Pre-operative training induces changes in the histomorphometry and muscle function of the pelvic floor in patients with indication of radical prostatectomy.

OBJECTIVE: To evaluate the efficacy of preoperative pelvic floor muscle training (PFMT) on histomorphometry, muscle function, urinary continence and quality of life of patients undergoing radical prostatectomy (RP). MATERIAL AND METHODS: A prospective intervention clinical study was designed in 16 patients with indication of RP who were randomized into two groups. The Control Group received routine pre-surgical education (hygienic-dietary measures). The intervention group received a training session with supervised PFMT, three times a day, for four weeks, 30 days before the PR. Muscle function of the external urethral sphincter, contraction pressure of the levator ani, urinary continence and quality of life related to health (HRQoL) were evaluated before and after the intervention. At the end of the intervention and day of the surgery, samples of residual muscle tissue were obtained from the external sphincter muscle of the urethra for histomorphometric analysis. RESULTS: After the intervention, those participants who carried out PFMT showed an increase in the cross-sectional area of the muscle fibers of the external urethral sphincter (1,313 ± 1,075 µm(2)vs. 1,056 ± 844 µm(2), P=.03) and higher pressure contraction of the levator ani (F=9.188; P=.010). After catheter removal, 62% of patients in the experimental group and 37% in the control group showed no incontinence. After removal of the catheter, 75% of the experimental group did not require any pad compared to 25% in the control group (p=NS). There were no significant differences between the two groups in any of the HRQoL domains studied. CONCLUSIONS: Pre-surgical PFMT in patients with RP indication induces changes in the histology and function of the pelvic floor muscles, without changes in urogenital function and HRQoL. These results provide new evidence regarding the benefit of PFMT in preventing RP associated complications.

Cross-compatibility of methacrylate-based resin composites and etch-and-rinse one-bottle adhesives.

OBJECTIVE: To compare dentin shear bond strength (SBS) of four combinations of light-activated one-bottle adhesives and composites to determine if cross-compatibility exists, and to determine if the use of the same manufacturer's adhesive and composite results in higher SBS than systems that combine different manufacturers' products. METHODS: One hundred sixty human third molars were used for bonding (n=10). Specimens were treated with 37% phosphoric acid and one of four etch-and-rinse adhesives. Specimens were placed in a bonding jig, which was filled with one of four composites. Adhesives PQ1 (Ultradent), Excite (Ivoclar-Vivadent), Optibond Solo Plus (Kerr), and Single Bond (3M-ESPE) and composites Vit-l-Escence (Ultradent), Four Seasons (Ivoclar-Vivadent), Premise (Kerr), and Filtek Supreme Plus (3M-ESPE) were tested. SBS was measured at 24 hours and three months with a testing machine at a speed of 1 mm/min and expressed in MPa. A three-way analysis of variance and Tukey tests were used for data analysis. RESULTS: Significant differences were evidenced among composites for each adhesive system (p<0.001) and among adhesives for each composite system (p<0.001). Optibond Solo Plus and PQ1 yielded significantly higher bond strengths than Single Bond and Excite for all composite systems (p<0.05). All combinations, with the exception of two, demonstrated a decrease in bond strength values after aging. CONCLUSIONS: Cross-compatibility was demonstrated, indicating that etch-and-rinse one-bottle adhesive systems can be safely used with composites from different manufacturers without a compromise to the bond strength. Moreover, even higher mean SBS values were demonstrated for selective combinations of different manufacturers' products

Effects of a nutritional supplement on periodontal status.

Among the recommendations for the maintenance of gingival and periodontal health, few have focused on the value of nutritional supplements. The purpose of this study was to compare the effect of certain nutritional and plant-derived nutraceuticals and a placebo tablet in the reduction of gingivitis, bleeding, probing depths, and attachment levels in a 60-day two-cell, randomized, parallel clinical trial for patients with Type II periodontal disease. The vitamin therapy was introduced as an adjunct to patient homecare to determine if there was a quantifiable improvement to soft-tissue health and periodontal damage. Sixty-three patients were randomly divided into two groups of 32 and 31 subjects and given either a vitamin tablet containing seven active ingredients (experimental treatment) or a placebo tablet. The clinical parameters assessed were the gingival index (GI), bleeding index (BI), periodontal pocket depth (PD), and attachment levels (AL), and were recorded at baseline and 60 days. Patients took the assigned tablet at breakfast and at dinner after brushing their teeth twice daily. After 60 days, the data showed a clinical reduction in the GI, BI, and PD for the experimental group (P < .0001). There were no significant changes for AL with either the experimental or the placebo group. When the data were further analyzed for pocket depths of > or = 4 mm in patients receiving the experimental treatment, there were clinically significant improvements in the GI and PD from baseline to 60 days (P < .0001), but no significant differences in the BI and AL. There were no statistical differences in any of the indices when the data were compared between men and women. The results of the present study suggest that a multi-vitamin nutritional supplement might be a beneficial adjunct to the required established periodontal treatment.

Strengthening of tooth enamel by a remineralizing toothpaste after exposure to an acidic soft drink.

The effect of remineralizing and conventional toothpaste treatments on the hardness of intact and acid soft drink-etched enamel were assessed in a laboratory study. The remineralizing toothpaste (Enamelon Toothpaste) used in the study contains NaF, and simultaneously provides dissolved calcium, phosphate and fluoride ions. The conventional toothpaste contains NaF in a silica base. Sound extracted maxillary human incisors, mounted in epoxy resin with the facial incisal two-thirds exposed, were polished with 0.3 mu alumina. Groups of ten teeth were exposed to either twenty 5-minute treatments with an acid soft drink (pH 2.4), remineralizing or conventional fluoride toothpaste, or to twenty alternating cycles of a 5-minute protective treatment with either the remineralizing or conventional toothpastes, followed by 5-minute exposures to the acid soft drink, or to 20 five-minute exposures to the acid soft drink followed by 20 five-minute restorative treatments with the remineralizing or conventional toothpastes. Knoop Hardness measurements were made before and after treatment using a 500 g load and 15-second dwell time. Acid soft drink exposure produced a 15.4% drop in hardness compared with 4.9% and 1.6% hardness increases due to treatments of intact enamel with the remineralizing and conventional toothpastes, respectively. Protective treatments using the remineralizing and conventional toothpastes significantly reduced the drop in hardness due to acid soft drink exposure to 3.3% and 6.2%, respectively. Restorative treatments by the remineralizing and conventional toothpastes significantly increased the hardness of the acid soft drink-weakened enamel by 12.1% and 7.3%, respectively. Both toothpastes were effective in inhibiting damage due to acid soft drink exposure, but the remineralizing toothpaste was more effective in hardening intact and decalcified enamel than the conventional toothpaste (p < 0.05).

Efficacy of an alcohol-free chlorhexidine mouthrinse as an antimicrobial agent.

STATEMENT OF PROBLEM: Antimicrobial mouthrinses have become an important part of comprehensive dental care. However, mouthrinses that contain alcohol have been shown to be detrimental to patients undergoing radiation therapy for head and neck cancer, to some immunocompromised patients, to families with small children, and to persons sensitive to alcohol. PURPOSE: This study evaluated the effectiveness of alcohol-free, 0.12% chlorhexidine mouthrinse in reducing microbial levels when compared with commercially available 0.12% chlorhexidine (CHX) and essential oils mouthrinses. MATERIAL AND METHODS: This study consisted of both in vitro and in vivo investigations. The double-blind study included 32 subjects randomly assigned to 3 groups, equalized according to the indices tested. One group (n = 11) received essential oils rinse; the second group (n = 11) received CHX; and the last group (n = 10) received the alcohol-free CHX. Subjects were asked not to use any mechanical means of oral hygiene for 21 days. The in vitro part of the study consisted of Streptococcus mutans strip tests. RESULTS: Mean plaque scores for both CHX products decreased after 21 days, whereas the mean for the essential oils increased. Bleeding and gingival index scores for all 3 groups increased, which may be due to the initially healthy tissues of the participants. Relative microbial growth for S mutans for both the CHX products decreased to 0 after 21 days, whereas the counts for the essential oils group remained varied.

The effect of tooth preparation form on the fit of Procera copings.

PURPOSE: This study evaluated the marginal and internal adaptation of Procera copings using different tooth preparations. The variations comprised 4 finish line forms, 3 occlusal forms, 3 occlusocervical undulation forms to the proximal finish line, and 3 proximal auxiliary retention forms. MATERIALS AND METHODS: One hundred twenty preparations were made and copings were fabricated, cemented, embedded in an epoxy resin, sectioned, and measured at 14 sites. RESULTS: The feather-edge finish line had the highest mean external marginal opening (135 +/- 79 microns), compared with the chamfer finish line (64 +/- 38 microns), the 0.8-mm rounded shoulder (51 +/- 34 microns), and the 0.5-mm rounded shoulder (68 +/- 56 microns). All 3 forms of occlusal reduction produced comparable internal adaptation at the axial wall. Specimens with normal occlusal reduction had the best occlusal adaptation at the cusp tip but not to a statistically different degree from the exaggerated form. Variations in the vertical height of interproximal finish lines did not significantly affect marginal opening. However, proximal retentive features less than 2.5 mm wide and more than 0.5 mm deep cannot be accurately reproduced with the present Procera scanner tip. CONCLUSION: Feather-edge finish-line forms, deep retentive grooves, and deep occlusal morphology are not well reproduced using this system, but all other finish-line forms and design variations are accurately and clinically acceptably reproduced using this system.

Using a colorimeter to develop an intrinsic silicone shade guide for facial prostheses.

PURPOSE: To determine if using CIE L*a*b* color measurements of white facial skin could be correlated to those of silicone shade samples that visually matched the skin. Secondly, to see if a correlation in color measurements could be achieved between the silicone shade samples and duplicated silicone samples made using a shade-guide color formula. MATERIALS AND METHODS: A color booth was designed according to ASTM specifications, and painted using a Munsell Value 8 gray. A Minolta colorimeter was used to make facial skin measurements on 15 white adults. The skin color was duplicated using custom-shaded silicone samples. A 7-step wedge silicone shade guide was then fabricated, representing the commonly encountered thicknesses when fabricating facial prostheses. The silicone samples were then measured with the Minolta colorimeter. The readings were compared with the previous L*a*b* readings from the corresponding patient's skin measurements, and the relative color difference was then calculated. Silicone samples were fabricated and analyzed for three of the patients to determine if duplication of the visually matched silicone specimen was possible using the silicone color formula, and if the duplicates were visually and colorimetrically equivalent to each other. The color difference Delta E and chromaticity was calculated, and the data were analyzed using a coefficient-of-variation formula expressed by percent. A Pearson Product Moment Correlation Coefficient was performed to determine if a correlation existed between the skin and the silicone samples at the p < or = .05 level. RESULTS: The highest correlation was found in the b* dimension for silicone thicknesses of 1 to 4 mm. For silicone thicknesses of 6 to 10 mm, the highest correlation was found in the L* dimension. All three dimensions had positive correlations (R2 > 0), but only the 1-mm and 4-mm b* readings were very strong. Patient and silicone L*a*b* measurement results showed very little change in the a* axis, while the L* and b* measurements showed more change in their numbers, with changes in depth for all patient silicone samples. Delta E numbers indicated the lowest Delta E at the 1-mm depth and the highest Delta E at the 10-mm depth. All duplicated samples matched their original silicone samples to a degree that visual evaluation could not distinguish any color differences. Using volumetric measurements, a shade guide was developed for all 15 patients. CONCLUSIONS: There was good correlation between the patient's colorimeter measurements and the silicone samples, with the b* color dimension the most reproducible, followed by the L* and the a*. Silicone samples at 6, 8, and 10 mm matched the patient the best, and this study showed that silicone samples can be duplicated successfully if a good patient-silicone match is obtained. Rayon flocking fibers and liquid makeup are effective at matching facial prostheses and can be used to develop a simple shade guide for patient application.

A multicenter longitudinal clinical trial of a new system for restorations.

STATEMENT OF PROBLEM: A new method for fabrication of crowns and fixed partial dentures (Procera system) that involves electric discharge machining and copy milling has been developed. The metal used is unalloyed titanium, which can be processed as a single coping or multiple units joined to a pontic by laser welding. PURPOSE: The single-unit coping or the fixed partial denture (FPD) substructure is then veneered with a low-fusing porcelain. MATERIAL AND METHODS: In this article the clinical application of this technique was evaluated by six major universities in the United States. A total of 114 patients participated in this study, which involved 126 restorations (55 maxillary and 71 mandibular prostheses). There were 179 abutments, of which 73 were crowns and 53 were three-unit FPDs. Surface and color, anatomic form, and margin integrity were assessed 1 month after cementation and at 1 year with the California Dental Association (CDA) quality assessment evaluation system. RESULTS: No statistically significant differences in CDA scores between the 1 month evaluations and the 1 year assessments were found for surface and color (p = 0.68), anatomic form (p > 0.99), or margin integrity (p = 0.57). By use of the lowest ranking in the three categories as the overall quality of the restoration, only 3.3% (two crowns and two FPDs) were not acceptable at the 1-month visit and 4.5% (two crowns and three FPDs) were not acceptable at the 1-year evaluation. At-the 1-month visit 96.6% (114) of the restorations were considered to be satisfactory, whereas 95.5% (107 restorations) were evaluated similarly at the 1-year evaluation. CONCLUSIONS: The Procera system demonstrated, by use of the CDA criteria, its capability to produce quality prostheses that were rated satisfactory more than 95% of the time after insertion and maintained this high rating at least for 1 year.

An evaluation of microwave-polymerized resin bases for removable partial dentures.

PURPOSE: The hardness, porosity, and adaptation of removable partial dentures fabricated with one heat-polymerized denture base resin and two resins designed for microwave polymerization were evaluated. MATERIALS AND METHODS: Five prostheses were evaluated for each resin. Adaptation of the denture bases to the master cast was evaluated by spatial orientation and mean weight of residual impression material. The prostheses were than embedded in epoxy resin and sectioned for evaluation of resin hardness (Knoop hardness) and microporosity. RESULTS: There were no significant differences in the adaptation of the acrylic resin bases for Acron MC and Ch Lucitone. There was no significant difference in the mean Knoop hardness values for any of the resin bases near and away from the metal. None of the denture bases showed porosity greater than 100 microns. CONCLUSIONS: Both resin bases formulated for microwave polymerization were effectively polymerized around metal frameworks without adverse effects on resin hardness or porosity. Justi Denture Base material had poorer base adaptation than the other two resins.

Microleakage of amalgam restorations using dentin bonding system primers.

PURPOSE: To evaluate and compare in vitro microleakage of etched and non-etched Class I amalgam restorations lined with various dentin bonding system primers to amalgam restorations with or without a Copalite liner. MATERIALS AND METHODS: Class I amalgam preparations were made in 140 extracted molars and divided into 14 groups of 10 teeth each. Permite C dispersed phase alloy restorations were placed after the following treatments: Group 1: No liner; Group 2: Lined with two coats of Copalite; Group 3(A): Lined with Amalgambond AA and 3(B): Etched with 35% Ultra-etch and lined with Amalgambond AA; Group 4(A): Lined with Scotchbond Multi-Purpose Primer and 4(B): Etched and lined with the primer; Group 5(A): Lined with ProBond and 5(B): Etched and lined with the primer; Group 6(A): Lined with All-Bond 2 Primer A & B and 6(B): Etched and lined with the primer; Group 7(A): Lined with OptiBond and 7(B): Etched and lined with the primer; Group 8(A): Lined with Permagen Primer and 8(B): Etched and lined with the primer. All primers were applied per manufacturers' specifications. After storage in water for 24 hours, all restorations were polished and then aged in water at 37 degrees C for 90 days. The specimens were then thermocycled for 300 cycles at 5 degrees C and 55 degrees C in basic fuchsin dye with a 30-second dwell time, mounted in epoxy rings, sectioned longitudinally, mesiodistally and buccolingually into four sections, then evaluated at x100 and the extent of dye penetration at the tooth/amalgam interface scored (two scores for each section, eight for each specimen). RESULTS: The unlined and Copalite-lined groups and all non-etched groups showed considerable marginal leakage. All the etched restorations were significantly more effective in reducing microleakage than the non-etched, no liner and Copalite-lined groups. Etching prior to application of the primers is significantly more effective than nonetching, however the effectiveness of the primer alone to seal the dentin needs to be evaluated. Overall, Amalgam-bond AA had the least microleakage of all the groups.

Effect of selected physical properties of waxes on investments and casting shrinkage.

This study evaluated the relationship between flow characteristics, bending strength, and softening temperature of paraffin and dental inlay waxes to casting shrinkage when patterns were invested with a phosphate-bonded investment. This study found that the casting shrinkage decreased as the flow of the wax pattern increased. If a low flow wax is used or if there is a need for a thick pattern, the size of the casting ring should be increased. When wax patterns are formed for cast restorations, it is important to select the type of wax with the most desirable properties for the margin and the occlusal portions. Moreover, to accurately fabricate castings, it is necessary to understand the physical properties of the chosen waxes.

A comparison of three methods for preparing reversible hydrocolloid duplicating material.

This study compared the effects of repeated microwave oven and double-boiler liquefactions and prolonged autoduplicator storage on four physical properties of one reversible hydrocolloid duplicating material. No significant differences were observed between the linear dimensional change and detail reproduction of the three liquefaction techniques. Tear strength differences most clearly distinguished the techniques and effects of aging. Fifteen double-boiler remeltings produced tear strength values lower than those recorded for material stored in an autoduplicator for 2 weeks. Thirty microwave melting cycles still produced tear strength values equivalent to that of the autoduplicator material. After 30 melting cycles the compressive strengths of the microwave and double-boiler materials were inferior to that of the stored autoduplicator material.

Effect of two opaquing techniques and two metal surface conditions on metal-ceramic bond strength.

The optimal conditions for opaquing techniques during porcelain application have not been confirmed. In this study the metal-ceramic bond strength was measured among one porcelain and three dental alloys, namely a gold-platinum-palladium alloy, a silver-free gold-palladium alloy, and a base metal alloy, with two opaquing techniques (a single masking layer versus a thin overfired layer followed by a second masking layer). In addition, the opaque porcelain was fired over an oxidized and nonoxidized alloy surface for the silver-free gold-palladium alloy. No significant differences in bond strength were recorded between the two opaquing techniques with the gold-platinum-palladium and base metal alloys. There was no substantial differences between the two opaquing techniques when opaque was applied over an oxidized gold-palladium alloy surface and bond strengths were substantially greater over an oxidized surface. However, when the opaque was applied to a nonoxidized gold-palladium surface the two-layer technique created a significantly greater bond strength.

[Humoral immune response to the proteins of an antimeningococcal BC vaccine in a trial carried out in Antioquia, Colombia]. / Respuesta inmune humoral a las proteínas de una vacuna antimeningocócica BC en un ensayo realizado en Antioquia, Colombia.

This study evaluated the humoral response to protein components of the Cuban-produced vaccine against serogroups B and C meningococcus, VA-MENGOC-BC, in adults and children 1 to 5 years old. The trial was conducted in an area of the Department of Antioquia, Colombia, in which an elevated incidence of meningococcal disease had been recorded. The serum anti-vaccine-protein response was studied before (T0) and after (T1) vaccination by means of enzyme-linked immunosorbent assay (ELISA), and lytic capacity was evaluated through the bactericidal antibodies test (BAT). The ELISA was performed before and after vaccination on the sera of 407 adults and 213 children. Lytic capacity against Cuban meningococcal strain B:4:P1.15 was studied with BAT in paired sera from 90 adults and 114 children. The two techniques showed a statistically significant response (P < 0.01) to the vaccine, in both adults and children. Of the total number of subjects tested with ELISA, 81% showed an immune response to the vaccine (T1/T0 > or = 2) (95% confidence interval, CI95%: 78% to 84%); among children, immune response was 91% (CI95%: 87% to 94%). All the children 1 year of age (n = 7) responded. Seroconversion (T1/T0 > or = 4), as shown by ELISA, was 80% among adults (CI95%: 73% to 86%) and 90% among children (CI95%: 83% to 100%). BAT demonstrated seroconversion in 85% (CI95%: 78% to 92%) of subjects who had been seronegative before vaccination, 85% of the adults (CI95%: 76% to 95%) and 84% of the children (CI95%: 72% to 96%). Seroconversion among children 3 and 4 years of age was 80%. The group of sera from children 1, 2, and 5 years old available for study with BAT was too small for meaningful statistical analysis; all of them seroconverted. In 20 sera chosen randomly for study of their bactericidal activity against all the strains isolated from patients in Colombia (B:4:P1.15, B:8:P1.nt, and two strains of serogroup C), seroconversion was found in all 20 cases. These results give reason to think that vaccination in this group produced an effective immune response, as measured serologically, and this belief is corroborated in practice by the lack of any cases of meningococcal disease through September 1994 among the people vaccinated.

A comparison of the marginal and internal adaptation of titanium and gold-platinum-palladium metal ceramic crowns.

The marginal and internal adaptation of metal ceramic crowns fabricated by electrical discharge machining and conventional metal ceramic alloys were compared. The crowns were cemented using zinc phosphate cement, embedded in epoxy resin, and sectioned in two planes: diagonal and buccolingual. The crowns were then measured at nine sites. The results showed that there were no statistical differences between the external marginal opening of the titanium and the gold-platinum-palladium crowns. The overall marginal discrepancies for the restorations in this study were 61 microns (+/- 34 microns) for the titanium metal ceramic crowns and 47 microns (+/- 17 microns) for the gold-platinum-palladium metal ceramic crowns.

The effect of finish line form and luting agent on the breaking strength of Dicor crowns.

Molar teeth were prepared to a standardized cylindric form using a lathe. Dicor crowns were luted on these preparations using zinc phosphate, glass-ionomer, and resin cements. The crowns were thermocycled and subjected to fracture loading to compare the effect of the different luting agents on fracture strength. Five finishing lines were used to determine if resin cement and associated bonding procedures could counteract the negative effect certain finish lines produce on all-ceramic crowns. When resin cement was used in conjunction with restoration and tooth precementation bonding treatments, the crowns were significantly stronger than when glass-ionomer or zinc phosphate cements were used. No difference in strength was found between the five finish lines when the crowns were cemented with resin and associated bonding procedures.

Fractal dimension analysis of aluminum oxide particle for sandblasting dental use.

Aluminum oxide particles are commonly used as a sandblasting media, particularly in dentistry, for multiple purposes including divesting the casting investment materials and increasing effective surface area for enhancing the mechanical retention strengths of succeedingly applied fired porcelain or luting cements. Usually fine aluminum oxide particles are recycled within the sandblasting machine. Ceramics such as aluminum oxides are brittle, therefore, some portions of recycling aluminum oxide particles might be brittle fractured. If fractured sandblasting particles are involved in the recycling media, it might result in irregularity metallic materials surface as well as the recycling sandblasting media itself be contaminated. Hence, it is necessary from both clinical and practical reasons to monitor the particle conditions in terms of size/shape and effectiveness of sandblasting, so that sandblasting dental prostheses can be fabricated in optimum and acceptable conditions. In the present study, the effect of recycling aluminum oxide particles on the surface texture of metallic materials was evaluated by Fractal Dimension Analysis (FDA). Every week the alumina powder was sampled and analyzed for weight fraction and contaminants. Surface texture of sandblasted standard samples was also characterized by FDA. Results indicate very little change in particle size, while the fractal dimension increased. Fractal dimension analysis showed that the aluminum oxide particle as a sandblasting media should be replaced after 30 or 40 min of total accumulated operation time.

A receiver operating characteristic (ROC) curve analysis of a model of mental health services use by Puerto Rican poor.

In this study, the contribution of four distinct domains of the Help Seeking-Decision Making model to predicting the use of mental health services is examined. Using a proposed methodology the authors assess the relevance of this model and its domains to mental services planning. The methodology combines logistic regression analysis and receiver operating characteristic (ROC) curves. Logistic regression analysis allows us to examine the individual variables of the model and generate predictions about use. ROC curves allow us to compare and interpret the relative contribution of a predisposing domain, a physical and mental health domain, an enabling-restrictive domain, and an organizational domain in correctly classifying users and nonusers of mental health services. The physical and mental health domain yielded a Somer's D-statistic of 0.7, which corresponds to an 85% correct classification of randomly selected pairs of users and nonusers. The study findings suggest that comparing ROC curves helps to describe and interpret the domains of the model that are relevant for making predictions about who will or will not use mental health services during a 1-year period.

Effects of environmental factors on maxillofacial elastomers: Part IV--Optical properties.

The optical properties of four currently used and two recently introduced maxillofacial prosthetic materials were evaluated after the materials were subjected to the following seven environmental variables: natural weathering; normal aging; two types of adhesives; two types of cleaning agents; and cosmetics. Optical density and color changes were evaluated. The currently used silicones Silastic 4-4210 and Silastic 4-4515, Medical Adhesive type A material, and polyurethane all showed more changes in color and optical density than the newly introduced silicone A-102 material.