Links between oral health-related quality of life in US adults and type 2 diabetes: structural equation modeling analysis.

OBJECTIVES: To analyze the effects of type 2 diabetes mellitus (T2DM), need for dental care, personal health practices and use of services on oral health-related quality of life (OHRQoL) in US adults. BASIC RESEARCH DESIGN: The sample included 2,945 participants (aged ≥ 20) selected from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 stratified probability sample that represented 124,525,899 individuals in the weighted sample. Two-stage structural equation modelling (SEM) assessed interrelationships between T2DM regressions on factors associated with OHRQoL in a simplified three-factor Andersen Behavioral Model (ABM). RESULTS: SEM supported the hypotheses that T2DM directly predicted need (perceived need, evaluated need, general health condition) with a significant path coefficient of 0.49 (ß=0.49, p⟨0.05). Need had direct (77%) and indirect (23%) effects on OHRQoL (ßdirect=0.30, ßindirect=0.09, p⟨ 0.001). Need predicted personal health practices including use of services (reason for dental visit, frequency of dental visits, smoking status) (ß=0.46, p⟨0.001). Need, in turn, predicted OHRQoL (ß=0.19, p⟨0.001). In the model, 23.8%, 59.7%, and 18.1% of the variance was explained by need, personal health practices including use of services, and OHRQoL, respectively. CONCLUSIONS: The results confirmed T2DM predicted need, which in sequence had direct and indirect effects on OHRQoL.

Mechanical behavior of facial prosthetic elastomers after outdoor weathering.

OBJECTIVES: The degradation of maxillofacial prosthetic elastomers that occurs during physical weathering is usually responsible for the replacement of prostheses. In this study the mechanical behavior of 4 non-pigmented facial prosthetic elastomers, exposed to outdoor weathering for 1 year, was investigated. The hypothesis investigated was that irradiation time did not affect the properties measured. METHODS: The samples were exposed to solar radiation for 1 year in Thessaloniki (Greece). Three different types of polydimethyl siloxane (PDMS) and chlorinated polyethylene (CPE) samples were tested in this study. Mechanical tests (compressive-tensile) were performed using a universal type testing machine. Hardness tests were evaluated using a durometer tester. Simple mathematical models were developed to correlate the measured properties with irradiation time. The stress-strain data of compression and tensile tests were modeled using parameters such as maximum stress (sigma(max)), maximum strain (epsilon(max)), elasticity parameter (E), and non-linearity parameter (p), while the mathematical model used for hardness data involves initial hardness of materials (H(0)). RESULTS: Two of the silicone prosthetics (Elastomer 42, TechSil 25) seem to become harder and more brittle contrary to the other silicone (M 511) and chlorinated polyethylene (CPE) samples that become softer and more ductile. Duration of exposure increases these phenomena. CONCLUSION: The effect of irradiation time on the mechanical behavior was introduced through its effect on the models' parameters. The hypothesis was rejected since changes were observed in the model parameters.

Array geometry for assessment of mandibular implant position using tuned aperture computed tomography (TACT).

OBJECTIVE: To evaluate observer faciolingual depth and vertical depth reading errors when using various X-ray beam array geometries to make basis images for tomosynthetic reconstruction using tuned aperture computed tomography (TACT). MATERIALS AND METHODS: Tissue-equivalent models were constructed to replicate the position of dental implants in relation to simulated mandibular canals. X-ray beam geometries used to acquire the basis images for TACT(TM) integration included horizontal linear, vertical linear, and symmetric and asymmetric conical arrays. Twenty-one dentists trained in the use of TACT acted independently as observers. Tasks included: (1) determination of the relative position of the implant in relation to the simulated canal; and (2) measurement of the vertical depth and faciolingual (lateral) depth dimensions between these two structures. As the study did not involve repeated measures (only one measure was obtained from each observer on each of the two dependent variables), data for faciolingual depth and vertical depth reading errors were analysed using a one-way analysis of variance (ANOVA) with Tukey's honestly significant different (HSD) procedure. RESULTS: Errors in determining the relative position of the implant to the simulated canal were most frequent when the linear horizontal projection geometry was employed for producing basis images (57% error for model #2 where the implant was lingually placed). The mean measurement errors for TACT images constructed using the various different projection arrays depended both on the structural relationship of anatomic features and the employed beam array geometry. CONCLUSION: Conical beam arrays are preferred over linear beam arrays for constructing basis images used with TACT for the purpose of correlating the position of a mandibular dental implant in relation to the mandibular canal. They more consistently allowed the observers to establish a measurement of the faciolingual relationship of the implant to the canal. For vertical depth measurement of the relationship of a mandibular dental implant to the mandibular canal, TACT does not appear to have any advantage over individual simple transmission radiographic images.

Effect of adhesive retention of maxillofacial prostheses. Part 2: Time and reapplication effects.

STATEMENT OF PROBLEM: The success of most non-implant-retained extraoral prostheses depends on retention derived from skin adhesives. Part 1 of this study found that Skin-Prep Protective Dressing improved the retentive properties of adhesives and that Secure(2) Medical Adhesive was stronger than Epithane-3. Part 2 investigates the application of a second layer of adhesive to the prosthesis, which was earlier noted to improve retention at later time periods. PURPOSE: This study measured the force needed to remove silicone elastomer strips with Secure(2) Medical Adhesive from the skin of human subjects. Testing was performed before and after the removal of the strips and reapplication of the adhesive. MATERIAL AND METHODS: Secure(2) Medical Adhesive was painted on silicone rubber strips and placed in a nonsequential random order of the 3 variables to 3 sites on the ventral forearms of 21 human subjects and tested over an 8-hour period. The bond strength was measured at 0, 4, and 8 hours. After a reapplication of adhesive over the existing adhesive, additional bond strength measurements were made at 4 and 8 hours. Testing was at 10 cm/min in an Instron. All subjects had Skin-Prep coating applied before adhesive application. RESULTS: Bond strengths for both single applications and reapplications of the adhesive were greater at 0 hours and became significantly weaker after the 4- and 8-hour periods. The second application of the adhesive produced the strongest bonds when measured at 4 hours (110 N/m). Bonding was significantly higher at 8 hours if a second application of adhesive was applied at 0 or 4 hours. CONCLUSION: The results of this study indicate that the bond strength of silicone elastomer to skin decreased over an 8-hour interval. After removal of the silicone rubber strip and reapplication of Secure(2) Medical Adhesive over the existing adhesive, bond strengths increased.

Special considerations for treating dental patients exhibiting the "post-polio syndrome".

A condition called "Post-polio Syndrome" (PPS) is a special type of neuromuscular disturbance that affects some elderly patients who had polio myelitis either as children or as young adults. It has been reported that approximately 1,600,000 polio survivors are alive today. Most will seek dental care, and up to half of the survivors will present with some form of PPS. This paper describes polio, its characteristics, and the long-term consideration of PPS, and discusses the special clinical implications related to this condition. Special emphasis is placed on physical impairments, breathing problems, and difficulty swallowing. Also included are sections discussing such topics as patient scheduling, office design and housekeeping, patient management, oral hygiene, diagnostic procedures, drug and pain management, and general health considerations.

Using focus groups to develop a heart disease prevention program for ethnically diverse, low-income women.

Although low-income women have higher rates of cardiovascular disease (CVD) than higher-income women, health promotion and disease prevention are often low priorities due to financial, family, and health care constraints. In addition, most low-income women live in environments that tend to support and even promote high risk CVD behaviors. Low-income African-American, Hispanic, and White women constitute one of the largest groups at high risk for CVD but few heart disease prevention programs have effectively reached them. The purpose of this project was to use feedback from focus groups to generate ideas about how to best structure and implement future CVD intervention programs tailored to low-income populations. Seven focus groups were conducted with 51 low-income African-American, Hispanic, and White women from two urban and two agricultural communities in California. The women in the study shared many common experiences and barriers to healthy lifestyles, despite their ethnic diversity. Results of the focus groups showed that women preferred heart disease prevention programs that would address multiple CVD risk factors, emphasize staying healthy for themselves, teach specific skills about how to adopt heart-healthy behaviors, and offer them choices in effecting behavioral change. For health information, they preferred visual formats to written formats. They also expressed a desire to develop knowledge to help them separate health "myths" from health "facts" in order to reduce their misconceptions about CVD. Finally, they stressed that health care policies and programs need to address social and financial barriers that impede the adoption of heart-healthy behaviors.

Effect of adhesive retention on maxillofacial prostheses. Part I: skin dressings and solvent removers.

STATEMENT OF PROBLEM: The success of most maxillofacial prostheses depends on retention by medical adhesives. Products such as Smith-Nephew's Skin-Prep (SP) are available that can be used on the skin that could improve prosthesis adhesion protective dressing. The removal of adhesive from the skin is also problematic, so solvents, such as Uni-Solve adhesive remover (US), are often used. PURPOSE: This study measured the removal force of silicone elastomer strips with 2 adhesives from the skin of human subjects during the day, as affected by the use of SP and US, and determined the site of adhesive failure. MATERIAL AND METHODS: Silicone rubber strips were applied in a predetermined random order to the ventral arm surfaces of 20 human subjects. US was applied to half the sites 1 day before testing. SP was also applied to half the sites just before Epithane-3 (E3) or Secure(2) Medical Adhesive (SMA) were used to adhere the strips. They were peeled from the skin 6 hours later in an Instron at a rate of 10 cm/min. RESULTS: A 3-way within-group MANOVA revealed significant differences without interactions between adhesives (SMA=96.3 N.m, E3=24.1 N.m; P<.0005) and between use or nonuse of SP (SP=65.8 N.m, no SP=54.6 N.m; P<.0005). The use of US was not significant (no US=61.8 N.m, with US=58.6 N.m; P=.197). SMA adhered to the prostheses, whereas E3 adhered to the skin, leaving a residue (Fisher exact test; P<.0003). CONCLUSION: The combination of SMA and SP showed the highest adhesive bond strength. Overall, SMA was 3 to 5 times more retentive than E3. SP improved adhesion of both SMA (15%) and E3 (27%). SMA was still far more retentive. US had no effect on retention. SMA remained on the prostheses, whereas E3 left a difficult-to-remove residue on the skin.

Effect of root canal sealers and irrigation agents on retention of preformed posts luted with a resin cement.

This study examined the effect of three sealers and four irrigants on retention of Dentatus preformed posts luted with Panavia 21 resin cement. Gutta-percha with one of the following sealers--EWT, AH26, Nogenol, or no sealer (control)--was used to fill the root canals of 160 autoclaved incisor and premolar tooth roots. After 72 hr 8 mm post spaces were created with Dentatus Probos Pathfinders and Dentatus reamers. After irrigating the post spaces with saline, 5.25% NaOCl, 50% citric acid followed by NaOCl, or 40% H3PO4, followed by NaOCl, Panavia 21 TC cement was introduced into the canal on the Dentatus #4 stainless steel post's threads. An up-and-down and counterclockwise motion and then a forward twist seated the posts without engaging dentin. Mesiodistal and faciolingual radiographs visualized the chambers. After 72 hr posts were removed axially with an Instron at 5 mm/min. Surprisingly, using Nogenol sealer reduced post retention whereas EWT and AH26 increased retention compared with no sealer. Post retention improved after acid etchants, especially for AH26.

Simplified methods for fabricating tissue-supported implant-retained overdentures with retention from a resilient liner.

Resilient denture liner materials can be useful for tissue-supported implant-retained overdentures. They allow physiologic movement of the denture toward the tissues. This article presents a technique that offers several advantages over other methods of fabricating the overdenture with a resilient liner, and of transferring the superstructure: the acrylic resin base and the heat-cured resilient liner material are cured simultaneously; superstructure blockout is performed in the laboratory instead of in the mouth, where blockout is difficult; and direct transfer of the superstructure bar is more accurate and eliminates possible fracture of the duplicated superstructure if formed in die stone.

Overdenture retention of four resilient liners over an implant bar.

STATEMENT OF PROBLEM: Resilient denture liners offer an alternative method of designing implant-retained overdentures. Space is provided in the overdenture to envelop the implant bar with a resilient liner to be applied chairside or processed in the laboratory. The degree of retention may vary and these materials change over time. PURPOSE: This study evaluated the retention on an implant/bar prosthesis with overdentures lined with 4 resilient denture lining materials, after cyclic insertion and removal over a simulated 1.5-year period. MATERIAL AND METHODS: Four implants were placed in a mandibular edentulous cast and a gold bar superstructure was made. Overdentures were processed in Lucitone-199 and Tokuyama, Luci-Sof, Molloplast-B, and PermaSoft (with and without sealer) lining materials, cured according to manufacturers' instructions. Each of 5 overdentures contained each liner and were cycled 2740 times (simulating 1.5 years of service at 5 insertions daily) in 37 degrees C water in an Instron at 20 cm/min. Insertion and retention force were measured. RESULTS: The 3 silicone rubber liners were 3 to 5 times more retentive than the plasticized acrylic liner initially. After cycling, Tokuyama soft liner (autopolymerized silicone) gained 14% retention, Luci-Sof (heat-cured silicone) gained 8%, Molloplast-B (heat-cured silicone) lost 12%, whereas PermaSoft (autopolymerized plasticized acrylic) with sealer lost 43%, and without sealer lost 60%. PermaSoft lining material also chafed and crumbled after cycling and was significantly less retentive in most statistical comparisons. CONCLUSIONS: All the silicone-based resilient liners retained the overdentures well. The plasticized acrylic was less retentive initially, and lost significant retention after 2740 cycles, compared with silicone-based resilient liners.

Vertical-horizontal illusion: one eye is better than two.

The vertical-horizontal illusion is the tendency for observers to overestimate the length of a vertical line relative to a horizontal line that has the same length. One explanation of this illusion is that the visual field is elongated in the horizontal direction, and that the vertical-horizontal illusion is a kind of framing effect (Künnapas, 1957a, 1957b, 1957c). Since the monocular visual field is less asymmetric than the combined visual field, this theory predicts that the illusion should be reduced with monocular presentation. This prediction was tested in five experiments, in which the vertical-horizontal illusion was examined in a variety of situations--including observers seated upright versus reclined 90 degrees, monocular presentation with the dominant versus the nondominant eye, viewing in the dark versus in the light, and viewing with asymmetrical frames of reference. The illusion was reliably reduced with monocular presentation under conditions that affected the asymmetry of the phenomenal visual field.

Evaluation of radiopaque denture liner.

Radiopacity is needed in polymeric biomaterials to facilitate noninvasive detection. Permanent denture liner material with barium sulfate filler is nearly as radiopaque as aluminum and would be useful in radiographic identification. If 1 mm to 3 mm thicknesses are used, it should be easily observable radiographically.

Noble alloys in dentistry.

Noble metals used for dental castings continue to consist of alloys of gold, palladium, and silver (not a noble metal), with smaller amounts of iridium, ruthenium, and platinum. The majority are used as a backing for ceramic baking, with the rest used as inlays, onlays, and unveneered crowns. Base metal alloys, principally made of nickel, chromium, and beryllium have gained widespread usage, especially in the United States, due to their lower cost and higher mechanical properties. The current literature, for the most part, cites the use of noble alloys as controls for trials of alternative materials. Direct gold (gold foil) still retains a following and a number of new patents were founded.

Squamous cell carcinoma of the tongue in a young woman. Report of a case with etiologic considerations.

An uncommon case of squamous cell carcinoma of the tongue in a young adult is presented. The lesion was physically related to a metallurgically flawed gold crown that was in place for 15 years. Detailed recording of findings and reporting of nontypical cases of oral cancer is suggested with a view to identification of etiologic factors.