Effect of spatial arrangement and clinical service lifetime simulation on the retention of magnetic units used in implant-anchored orbital prostheses.

STATEMENT OF PROBLEM: Evidence for the optimal spatial arrangement of magnetic attachments in implant-supported orbital prostheses is lacking. PURPOSE: The purpose of this in vitro study was to assess the effect of 6 different spatial arrangements on the retentive force of magnetic attachments following the in vitro simulation of clinical service by insertion-removal test cycles and the contribution of artificial aging to the morphological alterations induced on the magnetic surfaces. MATERIAL AND METHODS: Ni-Cu-Ni plated disk-shaped neodymium (Nd) magnetic units (d=5 mm, h=1.6 mm) were secured on leveled (50×50×5 mm, n=3) and angled (40×45×40 mm, interior angle=90 degrees, n=3) pairs of test panels in 6 different spatial arrangements: triangular_leveled (TL), triangular_angled (TA), square_leveled (SL), square_angled (SA), circular_leveled (CL), and circular_angled (CA) generating corresponding test assemblies (N=6). TL and TA arrangements included 3 magnetic units (3-magnet groups) and SL, SA, CL, and CA 4 (4-magnet groups). The retentive force (N) was measured at a mean crosshead speed of 10 mm/min (n=10). Each test assembly was subjected to insertion-removal test cycles with a 9-mm amplitude, ν=0.1 Hz, and n=10 consequent retentive force measurements at a crosshead speed of 10 mm/min at 540, 1080, 1620, and 2160 test cycles. Surface roughness alterations following the 2160 test cycles were measured by calculating the Sa, Sz, Sq, Sdr, Sc, and Sv parameters with an optical interferometric profiler with 5 new magnetic units used as a control group. Data were analyzed with 1-way ANOVA and Tukey HSD post hoc tests (α=.05). RESULTS: The 4-magnet groups had statistically significantly higher retentive force than the 3-magnet ones at baseline and following the 2160 test cycles (P<.05). In the 4-magnet group, the ranking at baseline was SA.05). CONCLUSIONS: Four magnetic attachments placed on an SL spatial arrangement resulted in the highest retention force but presented with the highest force reduction following the in vitro simulation of clinical service by insertion-removal test cycles.

Effectiveness of prosthetic rehabilitation and quality of life of older edentulous head and neck cancer survivors following resection of the maxilla: a cross-sectional study.

PURPOSE: To evaluate the effectiveness of prosthetic rehabilitation, as well as the quality of life (QOL) of older edentulous maxillectomy patients. METHODS: Effectiveness of the complete denture obturator prosthesis and QOL of N = 44 older edentulous patients who had resection of the maxilla and were restored with a definitive prosthesis that was in use for a minimum of 1 year was assessed using three instruments: European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30), Head and Neck Cancer Module (QLQ-HN35), and Obturator Functioning Scale (OFS). Data analysis was performed by one-way analysis of variance (ANOVA) on ranks, Spearman rank-order correlation, and hierarchical multivariable rank regression at α = .05 level of significance. RESULTS: Participants' gender (P < .001), adjuvant treatment (P = .016), surgical approach (P = .017), size of the maxillary defect (P = .028), participants' prosthetic history (P = .047), and dental status of the mandible (P = .038) were significantly related to the self-reported effectiveness of the complete denture obturator prosthesis. Perceived functioning of the prosthesis (P = .001), participants' gender (P = .002), the American Society of Anesthesiologists (ASA) physical status (P = .027), and surgical approach (P = .039) were significant predictors of QOL. CONCLUSION: Restoration of the edentulous maxillectomy defect is challenging. An effective definitive complete denture obturator appeared to be the strongest predictor for advanced quality of life in older maxillectomy patients. The physical status of the older participants significantly affected the overall QOL, but did not influence the self-reported functioning of the complete denture obturator prosthesis.

Illuminant metameric effects on interbrand and intrabrand color differences of direct composite resins.

STATEMENT OF PROBLEM: Information on the illuminant metameric effects on the intrabrand and interbrand differences in color of direct composite resins is lacking. PURPOSE: The purpose of this in vitro study was to evaluate the effects of different illuminations on the color differences of the same or different brands of composite resins. MATERIAL AND METHODS: Sixty-four disks were prepared from 8 different direct dental composite resins of A3 shade, and, after polymerization and hydration for 48 hours, their color coordinates were measured in the Commission Internationale de I'Eclairage (CIE) L∗a∗b∗ color space with a portable colorimeter on a black and white background under D65 (daylight), F2 (cool white fluorescence), and A (incandescence) illuminations. Translucency parameters (TP) and fluorescence intensities (FI) of the brands were also measured to assist in the interpretation of brand behavior under the illuminations. The Kruskal-Wallis and Friedman nonparametric tests with post hoc multiple comparisons tests were applied to analyze the data for differences within and between brands under all illuminations (α=.05), while regression analysis was used to estimate the relationship between D65 and F2 or A illumination data. RESULTS: Statistical analysis showed significant differences among brands (P<.05) for all color coordinates under all illuminations, with a strong linear relationship between them (R2=0.72-0.97). Intrabrand differences were significantly different across brands (P<.05) and ranged from 0.06 to 3.1 across illuminations in ΔE∗ab units (0.05 to 2.4 in ΔΕ00 units). Interbrand differences were also significantly different (P<.05), with a range of 0.15 to 8.7 ΔE∗ab units or 0.14 to 5.7 ΔΕ00 units. CONCLUSIONS: Primary color coordinates of composite resins were affected by A or F2 illumination and were strongly associated with D65 values. Redder or yellower composite resins were affected more under A or F2 illumination. Intrabrand differences, although small, may contribute to clinical mismatches under A or F2 illuminations. Clinicians should be aware that certain brand pairs may present acceptable differences under D65 illumination but could become unacceptable under A or F2 illumination.

Quality of life in patients with soft palate resection: The relationship between reported functional prosthetic outcomes and the patient's psychological adjustment.

STATEMENT OF PROBLEM: Tumors of the soft palate and the adjacent tissues often create considerable soft palate defects that are challenging for the maxillofacial prosthodontist. Soft palate obturator prostheses can usually address functional and esthetic concerns; however, the effectiveness of the prosthetic rehabilitation in improving the patient's well-being and overall quality of life (QOL) has not been extensively researched. PURPOSE: The purpose of the present research was to evaluate the function of the prosthesis, to review the interrelation between sociodemographic, medical, and treatment (SMT) characteristics, QOL, and prosthesis functioning, and to analyze the role of the prosthesis in how the patient represents the illness and the psychological coping response. MATERIAL AND METHODS: Thirty-three patients who underwent resection of the soft palate and had been using a technically successful soft palate obturator prosthesis for at least 1 year were interviewed by means of 5 questionnaires: European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30), Head and Neck Cancer Module (QLQ-HN35), Obturator Functioning Scale (OFS), Illness Perceptions Questionnaire (IPQ-R), and Mental Adjustment to Cancer Scale (MAC). Data analysis was performed at α=.01. RESULTS: The QOL (r=-0.53, P=.001), personal control (r=-0.53, P=.001), negative adjustment to cancer (r=0.47, P=.005), treatment control (r=-0.55, P=.001), consequences (r=0.62, P<.001), and emotional representations (r=0.30, P=.009) were significantly related to prosthesis functioning. Better QOL was significantly related to prosthesis functioning (P=.006), age (P=.001), sex (P=.011), and type of soft palate defect (P=.009). The most important predictors of favorable soft palate obturator functioning were age (P<.001) and type of soft palate defect (P=.01). CONCLUSIONS: A patient-perceived effective soft palate obturator prosthesis was a significant predictor for advanced QOL, better adjustment to illness and illness-related disabilities, as well as the overall coping response to cancer.

Evaluation of a Realistic Cleansing Protocol for Preventing Discoloration of Denture Resins.

PURPOSE: To evaluate the efficacy of a realistic staining/cleansing protocol for long-term prevention of discoloration of denture base resins. MATERIALS AND METHODS: Sixty discs (20 × 2.5 mm) of auto- and heat-polymerizing denture acrylic resins were fabricated following manufacturer's instructions, polished on one side and stored in water (37°C) for 24 hours before they were assigned randomly into 6 groups (3 for each material, n = 10) to receive 220 cycles of three immersion protocols. Group A was immersed in the following baths: (1) filtered coffee at 45°C for 2 minutes, (2) tap water at 24°C for 20 seconds, (3) as bath 1, (4) as bath 2, (5) Corega Extradent cleansing solution at 45°C for 3 minutes, and (6) water at 24°C for 20 seconds. Group B was immersed in the four first baths of group A (without cleansing action) and group C in bath 1 for the cumulative action of 20 cycles (80 minutes in 45°C coffee) and bath 2 for 40 seconds. A noncontact optical interferometric profilometer was used for qualitative evaluation of the specimens and a contact colorimeter to estimate color change values (ΔΕ*ab) at baseline and every 20 cycles in the baths for a total of 220 cycles. Data were statistically analyzed using a 2-way-repeated measures ANOVA with Bonferoni multiple comparisons and trend analysis at α = 0.05 level of significance. RESULTS: Data indicated changes in color from 1.7 to 14.2 ΔΕ*ab units. The highest values were related to the number of cycles and group B immersion protocol. Significant differences were found among immersion protocols (p < 0.001) and immersion cycles (p < 0.001) with a significant interaction between protocols and cycles (p < 0.001) but not between denture resins (p = 0.991). CONCLUSION: The evaluated protocol A was found effective in preventing color changes in both denture resins even after a long period of action. Protocol C had a much lower staining effect on both resins than protocol B and behaved similarly to protocol A until 140 to 160 cycles. Therefore, it is probably not appropriate for use in short-term color stability experiments.

Using modified polyetheretherketone (PEEK) as an alternative material for endocrown restorations: A short-term clinical report.

A modified polyetheretherketone (PEEK) framework material veneered with indirect light-polymerized composite resin was used as an alternative material for the fabrication of an endocrown restoration for an extensively damaged molar. The elastic modulus of the polyetheretherketone framework (4 GPa) veneered with indirect composite resin could dampen the occlusal forces protecting tooth structures better than ceramic materials. This is important in the restoration of extensively damaged molars with weak roots. Long-term clinical evidence is required before recommending the application as a substitute material.

Attitudes of dentists toward denture adhesives: A questionnaire survey in Greece.

STATEMENT OF PROBLEM: The attitudes of dental professionals toward denture adhesives (DAs) require further investigation. PURPOSE: The purpose of this survey was to assess the attitudes of dentists in Greece toward DAs and the possible effects of sex, age, training, and awareness level on these attitudes. MATERIAL AND METHODS: An 18-item questionnaire in the Greek language concerning the use of DAs by dentists in the metropolitan area of Athens, Greece was distributed on line. Its URL address was emailed to 793 randomly chosen dentists in the area, 438 of whom filled out and submitted a valid questionnaire (55.2% response rate). Data for each item were statistically analyzed for their associations with sex, age, training, and awareness level by the chi-square test for independence (α=.05). RESULTS: The results showed that 61.5% of general practitioners and 49% of specialist prosthodontists recommend the use of DAs. Their continuous use was recommended most frequently (46.9%), mainly in the cream form (93.8%). Their use was recommended not only for patients wearing older dentures (60.2%) but also for patients with newly fabricated ones (61.9%) to assist their adaptation to dentures (42.2%). Associations were found between a few only items and sex (Q07, Q11a,b), age (Q13), training (Q11q,b), and awareness level (Q11a,b,d,e) (P<.05). CONCLUSIONS: This survey shows that in the metropolitan area of Athens, Greece, a significant proportion of dentists (60.3%) recommend the use of DAs and do so more often as a continuous regimen for both existing and new denture wearers. Sex, age, training, and awareness level proved to be factors affecting only a few dentists' attitudes.

Effects of sociodemographic, treatment variables, and medical characteristics on quality of life of patients with maxillectomy restored with obturator prostheses.

STATEMENT OF PROBLEM: Restoration of maxillary defects resulting from tumor ablative surgery presents a difficult challenge, with both functional and esthetic issues. Whether rehabilitation with an obturator prosthesis could significantly contribute to improved quality of life in patients with maxillary resection has been scarcely studied, with relatively small study samples. PURPOSE: The purpose of this survey study was to assess the overall functioning of the obturator prosthesis and the effect of specific sociodemographic, medical, and treatment variables on obturator functioning and quality of life in patients with maxillectomy. MATERIAL AND METHODS: Global quality of life (QOL) and satisfaction with the obturator prosthesis of 57 patients who underwent maxillectomy and prosthetic rehabilitation at the National and Kapodistrian University of Athens were assessed using 3 questionnaires: European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire C30 (QLQ-C30), the EORTC QLQ-HN35, and the obturator functioning scale. The data were analyzed using the Kruskal-Wallis 1-way ANOVA on ranks, hierarchical multiple regression analysis, and the Spearman rank order correlation (α=.05). RESULTS: Satisfactory functioning of the obturator prosthesis was the most significant predictor of improved QOL (P<.05). QOL was significantly related to additional treatments (P<.05), the size of the primary tumor (P<.05), and the size of the maxillectomy defect (P<.05). The most significant predictors of good obturator functioning were additional treatments (P<.01), age at the time of surgery (P<.05), presence of mandibular teeth (P<.05), and previous maxillary removable prosthetic experience (P<.05). Obturator functioning scale appearance and insertion subscales (r=0.47, P<.01), followed by speech (r=0.42, P<.01), were significantly related to better QOL. CONCLUSIONS: A well-functioning obturator prosthesis was the most significant determinant for improved QOL in patients with maxillary resection. Age at the time of surgery, adjuvant treatments, presence of mandibular teeth, and previous maxillary removable prosthetic experience were the most significant predictors for better obturator functioning, whereas the size of the maxillectomy defect had a significant effect on QOL but did not influence the functional outcome.

The Use of a Modified Poly-Ether-Ether-Ketone (PEEK) as an Alternative Framework Material for Removable Dental Prostheses. A Clinical Report.

This clinical report presents a modified poly-ether-ether-ketone (PEEK) as an alternative material for the fabrication of distal extension removable dental prosthesis (RDP) frameworks. This material can be used for patients allergic to metals, or who dislike the metallic taste, the weight, and the unpleasant metal display of the denture framework and retentive clasps. This modified PEEK material, known as BioHPP, is a biocompatible, nonallergic, rigid material, with flexibility comparable to bone, high polishing and low absorption properties, low plaque affinity, and good wear resistance. It has been used for years in orthopedics and medical technology. BioHPP frameworks can be constructed either via CAD/CAM manufacturing or via the conventional lost wax technique. The clinical use of a BioHPP RDP framework is presented as an alternative for the treatment of a distal extension case.

Mechanical Properties and Simulated Aging of Silicone Maxillofacial Elastomers: Advancements in the Past 45 Years.

PURPOSE: To identify and discuss the findings of publications on mechanical behavior of maxillofacial prosthetic materials published since 1969. METHODS: Original experimental articles reporting on mechanical properties of maxillofacial prosthetic materials were included. A two-stage search of the literature, electronic and hand search, identified relevant published studies up to May 2015. An extensive electronic search was conducted of databases including PubMed, Embase, Scopus, and Google Scholar. Included primary studies (n = 63) reported on tensile strength, tear strength, and hardness of maxillofacial prosthetic materials at baseline and after aging. RESULTS: The search revealed 63 papers, with more than 28 papers being published in the past 10 years, which shows an increased number of publications when compared to only 6 papers published in the 1970s. The increase is linear with significant correlation (r = 0.85). Such an increase reflects great awareness and continued developments and warrants more research in the field of maxillofacial prosthetic materials properties; however, it is difficult to directly compare results, as studies varied in maxillofacial prosthetic materials tested with various silicone elastomers being heavily investigated, standards followed in preparing test specimens, experimental testing protocols, and parameters used in setting simulated aging conditionings. CONCLUSION: It is imperative to overcome the existing variability by establishing unified national or international standards/specifications for maxillofacial prosthetic materials. Standardization organizations or bodies, the scientific community, and academia need to be coordinated to achieve this goal. In the meantime and despite all of these theoretically significant alternatives, clinical practice still faces problems with serviceability of maxillofacial prostheses.

Effects of cleansing methods on 3-D surface roughness, gloss and color of a polyamide denture base material.

OBJECTIVE: The purpose of this study was to determine the effects of two denture cleansing methods on 3-D surface roughness, gloss and color of denture base materials. MATERIALS AND METHODS: Thirty disks from nylon (Valplast) and 30 from heat-polymerized acrylic denture base material (Paladon 65) were made and 10 of each material were immersed in water (control), Val-Clean (peroxide cleanser) and Corega Extradent (peroxide cleanser) plus microwaving for a period simulating 30 days of daily cleansing. 3-D surface roughness, gloss and color parameters were measured before and after cleansing using an interferometric profilometer, a gloss meter and a colorimeter. The results were statistically analysed by regression, paired-t, Mann-Whitney and Kruskal-Wallis tests at α = 0.05 level of significance. RESULTS: The results showed significant differences at baseline in L* and b* parameters between materials (p < 0.01), with a significantly lower gloss (p < 0.05) and higher roughness (p < 0.05) for Valplast. After cleansing, Δϵ* was significantly greater in Valplast than Paladon 65 (p < 0.05). Gloss of both materials decreased significantly within the Corega Extradent plus microwave solution (p < 0.05), while roughness increased significantly only for Paladon 65 (p < 0.05). CONCLUSIONS: Valplast was found to have a significantly lower gloss and a higher roughness than Paladon 65 before cleansing. After cleansing, ΔE* increased more in Valplast than in Paladon 65, gloss of both materials decreased and roughness only of Paladon 65 increased within the Corega extradent plus microwaving method.

Effect of light aging on silicone-resin bond strength in maxillofacial prostheses.

PURPOSE: The aim of this study was to investigate the effect of accelerated light aging on bond strength of a silicone elastomer to three types of denture resin. MATERIALS AND METHODS: A total of 60 single lap joint specimens were fabricated with auto-, heat-, and photopolymerized (n = 20) resins. An addition-type silicone elastomer (Episil-E) was bonded to resins treated with the same primer (A330-G). Thirty specimens served as controls and were tested after 24 hours, and the remaining were aged under accelerated exposure to daylight for 546 hours (irradiance 765 W/m(2) ). Lap shear joint tests were performed to evaluate bond strength at 50 mm/min crosshead speed. Two-way ANOVA and Tukey's test were carried out to detect statistical significance (p < 0.05). RESULTS: ANOVA showed that the main effect of light aging was the most important factor determining the shear bond strength. The mean bond strength values ranged from 0.096 to 0.136 MPa. The highest values were recorded for auto- (0.131 MPa) and photopolymerized (0.136 MPa) resins after aging. CONCLUSIONS: Accelerated light aging for 546 hours affects the bond strength of an addition-type silicone elastomer to three different denture resins. The bond strength significantly increased after aging for photo- and autopolymerized resins. All the bonds failed adhesively.

Short-Term Assessment of the OHIP-14 Scale on Denture Wearers Using Adhesives.

PURPOSE: The purpose of this study was to assess differences of the Oral Health Implant Profile-14 (OHIP-14) scale over a month and determine association with gender, supporting tissues (KIS), and denture base (KID) among patients wearing complete dentures using denture adhesives. MATERIALS AND METHODS: Sixteen denture wearers, candidates for a new set of complete dentures, were selected. OHIP-14 scores were recorded at the beginning of the study, 6 weeks after fitting of the new set (T0 ), 15 days (T1 ), and finally 30 days (T2 ) after daily use of a denture adhesive as instructed. The KIS and KID were clinically examined and rated according to the Kapur Index. Statistical analyses were based on repeated-measures ANOVA, Mann-Whitney test, regression analysis, and Friedman test at a = 0.05. RESULTS: The OHIP-14 scale was found to have a high reliability (alpha = 0.847) and a high test-retest consistency (ICC = 0.889); however, domain 1 had the lowest item-total correlation (rho = 0.144) and item 7 a negative one (rho = -0.414). Trend analysis indicated a significant negative linear trend over time (slope = -3.156, p = 0.002), while repeated-measures ANOVA showed differences in OHIP-14 between T2 and T1 (p = 0.003) or T0 (p = 0.005) intervals. OHIP-14 groups were found to be positively associated with KIS (p = 0.010) and negatively with KID (p = 0.047) groups, but not with gender (p = 0.272). CONCLUSIONS: The study shows that OHIP-14 has a high internal reliability and consistency when applied to new denture wearers, and its score decreases if denture adhesives are used for at least 15 days. Low KIS and high KID contributes to this trend. Some OHIP-14 items are more associated than others with the total score trend over time.

Monitoring Shore A hardness of silicone facial elastomers: the effect of natural aging and silicone type after 1 year.

OBJECTIVES: The purpose of this study was to investigate the effect of natural aging after storage in the dark for 1 year and material type on Shore A hardness of 2 silicone prosthetic elastomers. MATERIALS AND METHODS: The silicone elastomers tested were low- and high-temperature vulcanizing materials, namely, Premium and Silasto 30, respectively. Ten samples, 25 × 25 × 10 mm3, from each silicone were made and stored in sealed glass containers in the dark. Shore A hardness was measured according to the American Society for Testing Materials specification D2240. Three recordings were made on each sample at baseline and then weekly for 12 months (quadruplicate per mo). Data were analyzed by general linear modeling for repeated measures and Student-Newman-Keuls test for post hoc comparisons at α = 0.05. RESULTS: General linear modeling analysis indicated a significant influence of either silicone type (F = 229.5, P = 0.0001) or natural aging (F = 105.9, P = 0.0001) or their interaction (F = 27.6, P = 0.0001) on Shore A hardness values. For Premium and Silasto 30, Shore A hardness ranged from 16.9 to 26.0 and 32.0 to 36.3, respectively. The elastomers showed a trend to increase hardness over natural aging, which was significant (Premium) or not (Silasto 30), depending on the material and time intervals. CONCLUSIONS: Premium silicone showed a significant hardness increase after 1 year of natural aging in the dark, reaching a convergent value approximately 6 months from the onset, whereas Silasto 30 hardness remained stable during this period. Both elastomers showed Shore A hardness values within clinical acceptable limits after aging.

Dynamic mechanical thermal analysis of maxillofacial prosthetic elastomers: the effect of different disinfecting aging procedures.

In this study, dynamic mechanical thermal analysis was used to evaluate the changes that occurred in maxillofacial elastomers subjected to different disinfecting regimens. A commercial polydimethyl siloxane (PDMS) and an experimental chlorinated polyethylene (CPE) were treated with different disinfection procedures for a period that simulates 1 year of clinical service: microwave exposure (D1), hypochlorite solution (D2), neutral soap (D3), and a commercial disinfecting solution (D4). A fifth group was kept in dark storage as control. Dynamic mechanical thermal analysis tests operated in a fixed frequency (1 Hz) over a range of temperatures (-130°C to 20°C for PDMS, -60°C to 120°C for CPE). Loss modulus (G″), storage modulus (G'), and loss factor (tanδ) were recorded as a function of temperature. The obtained glass transition temperature (Tg) values were subjected to statistical analysis. Dynamic mechanical thermal analysis revealed changes in Tg values for both materials, which reflect the possible changes in their chemical and physical structure, after different disinfection procedures. The PDMS and CPE samples seem to have less dense structure maybe because of chain scission reaction that probably occurred during the disinfection procedures. According to statistical analysis, Tg values presented significant changes from the control samples among the different materials and disinfecting procedures. Microwave exposure and hypochlorite solution affect CPE significantly, whereas PDMS exhibited significant changes after being treated with a commercial antimicrobial agent, concerning changes that occurred in Tg. In all cases, Tg values were decreased compared with the untreated samples, which were stiffer, presenting higher Tg and G' values.

Effect of adaptation time on the occlusal force at denture dislodgement with or without denture adhesive.

STATEMENT OF PROBLEM: The effect of denture adhesives on the occlusal forces at the dislodgement (OFD) of new complete dentures during the adaptation period has not been previously studied. PURPOSE: The purpose of this study was to investigate the OFD of dentures after their insertion and 3 months later, with or without denture adhesives. MATERIAL AND METHODS: Thirteen volunteers with edentulism were enrolled in the study. Each participant had new complete maxillary and mandibular dentures. The occlusal forces (N) at denture dislodgement were assessed with or without 2 adhesives by using an electronic gnathodynamometer in the incisal and premolar regions on the existing denture, the new denture immediately after fitting, 45 days later, and 90 days later. The statistical analysis included the Wilcoxon and Kruskal-Wallis tests, repeated measures ANOVA, and the Pearson coefficient at α=.05. RESULTS: Repeated measures ANOVA for new dentures showed that the OFD in the incisal or premolar region were significantly different between adaptation periods (P<.05) but not between adhesives. OFDs of dentures with and without adhesives correlated highly at all adaptation periods (0.912 to 0.995). CONCLUSIONS: The adaptation period does affect the OFD of new dentures, but the 2 adhesives were found to have the same effect on the OFD.

The use of an anterior deprogrammer in a removable prosthodontic case: the key to accurate and predictable centric relation records.

Centric relation (CR) is the treatment position of choice when placing removable prosthodontics. The most common method for achieving CR in cases of removable prosthodontics is the bilateral manipulation technique. However, this technique's success depends on the dentist's experience, as it can be hard to perform when patients are stressed and/or uncooperative. Using the chin point guidance technique with an anterior deprogrammer--mainly with fixed prosthodontics--is more predictable and accurate as it achieves CR through temporomandibular joint muscle relaxation. This case report illustrates how an anterior deprogrammer can be used in a combination case such as a maxillary complete denture opposing a mandibular removable partial denture.

Tooth, skin, hair and eye colour interrelationships in Greek young adults.

The purpose of this study was to investigate the possible interrelationships of teeth, skin, eye and hair colour. A portable colorimeter (Shade Eye NCC/Shofu) was used to record the colour in the CIELAB system of the upper right incisors in 150 dental school students, along with their skin colour at three different areas. Natural hair and eye colour was classified into several categories by a trained examiner (ICC 0.93-0.99). One-way ANOVA and correlation tests were used to statistically analyse the data. Skin was found to have significantly higher L*, b* but lower a* values than teeth (p < 0.05). A significant correlation (p < 0.05) of teeth to skin L* and a*colour coordinate was found, but not to b* coordinate (p > 0.05). Hair tones were not correlated to teeth L* or b*, but only to a*coordinate. Teeth and eye colour coordinates were not correlated (p > 0.05). Eye and hair tones were found to have the highest significant correlation (ρ = 0.369). In conclusion, teeth of this cohort were found to be lighter, less red and yellow than the skin. Teeth colour was not related to eye colour, but lighter teeth were found to be associated with lighter skins, and redder lateral incisors to lighter hair. Darker facial skins or yellower forehead areas were also associated with darker hair and vice versa. The clinical relevance of the study is that the investigated facial characteristics are inter-correlated weakly to moderately, and for this reason predicting the colour parameters of one facial characteristic by another would not be accurate, but helpful for a rough colour selection as associations show.

Antimicrobial efficacy of denture adhesives on some oral malodor-related microbes.

The objective of the study was to determine the antimicrobial efficacy of three denture adhesives toward Streptococcus oralis, mutans, Prevotella oralis and Fusobacterium nucleatum. Adhesives used were Corega Ultra(®), Fixodent Pro Original(®) and Biotene(®) Denture Grip. For Streptococcus oralis and Streptococcus mutans, four tubes of Trypticase Soy Broth 10 mL and 1 g denture of adhesive were used. In addition four tubes of Trypticase Soy Broth 10 mL without any denture adhesive was employed as control. For Prevotella oralis and Fusobacterium nucleatum, four tubes of thioglycolate 10 mL and 1 g denture adhesive were used for each one, while four tubes of thioglycolate 10 mL without adhesive served as control. All samples were incubated for 48 h at 37°C. After 48 h, the number of colonies was counted and the mean was extracted as cfu/mL. The results were evaluated with ANOVA on ranked data and Tukey's post hoc test at α = 0.05. Streptococcus oralis, mutans, Prevotella oralis and Fusobacterium nucleatum showed decreased number of colonies for each denture adhesive compared to the control. Under the conditions of this in vitro study, all the tested denture adhesives showed antimicrobial efficacy. However, in contrast to the hypothesis, there were differences among them. Corega Ultra(®) and Biotene(®) Denture Grip were more effective for all the tested oral malodor-related microbes than Fixodent Pro Original(®).

Color changes of autopolymerized silicone or acrylic soft denture reliners: the effect of accelerated aging.

The aim of this in vitro study was to investigate the effect of accelerated aging on the color stability of six autopolymerized silicone and acrylic soft reliners. Ten specimens for each material were fabricated. Initial color was measured with a tri-stimulus colorimeter. One set of five specimens was placed in distilled water at 37 °C under dark for 15 days, while the remaining were subjected to photoaging initially for 1 and then for 6 days. Color changes (ΔE) then calculated. Data were analysed by ANOVA, Tukey and t tests at a = 0.05. All the reliners after storage in water showed ΔE ranged from 2.8 (Mucopren Soft) to 7.9 (Vertex Soft). After accelerated aging for 1 day, ΔE ranged from 4.6 (Vertex Soft) to 12.4 (Eversoft) whereas after 6 days from 1.7 (Ufigel SC) to 11.8 (Eversoft). All the reliners showed perceptible ΔE except Ufigel SC in 6 days aging and clinically unacceptable ΔE except Sofreliner S and Vertex Soft after aging for 1 day. Eversoft showed the highest discoloration after aging.