased as the joint space with the mouth closed increased. It has been seen that women are 3.61 times more likely to experience headaches than men. CONCLUSIONS: The US, which is becoming increasingly common in dentistry, can be used as an aid in TMD diagnoses. US will not be sufficient when it is desired to evaluate the TMJ joint area more precisely and clearly in patients who will be planned for advanced surgical intervention. Therefore, it may be necessary to refer for MRI. The values of our findings will be a reference in TMD diagnoses. GOV ID: NCT04452110.

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.

Comparing the precision of reproducibility of computer-aided occlusal design to conventional methods.

PURPOSE: Reconstruction of patients' dental occlusion should be performed to fulfill esthetic and functional demands. These applied restorations should be in harmony with the existing occlusion and should not have any negative effects on intraoral dynamics. The aim of this clinical study is to compare the accuracy of the occlusal design shaped by conventional Wax Up methods and computer-aided design (CAD) regarding their similarity to the natural tooth morphology. METHODS: Impressions of 10 caries-free jaws were taken, and the resulting gypsum casts were scanned with a laboratory scanner. Preparations for all-ceramic full crowns were performed on second premolars and second molars. Occlusal design of 40, 3-member fixed partial dentures (FPD) were obtained with two different methods 10 FPD was designed with conventional wax up technique (Wax Up), 30 design was performed with CAD Dental wings open system (DWOS) software using three different anatomy libraries (Dental Wings (DW), Merz, Vita). The data of the bridges in the STereo-Lithography Interface Format (STL) was compared with the pre-cut data, which was regarded as a reference in terms of accuracy in the Atos so high end 3D digitizer. RESULTS: According to the results of Kruskal-Wallis test, there was no statistical difference between the Wax Up, Vita, Merz and Dental Wings groups (p>0.05) when compared to the natural teeth. The main difference between all four groups and natural surface was 550±130µm. CONCLUSIONS: Occlusal design produced by conventional techniques and CAM DWOS system compared to natural tooth morphology showed no statistically significant difference.

Effect of vulcanization temperature and dental stone colour on colour degradation of maxillofacial silicone elastomers.

BACKGROUND: Colour degradation is a major problem in maxillofacial silicone elastomers. Recent studies have focused on colour stability and the mechanical properties of the silicone elastomers. A colour match is also essential for the acceptance of the prosthesis by the patient. The aim of this study is to assess the colour degradation of the silicone elastomer after being moulded in different colours of dental stones at two different vulcanization temperatures. METHODS: Five different colours of dental stones were used to fabricate a total of 120 silicone blocks using a Cosmesil M511 maxillofacial silicone elastomer. Vulcanization was completed at two different temperatures (25 and 100° Celsius). Colour measurements were obtained with a Conica Minolta spectrophotometer. The CIEDE2000 formula was used to calculate the colour differences (∆E00). Two-way ANOVA, one-way ANOVA with Bonferroni corrected post-hoc p values and independent samples t-test were used for the statistical analyses. RESULTS: High temperature vulcanization causes lightening of the maxillofacial silicone elastomers without regard to the dental stone colour (p = 0.001). Specimens moulded in green stone lightened least at room temperature (p = 0.999). Compared to the control group, at high temperature, all specimens moulded in coloured dental stones darkened significantly (p < 0.001 for white, blue and yellow; p = 0.006 for green; p = 0.045 for reddish-brown). In the high temperature group, the shift to a green chroma was significant in the white, yellow and green dental stones groups (p = 0.001, p = 0.002, p < 0.001, respectively). The mean b* of the high temperature control group was higher than that of the room temperature control group (p < 0.001). The only ∆E00 score lower than the perceptibility threshold for dental materials (∆E00 = 1.30) was between the room temperature control group and the room temperature green dental stone group (∆E00 = 0.96). CONCLUSIONS: Green and blue dental stones cause less colour degradation in silicone elastomers. Reddish-brown dental stones cause the most colour degradation in silicone elastomers. At 100 °C, the colour of the silicone elastomer lightens and yellows even if the elastomer is vulcanized in a stainless steel mould. White, yellow and reddish-brown dental stones make the silicone elastomer appear more yellow even if the elastomer is vulcanized at room temperature.

Frequency of temporomandibular disorder signs and symptoms among call center employees.

OBJECTIVE: The current study aimed to investigate the frequency of signs and symptoms of temporomandibular disorders (TMD) among call center employees. METHODS: Workers from four call centers (CC) were invited to participate in this study. The examination was based on the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). The tenderness of the masticator muscles was assessed on both sides by bilateral palpation. The mobility of the mandible was measured with a plastic millimeter ruler on opening, lateral excursions, and protrusion. RESULTS: In total, 124 call center employees with a mean age of 28.61 ± 4.71 (between 22 and 47 years of age) were enrolled in this study. There was no statistically significant relation between the numbers of calls answered in a day and teeth clenching, teeth grinding, earache, tinnitus, or pain on yawning/chewing. Only protrusive movement pain and joint noise were significantly higher among employees who answered more than 140 calls/day (p < 0.01). An evaluation of the TMD signs and symptoms in relation to job stress level revealed that job stress level significantly affected the incidence of headaches among call center employees (p < 0.01). CONCLUSION: The present study demonstrated no statistically significant relation between TMD signs and symptoms and call center employees except protrusive movement pain and joint noise. This relation was seen only in the employees who answered more than 140 calls per day. Headache, teeth clenching, and TMJ noise were the signs and symptoms encountered most often in this study. Multicentered studies in different geographic locations should be conducted to eliminate the limitation of this study.

Soft Tissue Response and Survival of Extraoral Implants: A Long-Term Follow-up.

Maxillofacial defects may be reconstructed by plastic surgery or treated by prosthetic mean rehabilitation. In case of large defects, prosthetic rehabilitation rather than surgical reconstruction is preferred due to the insufficient esthetic results of surgical interventions. However, retention of the craniofacial prosthesis is a great problem despite the satisfactory esthetic results. With the presentation of extraoral implants, the retention of maxillofacial prostheses was improved, and osseointegrated craniofacial implants have become indispensable for retention and stability. However, there are conflicting results regarding the success rates of osseointegrated implants used at the craniofacial region. A total of 24 patients with 64 implants (30 in auricular region of 13 patients, 24 in nasal region of 8 patients, and 10 in orbital region of 3 patients) ranging in age from 16 to 83 years (mean age = 45.45 years) were evaluated. One patient among 13 patients (1/13) has lost his implants in the auricular area, 1 patient among 8 patients (1/8) lost his implants, and 1 patient among 3 patients (1/3) has lost all of her implants. Peri-implant soft tissue response was evaluated for a 60-month period and a total of 654 visits/sites recorded. Grade 0 (no irritation) was present in 72.8% (476/654) of the visits/sites. Grade 1 (slight redness) was observed for 18.8% (123/654). Grade 2 (red and slightly moist tissue) was scored in 6.9% (45/654). Grade 3 (red and slightly moist tissue with granulation) was noted in 1.5% (10/654) and grade 4 (infection) could not be found. Ossseointegrated implants provide reasonable support and show successful results when used with maxillofacial prostheses.

Early results of low-level laser application for masticatory muscle pain: a double-blind randomized clinical study.

BACKGROUND: To evaluate the effect of Low Level Laser (LLL) application at the points of greatest pain in patients with chronic masticatory muscle pain. METHODS: A total number of 30 (21 women, 9 men, with a mean age of 39.2) were selected after the diagnosis of MPDS according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). The patients were randomly divided into three groups; laser group I (n = 10); patients received the LLL at the point of greatest pain, laser group II (n = 10); patients received LLL at pre-established points in the effected muscles and placebo group (n = 10). LLL and placebo were applied three times per week, for a total of 12 sessions. Mandibular mobility was examined, masticator muscles tenderness were assessed and PPT values were obtained. Subjective pain levels were evaluated using VAS. The measurements performed before the treatment and after the completion of the therapy. Descriptive statistics (mean, standard deviation, and frequency) Student's t-test, Mann-Whitney U-test and paired-sample t-tests were used for analysis. RESULTS: In both laser groups, there was a statically significant reduction in PPT values of the muscles, number of muscles without any pain on palpation increased significantly, mandibular movements' ranges were improved. Laser group I demonstrated statistically better results than the Laser group II in all of the measured values. Plasebo group did not show any statistically difference in any of the measured values. CONCLUSIONS: LLLT can be accepted as an alternative treatment modality in the management of masticatory muscle pain and direct irradiation seems to effect better. TRIAL REGISTRATION: Current Controlled Trials ISRCTN31085 , Date of registration 28/08/20145.

The role of components of the extracellular matrix and inflammation on oral squamous cell carcinoma metastasis.

OBJECTIVES: Oral squamous cell carcinoma (OSCC) accounts for about 90% of malignant oral lesions, and is identified as the most frequently occurring malignant tumour of oral structures. We aimed to investigate the genes and pathways related with metastasis on Turkish OSCC patients. MATERIALS AND METHODS: We performed whole genome expression profiling array on an Illumina platform. A total of 24 samples with 12 OSCC and 12-paired controls that had no tumour were included in the study. Hierarchic clustering and heat map were used for data visualisation and p-values assessed to identify differentially expressed genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Ingenuity Pathway Systems (IPA) analysis were performed to consider biologic meaning of differential expression of the genes between tumour and control groups. RESULTS: We identified 790 probe sets, corresponding to 648 genes that were effective in separating invasive and metastatic OSCC. Consequently, we found statistically relevant expression results on extracellular matrix members on MMPs such as MMP3, MMP10, MMP1 and MMP9; on laminin such as LAMC2, LAMA3 and LAMB3; several genes in the collagen family; and also on chemokines from the inflammation process. CONCLUSION: Statistically relevant expression changes for MMPs, laminins, collagens, and chemokines, which are components of the extracellular matrix and inflammation process, may be considered as a molecular biomarker for early prediction. Further studies are necessary to determine and understand the molecular mechanisms that underlie OSCC metastasis.

Comparative evaluation of the effects of implant position, impression material, and tray type on implant impression accuracy.

PURPOSE: To evaluate the effect of implant position, impression, and tray material on the accuracy of implant impressions of edentulous arches with multiple implants. MATERIALS AND METHODS: Four experimental groups were produced; medium-viscosity polyvinyl siloxane (PVS) was used in 3 groups and polyether was used in 1 group. In PVS groups, different tray types were used; metal stock trays, custom acrylic tray, and full-arch perforated plastic trays. In polyether group, custom acrylic trays were used. The discrepancies in 3 dimensions were measured. RESULTS: The casts obtained exhibited small deviations (7.50-9.71 µm) from the master cast. There was no statistically significant difference between the polyether and PVS groups. Similarly, different tray materials did not produce any statistically significant discrepancies within the PVS groups. There was no significant difference among the groups when the accuracy of anterior implants were compared, but within-the-group comparisons showed that except group 1 (GR1), the posterior implants demonstrated more accuracy than anterior ones. CONCLUSIONS: Polyether and PVS can safely be used for the impressions of the edentulous arches with multiple implants and different tray types produce similar accuracy results.

In vivo evaluation of occlusalcontact area and maximum bite force in patients with various types of implant-supported prostheses.

OBJECTIVE: To determine the effects of various implant retained and/or supported prostheses on number of occlusal contacts (NOC), occlusal contact area (OCA)and maximum bite force (BF). PATIENTS AND METHODS: In total, 56 patients were included in the study; five test groups and two control groups. The patients in the treatment groups received implant-supported/retained prosthesis; over-dentures retained with two individual attachments in occlusion with complete denture, with four individual attachments in occlusion with complete denture, with four individual attachments in occlusion with fixed partial dentures or natural dentition, 6-implant retained fixed bridges in occlusion with natural dentition and 8-implant retained fixed bridges in occlusion with natural dentition. The patients in control group 1 were wearing conventional complete maxillary and mandibular dentures, whereas in control group 2 they had fixed full-arch porcelain-fused to metal restorations prostheses for both arches. Dental Pre-scale was used measure the NOC, BF and OCA. RESULTS: There was no statistically significant difference between the treatment and control groups, among the groups with regards to NOC. OCA demonstrated different results among the removable and fixed reconstruction groups. With regards to BF, removable dentures supported with four implants showed higher bite force values than controls and two implant over-dentures. Also, a fixed reconstruction using eight implants showed higher BF values than a fixed reconstruction using six implants. CONCLUSION: Use of implants for removable dentures and fixed reconstructions improve occlusal contact area and bite force.

Evaluation of orofacial function in temporomandibular disorder patients after low-level laser therapy.

OBJECTIVE: To evaluate the effect of low-level laser therapy on occlusal contact area, occlusal pressure and bite force in temporomandibular disorder patients. PATIENTS AND METHOD: Twenty patients (14 women, six men, mean age 33.1 ± 3.8 years) diagnosed with myofascial pain according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) participated in the study. Twenty healthy individuals, matched in age and gender, served as a control group. Low-level laser was applied to the mastication muscles three times per week, for a total of 10 sessions. The mandibular mobility range was evaluated. The maximum bite force, occlusal contact area and occlusal pressure were measured bilaterally with a dental pre-scale before and after treatment. All variables were analyzed descriptively. Changes in the masticatory muscle tenderness, mandibular movements, maximum bite force, occlusal contact area and occlusal pressure were compared by paired-sample Student's t-tests. RESULTS: There was a significant increase in the pressure pain threshold of the examined muscles. Mandibular movements were significantly improved in all patients. There was also a significant decrease in pain by palpation after laser exposure. However, no significant change was found in the maximum bite force, occlusal contact area or occlusal pressure after the treatment and also the values after the treatment were still significantly lower than those of the healthy individuals. CONCLUSION: This particular type of LLLT is effective at relieving pain but does not provide physical improvement.

Management of myofascial pain: low-level laser therapy versus occlusal splints.

The present study was designed to compare the effects of low-level laser with occlusal splints in patients with signs and symptoms of myofascial pain (MP) dysfunction syndrome. A total of 40 (34 women and 6 men, with a mean age of 32.84 [SD, 10.70] years) were selected after the diagnosis of MP according to the Research Diagnostic Criteria for Temporomandibular Disorder. The patients were randomly divided into 2 groups: study group (n = 20) and control group (n = 20). Low-level laser was applied to patients in the study group 2 times per week, for a total of 10 sessions. Patients in the control group were instructed to wear occlusal splints 24 h/d for 3 months. The functional examination was based on Research Diagnostic Criteria for Temporomandibular Disorder and pressure pain threshold values were obtained with the aid of an algometer in both groups. Patients' self-report of pain was evaluated with visual analog scale. Comparisons were made within and between the groups before and after treatment. Vertical movements showed statistically significant improvements after the treatments in both groups (P < 0.01), but when the groups were compared with each other, there were no significant difference between the groups. In both groups, tenderness to palpation of the muscles decreased significantly. Pressure pain threshold evaluations and visual analog scale scores revealed similar results, too. This particular type of low-level laser therapy (820 nm, 3 J/cm2, 300-mW output power) is as effective as occlusal splint in pain release and mandibular movement improvement in MP.

Clinical and radiographic outcomes of implants immediately placed in fresh extraction sockets.

OBJECTIVE: The objective of this study was to examine the clinical and radiographic results of implants placed in fresh extraction sockets for 2 years of function. STUDY DESIGN: Ten patients were presented a treatment protocol involving the extraction of their remaining mandibular teeth and immediate placement of 4 implants (2 in fresh extraction sockets; test group (TG, n = 20), 2 in mature bone; control group (CG, n = 20). Descriptive statistics for the differences between baseline and follow-up values were assessed by chi-square test. RESULTS: None of the implants lost osseointegration. The MPI Score 0 was 80.3% in SG, 82.7% in CG, and MPI Score 1 was 13.4% in SG and 14.9% in CG at the end of 1 year, and remained stable after 2 years. No significant difference in MPI, MBI, KMW, and PPD were observed between the baseline examination and controls. Chances in MBL in CG were slightly higher in SG. CONCLUSION: Placement of implants in fresh extraction sockets is a reliable treatment alternative.

Applicability of zirconia dental prostheses for metal allergy patients.

The aim of this study was to investigate the applicability of zirconium dioxide (zirconia) as a substitute for metal alloys in a group of metal allergy patients. Fourteen patients (eight women, six men) who had been restored with porcelain-fused-to-metal fixed partial dentures (FPDs) and had exhibited hypersensitivity lesions to dental alloys were enrolled in this study. Patients were previously patch-tested using standard testing substances authorized by the International Contact Dermatitis Research Group. Patients received FPDs with zirconia frameworks and occurrences of oral symptoms were evaluated. No hypersensitivity lesions in the mouth or on the skin were encountered during the follow-up period of 3 years. Zirconia FPDs may be an alternative to porcelain-fused-to-metal FPDs in patients with metal allergies.

Prosthetic rehabilitation of a patient with a mandibular defect caused by a gunshot wound.

Injuries to the orofacial region may vary from localized injuries to extensive soft and hard tissue loss. In addition to physical and psychologic damages, functional and aesthetic aspects must be restored. This clinical report describes the rehabilitation of a patient with a mandibular defect caused by a gunshot wound. Rehabilitation of this patient, with the use of an overdenture prosthesis, was performed after mandibular surgical hard and soft tissue reconstruction. A maxillary total prosthesis and an implant-supported mandibular overdenture supported by 4 osseointegrated implants were fabricated. Despite limited mouth opening and anatomic deficiencies, the patient's aesthetic and functional demands were fulfilled.

Survival and Success of ITI Implants and Prostheses: Retrospective Study of Cases with 5-Year Follow-Up.

OBJECTIVES: The use of osseointegrated implants as an endoestal anchorage device to provide support for dental prostheses is a reliable and widely accepted treatment modality. The purpose of this study was to evaluate the clinical performance of non-submerged implants placed in the maxilla or in the mandible. METHODS: A total of 146 International Team for Implantology (ITI) (Straumann AG, Waldenburg, Switzerland) implants were placed in 42 patients (20 women, 22 men, mean age 42). The cases were examined retrospectively in order to evaluate the clinical efficiency of non-submerged ITI implants and to determine the success rate of implant retained/supported prosthesis after a 5-year period. All implants were assessed clinically and radiographically on a yearly basis. RESULTS: The 5-year cumulative success rates for maxillary and mandibular implants were 91.00% and 97.81%, respectively. The most common prosthetic complication was abutment accompanied by screw loosing (3.42%). Veneering material fracture was documented in only one patient. CONCLUSIONS: Within the limitations of the observation period and sample number, the present findings confirmed sufficient success and survival rates of ITI implants placed in mandible as well as implants placed in the maxilla after a 5-year period.