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Notes: We have developed a dynamic calorimeter, which can measure thermal properties of a wire or planar sample as a function of frequency over the range of five decades, 0.01 Hz–1 kHz. We have used this calorimeter to study the frequency dependence of the specific heat of gadolinium near the Curie point. There is an indication that the specific heat peak associated with the magnetic phase transition may depend on the measuring frequencies.

Notes: We show how to measure dynamic specific heat and thermal conductivity of a solid or liquid sample using the 3ω technique, which is an ac-modulation method where we use a heater simultaneously as the sensor. By varying the width of the heater relative to the thermal decay length, one can choose the proper regime to measure thermal conductivity or specific heat. The technique is applied to window glass and the results confirm the validity of the method. Experimental results for potassium dihydrogen phosphate crystal demonstrate the first-order transition at the Curie point, and the dynamic specific heat of supercooled liquid potassium–calcium nitrate is shown. © 1996 American Institute of Physics.

Notes: We have developed a continuous cooling method, as a simple modification of adiabatic calorimetry which typically operates in the heating mode, with the capability of varying the scanning rate in the range of 0.01–2 K/min. This method allows us to determine the absolute value of specific heat of a liquid or solid during cooling as well as during heating in the temperature range between 100 and 400 K. The typical specific heat data of a supercooled liquid [Ca(NO3)2]0.4(KNO3)0.6 agree well with results by other methods. © 1996 American Institute of Physics.

Notes: We developed an ac microcalorimeter utilizing the Peltier effect of a thermocouple junction as an ac power source. This Peltier microcalorimeter allows us to measure the absolute value of the heat capacity of small samples with submilligrams of mass. The performance of the microcalorimeter was checked in the temperature range of 15–420 K with α-Al2O3 samples of 0.54 and 2.25 mg. The absolute accuracy was ±3% for the range of 30–150 K and ±1% for 150–420 K. The precision was better than 0.5% in the whole temperature range. © 2000 American Institute of Physics.

Notes: Abstract. The present study was performed in order to examine the composition of the connective tissue that forms an attachment to a dental implant. 6 beagle dogs were used. All mandibular premolars were extracted. After 3 months of healing, 6 fixtures – 3 in each side of the mandible – (Astra Tech Implants, Dental SystemA TiO blast ; Astra Tech AB, Mölndal, Sweden) were installed. After another 3 months of healing, abutment (Uni-abutment® 45; Astra Tech AB, Mo lndal, Sweden) connection was performed and a plaque control program was initiated. The animals were sacrificed and perfused with a fixative through the carotid arteries. Each implant site, including the implant and the soft and hard periimplant tissues, was dissected, decalcified in EDTA and further processed using a ''fracture technique''. The specimens were subsequently embedded in EPON, cut with the microtome set at 3 mm and the sections stained in PAS and toluidine blue. From the EPON-embedded blocks, ultra-thin sections were cut and electron micrographs were prepared. The detailed histologic and morphometrical examinations were restricted to a 200 μm wide zone of connective tissue interposed between the apical border of the junctional epithelium and the bone tissue. In the analysis, this zone was further subdivided into 2 different units; (i) one central, 40 μm wide unit (zone A) located immediately next to the implant surface, and (ii) one lateral, 160 μm wide unit (zone B) that was continuous with the central unit. The implant surface apical of the junctional epithelium and coronal of the bone crest appeared to be in direct contact with a connective tissue. Zone A of this connective tissue was characterized by its (i) absence of blood vessels and (ii) abundance of fibroblasts which were interposed between thin collagen fibers. The more lateral zone B contained comparatively fewer fibroblasts, but more collagen fibers and blood vessels. There are reasons to assume that the fibroblast rich tissue next to the titanium surface plays a rǒle in the maintenance of a proper seal between the oral environment and the peri-implant bone.

Notes: Abstract. The present experiment was performed to study the peri-implant tissue response to non-submerged (1-stage) and initially submerged (2-stage) implant installation procedures. 6 beagle dogs were used. All mandibular premolars and the 1st, 2nd and 3rd maxillary premolars were extracted. After 3 months of healing, 3 fixtures of the Astra Tech System were installed and submerged in the right (or the left) edentulous, premolar region in each of the 6 dogs. Radiographs were obtained immediately after fixture installation. In the radiographs, the distance between the abutment-fixture junction and the most ''coronal'' bone in contact with the implant surface was determined. 3 months later, abutments were connected to the initially submerged fixtures and another 3 fixtures of the same system were installed in the contralateral, edentulous premolar region. Abutments were, however, immediately connected to the newly-installed fixtures (nonsubmerged side; test side). The mucosal flaps were replaced, adjusted and sutured in such a way that the coronal portion of the abutments remained exposed in the oral cavity. A new set of radiographs were obtained from all 6 implant sites in each animal. A period of plaque control was initiated. Clinical examinations were performed and radiographs obtained from all implant sites after another 3 months and at the termination of the experiment. 9 months after the 1st fixture installation procedure, the animals were sacrificed, the mandibles were removed, and each implant region dissected. The most mesially-located implant sites were processed for ground sectioning. The remaining biopsies were processed and embedded in EPON. The histometric analysis included assessment of the vertical dimension of the marginal soft and mineralized peri-implant tissues. The ground sections were used for measurements describing (i) “bone to implant contact” and (ii) “bone density”. It was observed that the mucosa and bone tissue that formed at implants placed in a non-submerged or a submerged procedure had many features in common. Thus, figures describing (i) the height of the mucosa, (ii) the length of the junctional epithelium and the height and quality of the zone of “connective tissue integration”, (iii) the % of bone to implant contact as well as (iv) the density of the peri-implant bone, were similar in the submerged and the non submerged groups. It is therefore suggested that a non-submerged (1-stage) installation technique may provide conditions for tissue integration that are similar to those obtained using a submerged (2-stage) approach.

Notes: Abstract: Estrogen is known to play a critical role in both skeletal maturity and the rate of bone loss. This suggests the possibility that the estrogen receptor (ER) gene is one of the candidate genes that determines peak bone density and/or bone turnover rate. We investigated two established restriction fragment length polymorphisms (RFLPs) in intron 1 at the ER gene, represented as PvuII and XbaI. In 598 healthy Korean women aged 20–74 years, we examined the association of these ER genotypes with bone mineral density (BMD) and bone turnover status. The distribution of the PvuII and XbaI RFLPs was as follows: pp 205 (34.3%), Pp 308 (51.5%), PP 85 (14.2%) and xx 384 (64.2%), Xx 180 (30.1%), XX 34 (5.7%), respectively (where capital letters signify the absence of, and lower-case letters signify the presence of, the restriction site of each RFLP). No significant genotypic differences were found in BMD and bone markers. We grouped the subjects into three categories according to their menstrual status: 104 premenopausal women with regular menstruation, 182 perimenopausal women who had amenorrhea of not less than 3 months and not more than 12 months’ duration, and 312 postmenopausal women whose last menstruation was at least 12 months previously. No significant genotypic difference in either BMD or bone markers was found in any of these three groups. Furthermore we categorized women in peri- and postmenopause into a high loser group and a normal loser group according to the level of bone resorption markers. There was no difference in genotypic proportions between the high and normal loser groups. Our data suggest that these ER polymorphisms are not associated with BMD or bone turnover in Korean women.