Luteal phase support with estrogen in addition to progesterone increases pregnancy rates in in vitro fertilization cycles with poor response to gonadotropins.

In this study, our objective was to determine the effect of adding estradiol hemihydrate (E2) to progestin (P) for luteal phase support on pregnancy outcome in in vitro fertilization (IVF) cycles with poor response to gonadotropins. Ninety-five women with poor ovarian response who underwent controlled ovarian hyperstimulation (COH) with gonadotropin releasing hormone (GnRH) agonist or GnRH antagonist plus gonadotropin protocol for IVF were prospectively randomized into three groups of luteal phase support after oocyte retrieval. Group 1 (n = 33) received only intravaginal progesterone gel (Crinone 8% gel). Group 2 (n = 27) and Group 3 (n = 35) received intravaginal progesterone plus oral 2 and 6 mg estradiol hemihydrate, respectively. Main outcome measures were overall and clinical pregnancy rates (PRs) per patient. Serum LH, E2 and P levels at 7th and 14th days of luteal phase were also measured. Overall and clinical PRs were significantly higher in 2 mg E2 + P than P-only group (44% versus 18% and 37% versus 12.1%, respectively). There were no statistically significant differences between 6 mg E2 + P versus P-only and 2 mg E2 + P versus 6 mg E2 + P groups regarding PRs. Addition of 2 mg/day E2 in addition to P for luteal support significantly increase overall and clinical PRs in cycles with poor response to gonadotropins after IVF.

Influence of surgical technique, implant shape and diameter on the primary stability in cancellous bone.

Achievement of primary stability during surgical placement of dental implants is one of the most important factors for successful osseointegration depending on various anatomical, surgical and implant-related factors. Resonance frequency analysis (RFA) has been shown as a non-invasive and objective technique for measuring the stability of implants. The aim of this study was to evaluate the effect of some surgical and implant-related factors in enhancing primary stability and to estimate a correlation between RFA and insertion torque (IT) in proximal regions of cow ribs representing cancellous bone. Fifteen implant beds were prepared in the most proximal region of six fresh cow ribs. Ninety implants with three different shapes and two different diameters were placed with two different surgical techniques, and the primary stability was compared using RFA and IT. Significantly higher RFA and IT values were achieved when under-dimensioned drilling was used as the surgical method (P<0·01); significantly higher IT values were obtained with the use of wider implants (P<0·01) and partially conical Astra Tech implants showed the highest IT values (P<0·01). When all the implants were considered, significant correlations between the IT and RFA values were noted (%40·6, P<0·05). Partially conical implants with a wide diameter to be placed with the modified surgical technique proposed appear to be useful in enhancing the primary stability in cancellous bone.

Comparison of tensile and peel bond strengths of resilient liners.

Previous studies have shown little agreement between the test methods used to assess the bond strength and the mode of failure of resilient liners. This study evaluated the bond strength characteristics of resilient liners by means of 180-degree peeling and butt tensile strength testing. Seventy-two specimens were divided into peel bond and tensile bond specimen groups and were then subdivided into four test groups to evaluate each resilient liner. Tests were conducted with an Instron universal testing machine at a cross-head speed of 2 mm/minute for the tensile specimens and 5 mm/min for the peel specimens. Tensile bond strength and peel bond strength varied significantly among resilient liners except between Novus and Palasiv-62 liners in tensile testing. The mode of failure of Molloplast-B and Novus liners was significantly different between the tensile bond and peel bond test methods. It was concluded that bond strength characteristics can vary according to the test method used.

Tensile bond strength of a soft lining with acrylic denture base resins.

Bonding of different soft lining materials has been widely investigated, but there is little work on the effect of using different denture base resins. This study investigates the bonding of Molloplast-B (a heat-cured, silicone soft lining material) and five commercial acrylic denture base materials of different types (Pacton, Lucitone, Meliodent, Ivocap and Compresin). The lining was processed against all the resins cured and Pacton, Lucitone and Meliodent uncured. In the cured specimens, Lucitone, Meliodent and Compresin demonstrated cohesive failure, whereas Pacton and Ivocap demonstrated part-adhesive and part-cohesive failure. All three sets of uncured specimens demonstrated adhesive failure. It was concluded that pre-curing, roughening and treating with Primo adhesive gives a better bond.

A silicone rubber spacer used to determine the optimum thickness for hard and resilient materials in complete dentures.

When making a denture with a resilient lining, the problem of controlling the thickness of the resilient lining material is eliminated by use of a spacer. However, controlling the thickness of the hard acrylic resin denture base in these dentures remains a problem and may increase the possibility of fracture. When limited denture space is available, the portions of the denture base subject to fracture should have an accurate if not equal share of the resilient lining material and the hard acrylic resin material. This procedure will minimize the fracture problem of dentures made with resilient lining and is an alternative to conventional spacer procedures.