Volatilization of components from and water absorption of polyether impressions.

OBJECTIVE: To evaluate the accuracy of stone dies produced from impressions with polyether impression materials and a vinyl polysiloxane reference material after prolonged storage at 0, 50, or 100% relative humidity. METHODS: Impressions were taken with light and heavy-bodied types of the polyethers P2 (P2L/H; Heraeus Kulzer) and Impregum (IML/H; 3M ESPE) and vinyl polysiloxane Flexitime (FLL/H; Heraeus Kulzer) from a truncated steel master cone in cylindrical trays giving 4 mm layer thickness at the prominence line. Impressions were taken at 23 degrees C, and stone dies were poured after 1, 2, 3, 4, or 5 days storage at 23 degrees C and 0, 50, or 100% RH. Accuracy was determined as discrepancy between a steel ring with accurate fit on the master cone and the stone die and expressed as base diameter deviation Deltad (microm). One-way ANOVA and Duncan's post-hoc test were used for statistical data analysis (p<0.05). RESULTS: P2L/H showed significant Deltad increase (30-240 microm) depending on storage time and humidity (p<0.05). Dies from IML/H at 0% RH were 90 through 180 microm enlarged, at 50% RH the maximum diameter increase was 60 microm, and at storage in 100% RH all dies were 25-120 microm smaller (p<0.05). Dies from FLL/H showed maximum Deltad deviations (55 to -10 microm). CONCLUSIONS: P2 impressions release volatile substances during storage and should preferably be poured within less than 24 h. Impregum absorbs water and should be stored at <50% humidity. The accuracy of Flexitime is scarcely affected by storage time or by ambient humidity.

Self-etching primers--an alternative to the conventional acid etch technique?

MATERIAL AND METHODS: The aim of the present in vitro study was to evaluate the bonding capacity of three self-etching primers (Clearfil SE Bond [SE], Clearfil Liner Bond 2V [CLB], Novabond [NOVA]) to enamel. Two adhesive systems with a separate phosphoric acid etching procedure (Gluma Comfort Bond [GLU], Kurasper F [KU]) served as controls. 60 human incisors were used to evaluate shear bond strengths of composite cylinders to enamel. RESULTS: Significant differences were found between the groups (p < 0.001). The mean value for groups GLU, KU, CLB and SE was 24 MPa. The shear bond strength recorded for the Novabond system was significantly lower (17 MPa). CONCLUSION: The results of the present investigation indicate that enamel bonding especially with the self-etching primers CLB and SE is as effective as conventional phosphoric acid etching.

4-META as an acidic monomer in an all-in-one experimental adhesive.

This article describes a clinical study of an experimental, all-in-one, self-etching priming enamel and dentin adhesive. This new compound is a hydroxyethylmethacrylate (HEMA)-free resin mixture of urethane dimethacrylate (UDMA) and 4-methacryloxyethyl trimellitate anhydride (4-META) dissolved in acetone and water. The pH of the adhesive solution is 2.2, which classifies this material as moderately strong. Bond strengths to enamel and dentin are approximately 20 MPa. The marginal inspection of bonded resin composite restorations in 3.5-mm wide, cylindrical, butt-joint dentin cavities reveals gap-free intact margins in 6 of 8 cases. Scanning electron microscopy analysis of the bonding interface to enamel shows a shallow microretentive etching pattern, and dentin is hybridized to a depth of approximately 1 micron. The fracture morphology analyzed on debonded shear strength specimens illustrates cohesive failure in resin close to the enamel and dentin bonding interfaces.

Microtensile bond strength evaluation of three adhesive systems in cervical dentin cavities.

PURPOSE: To evaluate the influence of the orientation of dentinal tubules on the bonding performance, microtensile bond strengths (MTBS) to dentin in cervical dentin cavities were measured for three current bonding systems. MATERIALS AND METHODS: Wedge-shaped cervical cavities (5 x 5 x 3 mm) prepared in extracted human premolars were treated with one of the three adhesive systems, Gluma One Bond, UniFil Bond and Mega Bond in combination with a hybrid-type resin composite. After storage in water for 24 h, the teeth were sectioned longitudinally through the restoration for determination of MTBS, either at the coronal or at the apical wall of the lesion. In an additional group, either the coronal or the apical walls were coated with vaseline prior to adhesive bonding and insertion of the resin composite, and then MTBS was measured. RESULTS: MTBSs (mean +/- SD, MPa) to coronal and apical dentin were 35.1 +/- 19.1 and 16.4 +/- 7.9 for Gluma One Bond, 37.7 +/- 11.5 and 18.6 +/- 8.6 for UniFil Bond, and 27.0 +/- 15.2 and 30.3 +/- 17.0 for Mega Bond, respectively. MTBS to the coronal wall was higher than to the apical wall (p < 0.05) with Gluma One Bond and UniFil Bond, whereas no difference was found with Mega Bond. With all three systems, vaseline coating had no effect on the bond strength (p > 0.05), indicating that the wall-to-wall contraction stresses exerted in the noncoated group had no influence on the bond strength generated. CONCLUSION: In cervical dentin cavities, apart from the individual adhesive's bonding capacity, the dentinal tubular orientation may have an influence on the bond strength.

Rewetting strategies for bonding to dry dentin with an acetone-based adhesive.

PURPOSE: The objective of this study was to investigate the effect of rewetting agents on bonding to etched and air-dried dentin. MATERIALS AND METHODS: For shear bond strength testing (SBS), the proximal surfaces of 90 molars were ground on wet SiC paper to prepare them for resin composite bonding with Gluma One Bond (Heraeus Kulzer, Germany). Dentin cavities were cut (Ø 3.5 mm, 1.5 mm deep) in 60 molars and restored with Gluma One Bond/Charisma for evaluation of the marginal performance (MGW). The adhesive was applied on acid-etched and rinsed dentin after the following pretreatment techniques: A: moist; B: 15 s air dried; C through F: 15 s air dried, followed by 30 s rewetting with C: water; D: 35% HEMA; E: Gluma Primer; F: 5% glutardialdehyde; G through J: as C through F, but followed by 15 s air drying. SBS data were analyzed with ANOVA and Tukey's test, and MGW with Kruskal-Wallis and Mann-Whitney U-test (alpha = 0.05). RESULTS: Shear bond strengths of groups A and B were 20.3 and 1.1 MPa, respectively. The Tukey ranking of SBS results was [A=C=D=E] > [C=D=E] > [C=D=I] > H > [F=J] > [B=G]. Groups A, C, D, E, H, and I with 3 or 4 gap-free restorations each showed no differences in MGW (p > 0.05). In contrast, no gap-free specimens were found in groups B, F, G, or J, and marginal gaps were significantly larger (p < 0.05). CONCLUSION: Rewetting of dried dentin with water, 35% HEMA, or Gluma Primer resulted in effective bonding. Excessive drying after rewetting had no compromising effect on adhesion in the HEMA- and GLUMA-primed groups, whereas the water and glutardialdehyde-treated groups showed poor bonding.

Postadjustment polishing of CAD-CAM ceramic with luminescence diamond gel.

PURPOSES: (1) to investigate by SEM and profilometry the effectiveness of Luminescence diamond polishing gel on machinable ceramic after adjustment grinding with different grit diamond finishing burs, and (2) to define a simple, time-saving ceramic finishing and polishing technique for clinically satisfactory results. MATERIALS AND METHODS: Discs, 3 mm thick, were cut from Vita Mark II CAD-CAM ceramic and ground to a uniform surface finish on 600 grit wet SiC paper. Five specimens in each of the seven groups below were finished unidirectionally by a sweeping mode with the following Two Striper MFS diamond burs: 1. MF1 (45 microm); 2. MF2 (25 microm); 3. MF3 (10 microm); 4. MF1 + MF2; 5. MF1 + MF3; 6. MF2 + MF3; 7. MF1 + MF2 + MF3. Then, Luminescence diamond polishing gel was dispensed on a mandrel-mounted felt applicator and applied at 10,000 rpm for 60 s, and after dipping in water for another 60-s sequence. Surface roughness was determined for each step with a stylus-fitted surface analyzer. On each specimen five parallel tracings (evaluation length 4.0 mm and cut-off length 0.8 mm) were made 1 mm apart. Ra and Rz values were recorded as roughness parameters. Data was subjected to one-way ANOVA and Tukey's multiple comparison test at a significance level of alpha = 0.05. One additional sample for each grinding and polishing step in each of the seven groups was produced for SEM analysis. RESULTS: Diamond polishing after MF1 finishing reduced Ra and Rz significantly from 1.75 to 0.79, and from 10.0 to 4.09 microm, respectively, whereas the Ra and Rz reduction after MF3 finishing and diamond polishing were from 0.64 to 0.49 and from 4.31 to 1.81 microm. The polished surface roughness of specimens prefinished with MF2 or MF3 burs alone or as the final step after preceding grinding with coarser grits was not significantly different. The average Ra and Rz values were 0.42 microm and 1.73 microm. SEM photographs confirmed the uniformity of the surface finish in these groups. The second polishing sequence did not significantly improve the smoothness obtained with the first cycle.

Bonding efficiency of single-bottle enamel/dentin adhesives.

PURPOSE: To compare the bond strength to dentin of the single-step enamel-dentin adhesive Etch & Prime 3.0 (EP3) to that of two-step systems Clearfil Liner Bond 2 (CL2), which includes a self etching primer and Gluma One Bond (GL1), a one-bottle bonding agent, intended for use with the total etch technique. MATERIALS AND METHODS: Shear bond strength after a 24-hour water storage was determined for 10 specimens each bonded with the three adhesives. Maximum, gap widths were recorded microscopically after a 10-minute water storage along the margins of resin-based composite restorations bonded with each adhesive in cylindrical dentin cavities (3.5 mm wide and 1.5 mm deep). Marginal micro-morphology of the specimens bonded with EP3 was observed with the SEM. RESULTS: EP3 had an enamel bond strength similar to that of the other materials, but its bond strength to dentin was approximately only 50% of the bond strength of the two other adhesives. Similarly, the marginal performance of resin restorations bonded with EP3 in cylindrical dentin cavities was poor (average maximum gap width 5 microns) irrespective of the curing conditions tested with EP3. CL2 showed significantly smaller gaps (2 microns) along the cavity margin than EP3, whereas in the GL1 group in 7 of the 10 restorations inspected perfect gap-free margins were observed. An SEM investigation of different steps throughout the EP3 application and processing gave evidence that the product apparently conditions and wets enamel and dentin quite effectively, and that an approximately 0.5 micron thick hybrid layer is formed as a coupling zone between dentin (intertubular and peritubular) and restorative resin.

Practitioner variability effects on dentin bonding with an acetone-based one-bottle adhesive.

PURPOSE: The objective of this study was to investigate the effect of operator variability on the marginal performance of resin composite restorations bonded with an acetone-base one-bottle adhesive in standardized dentin preparations. MATERIALS AND METHODS: Five general practitioners were recruited for this trial. In the first group, each dentist received six extracted human teeth with dentin preparations (Ø 3.5 mm, 1.5 mm deep), cut in flatground proximal dentin, and original packages of Gluma One Bond adhesive and Charisma resin composite (Heraeus-Kulzer, Werheim, Germany) including instructions for use. For the second group, the operators were orally instructed, emphasizing the importance of the moist technique, before they received another six teeth for restoration with the same materials. Finally, a third group of six preparations was restored in order to evaluate a possible training effect. The restored teeth were stored in a hygrophor prior to removal of excess material and microscopic determination of the maximum marginal gap width (MGW). Statistical analyses were performed with the Kruskal-Wallis and Wilcoxon tests at p < 0.05. RESULTS: Apart from two samples, preparation margins in the first test group showed gaps between 1 and 12 microns. In the second and third groups, 15 and 16 restorations were gap free, respectively. Significant interoperator variation was found in the first group only. Marginal performance of group 1 restorations was significantly inferior to groups 2 and 3, which were not different (p = 0.79). CONCLUSION: Application of the one-bottle adhesive is technique-sensitive and requires meticulous attention to the instructions.

Salivary contamination during bonding procedures with a one-bottle adhesive system.

OBJECTIVE: The effect of salivary contamination of enamel and dentin on bonding efficacy of an experimental one-bottle resin adhesive was investigated. METHOD AND MATERIALS: The adhesive was a light-curing urethane dimethacrylate/hydroxyethyl methacrylate/4-methacryloxyethyl trimellitate anhydride mixture dissolved in acetone. Evaluation parameters were shear bond strength and marginal gap width in a dental cavity. Apart from a control group without contamination (group 1), etched enamel and dentin were (2) contaminated with saliva and air dried; (3) contaminated, rinsed, and blot dried; (4) coated with adhesive, contaminated, rinsed, and blot dried; (5) coated with adhesive, light cured, contaminated, rinsed, and air dried; or (6) treated as in group 5, with additional adhesive application after air drying. RESULTS: There was no negative effect in groups 3 and 4, compared with control. Air drying after salivary contamination (group 2) resulted in low shear bond strengths and wide marginal gaps. Contamination of the cured adhesive layer (groups 5 and 6) had no adverse effect on enamel shear bond strengths, but resulted in 50% reduced dentin shear bond strengths and wide marginal gaps. CONCLUSION: The one-bottle adhesive system is relatively insensitive to salivary contamination, provided that the contamination occurs prior to light curing of the adhesive and is carefully rinsed and blot dried. Salivary contact after adhesive curing must be avoided.

Detection of osteomyelitis in the neuropathic foot: nuclear medicine, MRI and conventional radiography.

The diagnostic efficacy of (1) combined three-phase bone scintigraphy and In-111 labeled WBC scintigraphy (Bone/WBC), (2) MRI, and (3) conventional radiography in detecting osteomyelitis of the neuropathic foot was compared. Conventional radiography was comparable to MRI for detection of osteomyelitis. MRI best depicted the presence of osteomyelitis in the forefoot. Particularly in the setting of Charcot joints, Bone/WBC was more specific than conventional radiography or MRI.

Commercial sector can improve access.

PIP: This article discusses the improved accessibility to family planning (FP) services made possible by expanding services among private physicians and through social marketing in developing countries. Encouraging private sector (PS) FP is a way to ease the caseload of public FP facilities and creating the potential for attracting more lower-income clients. Few developing countries have a "viable commercial market" for contraceptives. Commercial success depends upon a secure supply of FP supplies, well-trained providers, and consumer demand. Consumers want affordable, high-quality, and convenient services. Governments must ensure that regulations do not hamper PS programs. Public and private programs should not compete in ways that are counterproductive. The commercial sector includes private physicians, clinics, pharmacies, or hospitals without public subsidies. Public funding might be used to encourage PS distribution, especially condoms and messages about HIV and sexually transmitted disease prevention. Messages may target specific audiences and promote an appealing logo and packaging. SOMARC in Turkey promotes a network of commercial health care facilities that offer high quality FP at affordable prices. The model includes provider training, quality of care monitoring, marketing, a hotline, posted prices, and prices set by consumer affordability surveys. This model is being tried in both Nepal and the Philippines. Commercial marketing has been successful in Latin America, North Africa, and the Middle East. Commercial expansion and survival is dependent upon the satisfaction of consumer preferences for convenience, greater access, better confidentiality, and quality. Examples from Zimbabwe and Romania are used to show strategies for training private providers. Private providers will become involved, for instance, by offering targeted training programs.^ieng

Cost analysis serves many purposes.

PIP: This article discusses the utility of performing cost analysis of family planning (FP) personnel resources by relying on a system analysis framework in developing countries. A study of a national provider that distributes 16% of all FP services in Mexico found that more efficient use of staff would increase the number of clients served. Nurses and doctors worked slightly more than 6 hours/day, and 38% of a nurse's time and 47% of a physician's time was spent in meetings, administrative duties, unoccupied work time, and personal time. The Mexican government proposed increasing the work day to 8 hours and increasing to 66% the portion of the work day spent on direct client activity. With this change, services would increase from 1.5 million couple-years of protection (CYP) to 1.8 million CYP in 2010, without additional staff, and CYP cost would decline. CYP costs could potentially be reduced by increasing the number of contraceptive units provided per visit and switching from a 1-month- to a 3-month-duration injectable contraceptive. A Bangladesh study found that CYP costs could be reduced by eliminating absenteeism and increasing work time/day by 1 hour. Cost studies can address specific human resource issues. A study in Thailand found that Norplant was more expensive per CYP than injectables and the IUD, and Norplant acceptors were willing to switch to other effective modern methods. The Thai government decided to target Norplant to a few target groups. Staff time use evaluations can be conducted by requiring staff to record their time or by having clients maintain records of staff time on their health cards. The time-motion study, which involves direct observations of how staff spend their time, is costly but avoids estimation error. A CEMOPLAF study in Ecuador found that 1 visit detected almost as many health problems as 4 visits. Some studies examine cost savings related to other services.^ieng

Ways to evaluate staff.

Evaluating how staff use their time can be done in different ways. One approach is to ask staff members to record how they spend their time. Another way, called "patient flow analysis," collects time data from clients, by having each staff member enter time of arrival and departure on a form carried by the client as the client moves through the clinic. Yet another approach, more expensive and time-consuming, is known as a "time-motion" study, based on actually observing how personnel spend their time. In general, the time-motion approach to cost analysis, in which staff are observed, tends to be more accurate, says John Bratt of FHI, who has coordinated several large cost studies. Unproductive staff time tends to be recorded more accurately using this approach. A recent study compared the provider interview and patient flow analysis approaches to actual time observed in clinics, a time-motion model. "The provider interview approach was particularly weak, substantially overestimating contact time with clients and underestimating nonproductive time," says Bratt, who coordinated the study with the Population Council. "The magnitude of error in these estimates calls into question the validity of studies that use provider interviews for measuring staff time." The researchers were hoping the study would provide a way to substitute less costly methods of time measurements for time-motion studies. "But the outcome indicates that these other methods perform far less well than does the time-motion method," Bratt says. "We are now looking at ways to use time-motion in a small number of sites and extrapolate from that to the full system. But we need to do more research to see if that is as reliable."

Condom use increasing.

PIP: Condom use is central to the prevention of AIDS among people at risk for contracting HIV. As such, condom use is increasing dramatically even though many men say that they do not like using them. Condom sales through social marketing campaigns have increased dramatically in some countries, where tens of millions of condoms are sold annually. For example, during the period 1991-96, annual social marketing sales increased about five-fold in Ethiopia to 21 million, and nine-fold in Brazil to 27 million. These sales reflect the success of condom social marketing campaigns in making condoms accessible and largely affordable. There is also a greater general awareness of AIDS than there used to be, and communication campaigns have shown that condoms are an effective solution. More condoms still need to be used in the ongoing struggle against HIV/AIDS. The author discusses the factors which affect the limited acceptance of condoms, condom use outside of marriage, social marketing, and family planning programs.^ieng

Behavior affects consistent use.

PIP: Condoms must be used correctly and consistently in order to prevent sexually transmitted diseases (STDs) and pregnancy. However, consistent use demands sustained behavior patterns. In a project with International Planned Parenthood Federation affiliates in Brazil, Honduras, and Jamaica, the counseling of women has moved away from emphasizing contraceptive methods, side effects, and correct use, to the more broad context of women's sexuality and risk of STD infection as a means of promoting behavior change. Providers use a sexuality-based approach in which they confer with women about their current sex partners, past partners, whether their partners travel for work, whether they think their partners may have other sex partners, and how those factors relate to the risk of STD infection. The project has also aggressively taught men about STDs and condom use, and involves men in counseling. One study has found that people who choose condoms as their main contraceptive method need more counseling than people who use condoms as a backup method, since primary users may have underestimated the difficulty of using condoms at every act of sexual intercourse. Furthermore, counseling appears to increase condom use when it involves both men and women in a monogamous relationship.^ieng

Do condom characteristics influence use?

PIP: Loss of sensation, inability to maintain an erection, discomfort, and interruption of foreplay are some of the major reasons why people do not use condoms. Research has found that condom users prefer lubricated condoms, because they can reduce the level of discomfort and make condoms easier to use. In accordance with these findings, most condoms are now pre-lubricated. While changes in condom shape and thickness may also heighten users' satisfaction with condoms, research has generally found that different materials, widths, and latex formulations have little effect upon consumer preference. Limited research suggests that many men prefer comparatively thin condoms, but more research is needed. Men who evaluated a latex condom which fits loosely over the tip of the penis reported enjoying the experimental condom at least as much as they did the standard condom. Men involved in two studies comparing the use of latex and polyurethane condoms reported that while the latex condom was easier to put on, the penis was more often constricted than it was in the polyurethane device. Both men and women reported a higher degree of condom breakage and stretching out of shape with the polyurethane condom, but comparatively less sexual stimulation with the latex condom. One polyurethane condom, the Avanti, is currently available in the US and 4 European countries.^ieng

Attracting men to vasectomy.

PIP: There is far less information available for men about vasectomy than there is available for women about comparable contraceptive services. Also, men do not have medical check-ups on a regular basis, and therefore have less contact with medical practitioners during which vasectomy could otherwise be discussed. Vasectomy needs to be promoted in order for men to learn about and accept it as their contraceptive method of choice. To that end, Marie Stopes International (MSI) launches a vasectomy promotion campaign annually which includes advertising in local newspapers and upon billboards at football stadiums. The campaigns use light-hearted and bold ideas, with some shock value. This approach helps to relax men who otherwise tend to be wary of both the surgical procedure and subsequent consequences of vasectomy. Prevailing social norms should, however, guide the content of promotional campaigns. The UK is one of only a few countries in the world where about the same proportions of men and women use sterilization; 16% of men and 15% of women have been sterilized. A MSI campaign in the UK which began during fall 1997 prompted an increase in the number of inquiries about vasectomy at the Marie Stopes Vasectomy Clinic. Promotional campaigns in developing countries have also been successful. It is also important that campaigns be put in the larger context of promoting all contraceptive methods.^ieng

Male responsibility for reproductive health. Introduction.

PIP: Before the advent of the oral contraceptive pill, men were more involved in family planning and other aspects of reproductive health. Then, if a couple wished to practice family planning, they were largely limited to withdrawal, periodic abstinence, and condom use, all practices which require the man's participation. Hormonal methods for women and the subsequent development of IUDs and modern surgical sterilization fostered the development of a family planning services community focused upon women rather than men. The challenge is now to increase the degree of male responsibility for family planning by expanding services in ways which protect the reproductive health of both men and women, and by encouraging greater sensitivity to gender issues. Adding reproductive health services for men can be done without reducing the level of services available for women. However, while PROFAMILIA clinics, which offer a wide range of male reproductive health services, have found ways to encourage male participation, an enormous gap exists between the rhetoric of promoting male involvement and the actual realities of female-oriented reproductive health programs. Obstacles include men's reluctance to use services, lack of knowledge among men about their own and women's sexuality, lack of communication by men about sexuality in their relationships, male beliefs in sexual myths, health providers' and false assumptions and generalizations about men. The authors discuss the need to encourage men to support women's contraceptive choices, to increase communication between partners, to increase the use of male methods, to improve men's behavior for the prevention of STDs, to address men's reproductive health needs, and to encourage men to become more aware of related family issues.^ieng

USAID recommendations.

PIP: US Agency for International Development (USAID) recommendations for providing quality family planning services include providing the client's preferred method, if available and appropriate; treating the client with respect; personalizing counseling to specific situations; being interactive and responsive to clients' questions; focusing upon a client's chosen method; and using and providing memory aids. Key information to help clients choose methods should include effectiveness, side effects and complications, advantages and disadvantages, how to correctly use a method, when to return for follow-up or re-supply, and whether or not it prevents HIV and other sexually transmitted diseases.^ieng

Guidelines require comprehensive steps.

PIP: In recent years, almost 50 developing countries have begun developing new or revised national guidelines on family planning services. Once these guidelines are written, they must be disseminated, including training providers about how and why to use them. They must also be regularly updated, since new scientific findings about contraception or other reproductive health issues may influence procedures and other policies. Clients must be made aware of their rights under the guidelines. It is important that a comprehensive approach be taken to implementing the guidelines, involving training, educating, policy-making, empowering clients, and addressing cultural values. Guidelines also need to be institutionalized into training at schools of medicine, nursing, and pharmacy. Such steps can take years to accomplish. International recommendations are presented, followed by a discussion of provider practices and encouraging adherence.^ieng