Investigation of Conventional vs Nonoriginal CAD/CAM Bars with Production Stage Differences: An In Vitro Precision Study Using a Novel Technique.

PURPOSE: The aim of this study was to evaluate the precision of fit of bar frameworks fabricated using three different production processes and the effect of changes in the CAD/CAM process steps on the precision of the resulting bar frameworks. MATERIALS AND METHODS: Four implants were applied to a mandibular phantom model, and three different production techniques were used to fabricate 30 bar frameworks. In the first group, the bar frameworks were fabricated with the conventional production process (the lost-wax technique; n = 10). In the second group, a CAD/CAM production process was used with digital data collected individually from the master model for the production of each of the final bar specimens (n = 10). In the third group, a CAD/CAM production process was used with the master model being scanned once, and the single resulting data value was used for the production of all final bar specimens (n = 10). The marginal gap between bar frameworks and implants was digitally calculated (ATOS So High-End 3D Digitizer for Small Objects, GOM Inspect). Newman-Keuls multiple comparison tests, a Tukey multiple comparison test, and Pearson correlation tests were applied to the data with a level of significance of P < .05. RESULTS: The mean marginal gap value of group 1 was 95.25 ± 76.15 µm, which was statistically significantly lower than the other groups (P = .0001). For group 2, the mean marginal gap value was 152.00 ± 97.19 µm, whereas for group 3, the mean marginal gap value was 156.7 ± 78.70 µm. Among group 2 and group 3, no statistically significant difference was observed at the mean marginal gap value. CONCLUSION: The marginal gap values in the CAD/CAM bar framework groups were significantly higher than the conventional bar framework group. Among the CAD/CAM groups, the mean marginal gap values were not statistically significant.

Comparisons of measures that evaluate oral and general health quality of life in patients with temporomandibular disorder and chronic pain.

Objective: To analyze the oral and general health related quality of life (HRQOL) measures, and to establish their ability to categorize chronic temporomandibular disorders (TMD).Methods: Data were collected from 104 patients through a questionnaire with detailed socio-demographic information, the Oral Health Impact Profile (OHIP-14), the Short-Form-36 (SF-36), the Revised Symptom Checklist-90-R (SCL-90-R), and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I and II. Descriptive statistics were computed.Results: Better self-rated health and having no muscle pain were the key predictors for better physical HRQOL, whereas higher levels of depression, worse self-rated health and mandibular functioning were highly associated with worse mental HRQOL. The oral HRQOL were significantly lower in TMD patients with higher pain-related disability and worse oral health rating.Discussion: The use of the OHIP-14 in chronic TMD patients may provide valuable clinical information for better assessing the pain-related disability when compared to SF-36.

Variations in concerns reported on the patient concerns inventory in patients with head and neck cancer from different health settings across the world.

BACKGROUND: The aim was to collate and contrast patient concerns from a range of different head and neck cancer follow-up clinics around the world. Also, we sought to explore the relationship, if any, between responses to the patient concerns inventory (PCI) and overall quality of life (QOL). METHODS: Nineteen units participated with intention of including 100 patients per site as close to a consecutive series as possible in order to minimize selection bias. RESULTS: There were 2136 patients with a median total number of PCI items selected of 5 (2-10). "Fear of the cancer returning" (39%) and "dry mouth" (37%) were most common. Twenty-five percent (524) reported less than good QOL. CONCLUSION: There was considerable variation between units in the number of items selected and in overall QOL, even after allowing for case-mix variables. There was a strong progressive association between the number of PCI items and QOL.

In vitro study of effects of aging and processing conditions on colour change in maxillofacial silicone elastomers.

BACKGROUND: The inherent colour change in maxillofacial silicone elastomers becomes perceptible 6-12 months after fabrication. Determining the factors that accelerate the degradation of the prosthesis can help the clinicians increase its life span. Therefore, the aim of the study was to investigate the effect of time passage, processing temperature, and molding-stone colour on the colour change of maxillofacial silicone elastomers after darkroom storage for 6000 h. METHODS: A total of ten study molds, each incorporating ten specimen gaps were fabricated using five different colors of dental stones. The gaps were filled with coloured Cosmesil M511 maxillofacial silicone elastomer. Five of the study molds, one of each stone color, were processed at room temperature (25 °C) for 24 h while the remainder were vulcanized at 100 °C for 1 h. Two stainless-steel molds were also fabricated to obtain a total of twenty control-group specimens of the same dimensions that were processed under the same conditions as the study molds. Colour measurements of the vulcanized silicone samples were performed using a Konica Minolta spectrophotometer. Initial measurements were obtained after the blocks were removed from the molds and the final measurements were recorded 6000 h after storage in the dark at 25 °C and 40% relative humidity. The CIEDE2000 colour-difference formula was used to measure the changes in the colour. One-way and two-way ANOVA, and an independent-sample t-test were used for statistical assessments. RESULTS: For every group, the colour change exceeded the perceptible thresholds. Thus, either the vulcanization temperature or the colour of the molding stone has a significant effect on the colour change over time. Those samples vulcanized in green and white molding stones at 100 °C exhibited a significantly higher ∆L*, ∆a*, and ∆b* values relative to the samples vulcanized at room temperature. CONCLUSION: The molding-stone colour and vulcanization temperature both affect the degree of colour change after storage in a dark environment. The L*, a*, and b* values for the maxillofacial silicone elastomers are influenced by the direction of the increase or decrease according to the selected colour. This effect varies as the temperature increases.

Predictors of obturator functioning and satisfaction in Turkish patients using an obturator prosthesis after maxillectomy.

OBJECTIVE: The aim of this study was to determine the sociodemographic, behavioral, and clinical factors affecting obturator function and satisfaction using the obturator functioning scale (OFS) in maxillectomy patients rehabilitated with obturator prostheses. STUDY DESIGN: The study sample consisted of 41 maxillectomy patients. The OFS was translated into Turkish and adapted for assessing obturator functioning and patient satisfaction among Turkish patients. Data were collected from patients' medical records and self-completed questionnaires, including the Turkish version of the OFS, sociodemographic and behavioral characteristics. Descriptive statistics, Mann-Whitney U test, Spearman's correlation coefficient, and backward stepwise multiple linear regression were used for data analysis. RESULTS: Internal consistency (Cronbach's alpha = 0.85) and test-retest reliability (intraclass correlation coefficient = 0.86) were acceptable for the OFS. The most frequently reported problem was "difficulty chewing." Bivariate analysis revealed significant differences in total OFS scores in terms of surgery type, defect size, and education level, except for the other clinical and sociodemographic characteristics and behavioral factors. Education level and surgery type were found to be the most important predictors of patient satisfaction and functioning of the obturator. CONCLUSIONS: The Turkish version of the OFS might be a useful tool for clinicians to identify patients who are at risk for poor functioning of the obturator, lack of satisfaction, and unmet needs.

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.

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.

A surface roughening technique for maxillofacial prostheses.

Giving a natural surface texture to the maxillofacial prostheses is one of the major goals for the maxillofacial prosthodontists. This article describes a technique for application of an antiskid epoxy resin to the surface of the definitive mold before pouring the maxillofacial silicone elastomer. This technique produces evenly distributed and same-size pores that are more similar to the natural appearance of human skin.

Validation of the Turkish version of the Liverpool Oral Rehabilitation Questionnaire version 3 (LORQv3) in prosthetically rehabilitated patients with head and neck cancer.

BACKGROUND: The Liverpool Oral Rehabilitation Questionnaire version 3 (LORQv3) is a measure assessing the impact of oral rehabilitation on patients' health-related quality of life (HRQOL).The aims of the study were to adapt culturally the LORQv3 for Turkish-speaking head and neck cancer patients who had undergone prosthetic rehabilitation and to undertake an initial investigation of its psychometric properties. METHODS: The Turkish version of the LORQv3 was translated and culturally adapted into Turkish, and tested on a sample of 46 head and neck cancer patients who had undergone prosthetic rehabilitation at a university clinic. Patients were categorized into three groups: Patients with maxillary obturator prostheses treated by surgery alone (n = 15); Patients with maxillary obturator prostheses treated by surgery plus radiotherapy, with or without chemotherapy (n = 23); and, Nasopharyngeal cancer patients without maxillary defects wearing conventional dental prostheses who had been treated by radiotherapy with or without chemotherapy (n = 8). Data were collected through clinical examinations and self-reported questionnaires, including socio-demographic characteristics, the LORQv3, and the University of Washington Quality of Life questionnaire version 4 (UW-QOLv4). The psychometric evaluation included validity (content, face, construct, and criterion) and reliability (internal consistency and test-retest). RESULTS: All sections of the LORQv3 showed satisfactory internal consistency, with Cronbach's alpha between 0.71 to 0.82. Kappa statistics showed moderate to perfect test-retest reliability for the 33 LORQv3 items. We found significant negative correlations between the LORQv3 and the UW-QOL v4 for some related items. The LORQv3 also identified differences in responses among patient groups, supporting its construct and criterion validity. CONCLUSIONS: This study provides initial evidence in support of the validity and reliability of the Turkish version of LORQv3 in prosthetically rehabilitated patients with head and neck cancer; it could be used in clinical practice in Turkey.

Identifying potential predictors of pain-related disability in Turkish patients with chronic temporomandibular disorder pain.

BACKGROUND: The aims of this study were to examine whether patients' psychosocial profiles influence the location of pain, and to identify the clinical and psychosocial predictors of high levels of pain-related disability in temporomandibular disorders (TMD) patients with chronic pain at least 6 months in duration. METHODS: The Research Diagnostic Criteria of TMD (RDC/TMD) data for Axis I and II were obtained for 104 consecutive patients seeking treatment.Data were analyzed using descriptive statistics, t-test, Mann-Whitney U-test, chi-square test, One-way ANOVA, Kruskal-Wallis test, and binary multiple logistic regression tests. Patients were classified into two groups according to Graded Chronic Pain Scale scores: Grade III and IV were scored for patients with high levels of pain-related disability, whereas Grade I and II were scored for patients with low disability. RESULTS: Muscle and joint pain were found in 64.9% and 31.8% of the patients, respectively, and 27.3% of the patients suffered from both muscle and joint pain.Psychosocial disability was found in 26% of patients. There were no statistically significant differences among the diagnostic subgroups with regards to the demographic, behavioral, psychological, and psychosocial characteristics. Patients with high levels of pain-related disability had significantly higher depression, somatization, pain intensity and jaw disability scores than those with low levels of pain-related disability.Patients with high levels of pain-related disability were more likely to have higher pain intensity, to report higher somatization symptoms and functional impairment, and were less likely to have joint pain than those with low levels of pain related disability. CONCLUSION: In conclusion, the Turkish version RDC/TMD, based on a dual axis system, may be used to screen chronic TMD patients at high-risk for pain-related disability who need comprehensive care treatment program.

Effects of different abutment connection designs on the stress distribution around five different implants: a 3-dimensional finite element analysis.

The stability of the bone-implant interface is required for the long-term favorable clinical outcome of implant-supported prosthetic rehabilitation. The implant failures that occur after the functional loading are mainly related to biomechanical factors. Micro movements and vibrations due to occlusal forces can lead to mechanical complications such as loosening of the screw and fractures of the abutment or implants. The aim of this study was to investigate the strain distributions in the connection areas of different implant-abutment connection systems under similar loading conditions. Five different implant-abutment connection designs from 5 different manufacturers were evaluated in this study. The investigation was performed with software using the finite element method. The geometrical modeling of the implant systems was done with CATIA virtual design software. The MSC NASTRAN solver and PATRAN postprocessing program were used to perform the linear static solution. According to the analysis, the implant-abutment connection system with external hexagonal connection showed the highest strain values, and the internal hexagonal implant-abutment connection system showed the lowest strain values. Conical + internal hexagonal and screw-in implant abutment connection interface is more successful than other systems in cases with increased vertical dimension, particularly in the posterior region.

Manufacturing implant supported auricular prostheses by rapid prototyping techniques.

Maxillofacial prostheses are usually fabricated on the models obtained following the impression procedures. Disadvantages of conventional impression techniques used in production of facial prosthesis are deformation of soft tissues caused by impression material and disturbance of the patient due to. Additionally production of prosthesis by conventional methods takes longer time. Recently, rapid prototyping techniques have been developed for extraoral prosthesis in order to reduce these disadvantages of conventional methods. Rapid prototyping technique has the potential to simplify the procedure and decrease the laboratory work required. It eliminates the need for measurement impression procedures and preparation of wax model to be performed by prosthodontists themselves In the near future this technology will become a standard for fabricating maxillofacial prostheses.