Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Retention”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed2005

Comparison of two luting agents used for the retention of cast dowel and cores.

PURPOSE: The first purpose of this study was to compare the retentive values of zinc phosphate and Panavia F resin cements when used for luting cast dowel and cores. The second purpose was to determine whether the use of a lubricant when making the resin pattern for a custom dowel and core would have an effect on the final retention of dowels cemented with either zinc phosphate or Panavia F cements. METHODS AND MATERIALS: Sixty-three caries-free extracted single-rooted human teeth were randomly divided into three groups of 21. Root canal preparations were standardized for all 63 teeth. Clinical protocols for fabricating and cementing dowel and core restorations were examined, comparing zinc phosphate and Panavia F resin cements. Direct dowel patterns were fabricated using the Para Post system and cast in a noble metal alloy. Group I dowel spaces were lubricated with GC lubricant prior to dowel pattern fabrication and cleaned with Cavidry solvent before cementing the cast dowel and core with zinc phosphate cement. Group II dowel spaces were rinsed with water only prior to dowel pattern fabrication. The dowels and cores in this group were cemented with Panavia F resin cement. Group III dowel spaces were lubricated with GC lubricant prior to dowel pattern fabrication; the dowel spaces were cleaned with Cavidry solvent before the cast dowel and cores were cemented with Panavia F cement. The tensile force necessary to remove the cast dowel and cores was determined using a universal testing machine. Results were statistically analyzed using one-way ANOVA and Tukey's HSD test. RESULTS: The dowels and cores in Group I had significantly higher retentive values than either of the two Panavia F groups (p< or = 0.001). No difference in retentive values (p > 0.05) was found between dowels luted with either of the lubricating agents in the Panavia F groups. CONCLUSIONS: Zinc phosphate cement had higher retentive values when cementing cast dowel and cores than Panavia F. The type of lubricant used for the resin dowel fabrication (water or GC lubricant that was removed with a solvent) had no effect on the retention of cast dowels cemented with Panavia F.

Analysis of Variance↗
PubMedDate not supplied

Effect of core diameter and surface treatment on the retention of resin composite cores to prefabricated endodontic posts.

PURPOSE: With advances in adhesive dentistry and current emphasis on esthetic restorations, dowel systems have been developed to take advantage of these new techniques. Of interest when using these systems is the interaction between core materials and post materials. This investigation compared the tensile retentive force of two resin composite core materials to two metallic and one non-metallic prefabricated endodontic posts. Two dimensions of core build-up and two post-surface treatments were tested. MATERIALS AND METHODS: One hundred twenty posts (stainless steel, titanium alloy, and glass fiber-impregnated resin) were secured in a jig with 4 mm of the post extending into a cylindrical matrix. The matrix formed cylinders with diameters of 3 and 5 mm into which resin composite was inserted. The posts were treated or not treated with a bonding agent. After storage for 24 hours at 100% humidity, five specimens per condition were tested in an Instron testing machine at a crosshead speed of 0.5 mm/min. Failure loads were recorded in kilograms and failure modes were observed under light microscopy (40 x). Four-way analysis of variance and multiple comparison testing were used to compare means at the 0.05 level of significance. RESULTS: The means and standard deviations of tensile loads were calculated. All variables were significant in either main effects or interactions ( p<0.05). Fisher's PLSD intervals for post, core, treatment, and diameter were 2.0, 1.6, 1.6, and 1.6 kg, respectively. In most cases, the retentive force recorded for metallic posts was higher than that of glass fiber posts. Titanium posts had higher retentive forces than did the stainless steel posts. For metallic posts, 5-mm cores provided higher forces than 3-mm cores. In the glass fiber group, core diameter was not significant. For core materials, Build-It gave higher results with stainless steel posts, and FluoroCore gave higher results with the titanium ones. The surface treatment results were mixed. In the metallic post groups the adhesive failure data ranged between 80% and 100%, whereas in the glass fiber post groups, adhesive failures ranged between 60% and 70%. CONCLUSIONS: Within the limitations of this study, the metallic post groups always provided higher tensile retentive forces, with the titanium post groups showing higher retentive forces than the stainless steel ones. In the glass fiber post groups, different core diameters did not affect retention values.

Analysis of Variance↗
PubMed1984

Retention of emergency care knowledge.

This study provided data on the emergency care knowledge of students as measured by a pretest, posttest, and retention test. Fifty college students were the sample. The mean score for pretest was 62, posttest 86.75, and retention test 83.6. Pearson correlations were calculated for pretest, posttest, and retention test pairwisely. Data analyses revealed that all correlations were significantly greater than zero at the .05 level. A high relationship existed between students' posttest scores and retention test scores. ANOVA was used to gather information to determine if significant differences in students' first aid knowledge existed between the posttest and the retention test. Findings indicated that there was a significant difference between the emergency care knowledge scores of students when comparing the posttest to the retention test.

Analysis of Variance↗
PubMed1997

Effects of inactivating individual cerebellar nuclei on the performance and retention of an operantly conditioned forelimb movement.

These experiments were designed to examine the effects of inactivating separately each of the major cerebellar nuclear regions in cats on the execution and retention of a previously learned, operantly conditioned volitional forelimb movement. The experiments test the postulates that the cerebellar nuclei, and particularly the interposed nuclei, contribute substantially to the spatial and temporal features of the interjoint coordination required to execute the task and that the engram necessary for the retention of this task is not located in any one of the cerebellar nuclei. All cats were trained to perform a task in which they were required to reach for and grasp a vertical bar at the sound of a tone and move the bar to a reward zone through a template consisting of two straight grooves in the shape of an inverted "L." After the task was learned, the effects of inactivating separately each nuclear region (the fastigial, interposed, and dentate nuclei) using muscimol microinjections were determined. Data were analyzed by quantifying several features of the movement's kinematics and by determining changes in the organization of the reaching component of the movement using an application of dimensionality analysis, an analysis that examines the correlation among the changes in joint angles and limb segment positions during the task. The retention of the previously learned task also was assessed after each injection. Injections of each nuclear region affected temporal and spatial features of the learned movement. However, the largest effects resulted from inactivating the interposed nuclei. These effects included an increased length of the reach trajectory, an accentuated deviation of the wrist trajectory from a straight line, cyclic movement of the distal extremity as the target was approached, a difficulty in grasping the bar, altered temporal features of the movement, and a highly characteristic change in the dimensionality measurements. The changes in dimensionality reflected a decreased correlation (linear interdependence) of the joint angular velocities coupled with an increased correlation among the linear velocities of markers located on the joints themselves. Related but less consistent changes in dimensionality resulted from fastigial injections. The motor sequence required to negotiate the template could be executed after the nuclear microinjections, indicating that retention of the motor sequence was not affected by the inactivation of any of the cerebellar nuclei. However, in two of the five animals, some decreases in performance were observed after dentate injection that were not characteristic of changes related to an effect on retention. These data suggest that the cerebellum plays an important role in regulating the consistent, stereotypic organization of complex goal-directed movements, including the temporal correlation among joint angle velocities. The data also indicate that the retention of the task is not dependent on any of the individual cerebellar nuclear regions. Consequently, these structures are unlikely to be critical storage sites for the engram established during the learning of this task.

Adaptation, Physiological↗
PubMed2006

Effect of sildenafil (Viagra) on memory retention of a passive avoidance response in rats.

The effects of an intraperitoneal (i.p.) injection of different doses of sildenafil, a cyclic guanosin monophosphate (cGMP) specific phosphodiesterase type 5 (PDE 5) inhibitor, on memory retention of young (2-month-old) and middle aged (12-month-old) male Wistar rats were investigated. Passive avoidance behaviour was studied in a one trial learning, step--through type, passive avoidance task utilizing the natural preference of rats for a dark environment. In each category (young or middle-aged) different groups of rats received vehicle or sildenafil (1, 3, 10, 20 mg*kg(-1), i.p.) immediately after training and one group remained uninjected serwing as control. Retention latencies were measured 48 h later. To asses a possible non-specific proactive effect of sildenafil, the response latencies in a group of rats not receiving foot shock were also tested. The results showed that the post-training i.p. administration of sildenafil did not facilitate retention performance of a passive avoidance response in both young and middle aged rats compared to control or vehicle groups. Also, sildenafil did not affect response latencies in rats not having received the footshock on the training trial, indicating that sildenafil does not show a non-specific proactive affect on retention performance. The comparison of retention time between young and middle aged rats showed that the memory of the latter had been significantly reduced. In conclusion, this study suggests that sildenafil has no effects on memory retention in Wistar rats.

Age Factors↗
PubMed1989

[An experimental study on retentive force of a cone type denture retainer].

This study was made to clarify the retentive force of a denture retainer, i.e., a cone-type stud and sleeve attachment. In order to measure the wearing effect, an engaging and disengaging cycle test of 1,000 times was performed. The effects of taper angle (cone angle), sleeve height and thrusting force at engaging stud and sleeve on retentive force were also analyzed. 1. The cycle test had little effect on the retentive force (P not equal to 0.41). 2. The retentive force became greater with decrease of taper angle (P less than 0.0001). 3. The effect of the sleeve height on retentive force differed with taper angle (P less than 0.0001). 4. The retentive force became greater with increase of thrusting force (P = 0.0009), and this effect was greater as the taper angle decreased (P less than 0.0001). 5. The contributions of the factors were approximately 38% in taper angle, 30% in thrusting force and 2% in sleeve height. 6. It could be interpreted that we had better use the retainer with taper angle of 6 to 8 degrees, although the retainer with taper angle of 5 degrees could be applicable to the tooth on which the less occlusal force transmitted.

Denture Retention↗
PubMed1981

Short-term retention of temporal information.

The main purpose was to determine the short-term retention characteristics of temporal information when subjects experienced time under a conscious cognitive strategy for time estimation, i.e., subjects were instructed to refrain from employing the time-aiding techniques. Visual time lengths of 4, 8, 16, and 32 sec. were estimated by 12 subjects under the method of reproduction. Three levels of retention interval were used, viz., immediate reproduction, 20 sec. of rest, and 20 sec. of interpolated activity, i.e., counting backwards by threes. The variable error was used to evaluate effects of forgetting. When subjects hold time lengths of 4, 8, 16, and 32 sec. in memory for a period of 20 sec. of rest or 20 sec. of interpolated activity, they become more variable than if they recall the item immediately. The variability between the 20 sec. of rest and the 20 sec. of interpolated activity retention intervals was similar. Two explanations for the lack of an interaction between time lengths and retention interval under the variable error were suggested. The constant error was used as an index of bias. Immediate reproduction of the retention interval had less mean constant error than 20 sec. of rest retention under the 32-sec. time length. The particular result was explained in perceptual terms.

Adult↗
PubMed1982

Short-term retention of temporal auditory information.

To determine the short-term retention characteristics of temporal information when subjects experienced time under a conscious cognitive strategy for time estimation, i.e., subjects were instructed to refrain from employing time-aiding techniques, auditory durations of 1, 2, 4, 8, 16, and 32 sec. were estimated by 30 subjects by reproduction. Five levels of retention interval were used, viz., immediate reproduction, 30-sec. rest, 30-sec. interpolated activity with a response uncertainty of 0 bit per response, 30-sec. interpolated activity with a response uncertainty of 1 bit per response, and 30-sec. interpolated activity with a response uncertainty of 2 bits per response. Variable error evaluated effects of forgetting. When subjects hold durations of 8, 16, and 32 sec. in memory for a 30-sec. rest or 30-sec. interpolated activity, they become more variable than if they recall the item immediately. The variabilities between the 30-sec. rest and the 30-sec. interpolated activity retention intervals were similar. Two explanations for the presence of an interaction between duration and retention interval under the variable error were suggested. The constant error was used as an index of bias. Immediate reproduction of the retention interval had less mean constant error than 30-sec. rest retention under the 8-, 16-, and 32-sec. durations. That particular result was explained in perceptual terms.

Adult↗
PubMed2006

Study of the colors and retention of over-the-counter cosmetic veneers.

The purpose of this study was to observe the tooth colors and retention of a cosmetic veneer Fiche Pearl On containing shellac and five experimental formulations containing benzoin gum and ethyl cellulose. Tooth color was measured with a spectrophotometer before and after application of the veneers to the buccal or labial surface of experimental teeth. Through both in vitro and in vivo studies, the retention rates of veneers were assessed. In terms of color difference (deltaE*ab) between before and after veneer application, it ranged from 4.3 (Fiche Pearl On) to 15.0 (experimental formulation White Plus). In terms of retention rate, in vitro test found the retention rate of experimental formulation White Plus was significantly higher than that of Fiche Pearl On. In in vivo test where subjects were permitted to drink water and tea, it was found that the retention rate after two hours ranged from 94.0 to 98.5%. In conclusion, teeth applied with the experimental cosmetic veneer formulations showed better color and retention than teeth with Fiche.

Analysis of Variance↗
PubMed1999

Effects of oxytocin and an oxytocin receptor antagonist on retention of a nose-poke habituation response in mice.

The present study describes the use of nose-poke habituation as a memory task in mice and demonstrates that it is sensitive to oxytocin (OT) and an oxytocin receptor antagonist (AOT) administered after the learning trial. Habituation of nose-poke behavior of mice was defined as a reduction in number of nose-pokes compared to baseline, and was measured in a hole-board apparatus to which male Swiss mice were exposed on two consecutive days for 5 min, respectively. Immediate post-training subcutaneous administration of OT (2.00 micrograms/kg) impaired retention performance, whereas AOT (0.20 microgram/kg) enhanced it. Neither the impairing effects of OT (2.00 micrograms/kg) nor the enhancing effects of AOT (0.20 microgram/kg) were seen when the training treatment interval was 180 min, suggesting that both treatments influenced the storage of recently acquired information. The effects of OT (2.00 micrograms/kg) on retention were prevented by AOT (0.02 microgram/kg) administered immediately after training but 10 min prior OT treatment. This dose of antagonist did not affect retention by itself which suggest that impairing effects of OT on retention are probably due to an interaction of the neuropeptide with specific receptors. The actions of OT and AOT on retention were not due to enduring proactive effects of the compounds on performance during the retention test, since when given to untrained mice did not modify their spontaneous activities in the hole-board when recorded 24 h later. We suggest that nose-poke habituation learning can be a suitable method to investigate the mnestic effects of drugs, and that oxytocin negatively modulates memory storage of this form of learning elicited by stimuli repeatedly presented without reinforcement.

Animals↗
PubMed2000

Retention of a core material supported by three post head designs.

STATEMENT OF PROBLEM: There are few studies on the retention of core build-up materials to prefabricated post head designs, especially for a new ceramic post design. PURPOSE: This in vitro study compared the retention of 2 types of core build-up materials (Ti-Core titanium-reinforced composite and a GC Miracle Mix silver-reinforced glass ionomer) supported by 3 post head designs (Flexi-Post, AccessPost, and Cerapost dowel). For all test groups, heads of the posts were placed into the core material at a 90-degree angle to the surface. Test specimens (unloaded) were then placed into a special jig and retention test was performed using an 810 MTS testing machine. MATERIAL AND METHODS: This study consisted of 6 groups with 10 specimens per group. A 3 x 2 factorial design was used to test for statistical significance and results were considered significant when P <.05. RESULTS: Results of the retention test were as follows: group 1, Flexi-Post/Ti-Core 220.0 lb (982.1 N), group 2, AccessPost/Ti-Core 212.7 lb (949.6 N), group 3, Cerapost/Ti-Core 41. 8 lb (186.6 N), group 4, Flexi-Post/Miracle Mix 43.4 lb (193.8 N), group 5, AccessPost/Miracle Mix 61.6 lb (275 N), and group 6, Cerapost/Miracle Mix 7.5 lb (33.5 N). Results of the ANOVA revealed a highly significant difference between posts and cores (P <.0001). CONCLUSION: Post head designs of the stainless steel AccessPost and Flexi-Post dowels offers greater retention then the smooth ceramic head design of the Cerapost dowel. In addition, the composite core material (Ti-Core) offers greater retentive strength values than the glass ionomer material (Miracle Mix).

Analysis of Variance↗
PubMed2001

Acute urinary retention in children.

PURPOSE: Acute urinary retention is relatively infrequent in children. There are a variety of causes that are poorly defined in the literature, and they differ greatly from those seen most frequently in adults. We review our experience with pediatric patients presenting with urinary retention to 2 major metropolitan children's hospitals. MATERIALS AND METHODS: Records from Egleston and Scottish Rite Hospitals for Children were reviewed for a 6-year period for the diagnosis of urinary retention. Urinary retention was defined as inability to empty the bladder volitionally for greater than 12 hours with a volume of urine greater than expected for age ([age in years + 2] x 30 cc) or a palpably distended bladder. All cases resulting postoperatively and believed secondary to surgical dissection, narcotic use or immobility, and children previously diagnosed with chronic neurological disorders and voiding dysfunction or with reduced mental status were excluded from study. The majority of these encounters were emergency department visits specifically for acute urinary retention. RESULTS: We identified 53 children meeting these criteria, including 37 boys 6 months to 17 years old and 16 girls 1 to 17 years old. Etiologies included neurological processes in 17%, severe voiding dysfunction in 15%, urinary tract infection in 13%, constipation in 13%, adverse drug effect in 13%, local inflammatory causes in 7%, locally invading neoplasms in 6%, benign obstructing lesions in 6%, idiopathic in 6%, combined urinary tract infection and constipation in 2%, and incarcerated inguinal hernia in 2% of cases. Adverse drug effects and dysfunctional voiding were implicated 3 times as often in males than females (16% versus 6% and 19% versus 6%, respectively). Urinary tract infections were 6 times more common in females (31% versus 5%). Constipation and local inflammatory processes were twice as common in females than males (19% versus 11% and 12% versus 5%, respectively). Local neoplasms, benign obstruction and idiopathic causes were found exclusively in males. CONCLUSIONS: Urinary retention in children is a relatively rare entity but there is a significant incidence of neurological abnormalities in this population. If a clear reason for this condition cannot be delineated based on history, physical examination and laboratory assessment, these patients should undergo prompt neurological evaluation and appropriate imaging studies.

Acute Disease↗
PubMed2001

[Delirium due to urinary retention: confusing for both the patient and the doctor].

A delirium due to urinary retention confuses both patient and physician. Three patients presented with delirium and/or physical deterioration had a bladder retention. A man aged 82 had delirium and an acute renal failure due to a urinary retention with an enlarged prostate gland. A woman aged 81 had a delirium and a bladder retention due to an atonic bladder. A man aged 71 showed cognitive deterioration and a bladder retention due to a backbone-fracture and faecal impaction. In the elderly it is very important to include urinary retention in differential diagnosis because its presentation can be atypical.

Aged↗
PubMed2001

Urinary retention in hospitalised older women.

INTRODUCTION: Information about urinary retention in women is scarce. We conducted a case-control study to identify the symptoms and risk factors associated with urinary retention in hospitalised older women. MATERIALS AND METHODS: Targeted history (especially lower urinary tract symptoms) and physical examination of 60 women (65 years or older) who had post-void residual urine volume (PRUV) (determined using a portable ultrasound Bladder Scan BVI-2500) of more than 100 mL were studied and compared with 60 controls. RESULTS: Symptoms of voiding difficulties had low positive predictive value (PPV) and negative predictive value (NPV), except for poor stream, which has a PPV of 100%. Only one-third of the patients with high PRUV had a palpable bladder. Associated with high PRUV were: 1) constipation [odds ratio (OR), 4.12; 95% confidence interval (CI), 1.90-8.91; P = 0.0004]; 2) urinary tract infection (UTI) (OR, 3.36; 95% CI, 1.58-7.12; P = 0.002); 3) impaired mobility (OR, 2.37; 95% CI, 1.12-4.97; P = 0.02); 4) past history of UTI (OR, 3.5; 95% CI, 1.34-9.14; P = 0.014); 5) past history of urinary retention (OR, 6.33; 95% CI, 1.72-23.33; P = 0.004); 6) stroke (OR, 2.5; 95% CI, 1.24-5.41; P = 0.017); 7) diabetes mellitus with microvascular complications (OR, 2.76; 95% CI, 1.08-7.04; P = 0.042). Applying logistic regression analysis, the three best predictive variables for high PRUV were constipation, UTI and past history of urinary retention. CONCLUSION: Symptoms (except for positive history of poor stream) and signs were unreliable in diagnosing urinary retention in hospitalised older women. Patients with the above risk factors should have their PRUV ascertained, which can be done reliably non-invasively. Early detection with appropriate intervention can potentially prevent the morbidity and mortality associated with urinary retention.

Aged↗
PubMed2002

Critical evaluation of the problem of chronic urinary retention after orthotopic bladder substitution in women.

PURPOSE: We studied the possible causes of chronic retention after radical cystectomy and orthotopic bladder substitution in women. MATERIALS AND METHODS: Between January 1995 and January 2001, 136 women with a mean age plus or minus standard deviation of 52 +/- 8 years underwent standard radical cystectomy and orthotopic substitution for organ confined bladder cancer. Videourodynamics, pelvic floor electromyography, pelvic floor magnetic resonance imaging and pan-endoscopy were done. In the last 37 cases some technical modifications were adopted to circumvent the development of chronic urinary retention. RESULTS: One woman died postoperatively of massive pulmonary embolism. Of the 100 patients evaluable at a mean followup of 36 months 95 were continent in the daytime, 86 were continent at night, 2 were completely incontinent and 16 were in chronic retention. Videourodynamics showed that retention was mechanical in nature due to the pouch falling back in the wide pelvic cavity, resulting in acute angulation of the posterior pouch-urethral junction. In addition, herniation of the pouch wall through the prolapsed vaginal stump was observed in most cases. Pelvic floor electromyography demonstrated complete pelvic floor silence during voiding. No abnormality of the pelvic floor or rhabdosphincter was noted on magnetic resonance imaging. Pan-endoscopy showed a normal urethra with no urethroileal stricture. A 4 mg. dose of the alpha1-adrenergic blocker doxazosin daily was ineffective, excluding the possibility that sprouting from adjacent adrenergic neurons into the denervated proximal urethral muscles may have been the cause of this problem. After omental packing behind the pouch, suturing of the peritoneum on the rectal wall to the vaginal stump, suspension of the latter by the preserved round ligaments and suspension of the pouch near its dome to the back of the rectus muscle at cystectomy the incidence of chronic retention decreased from 18.7% (14 of 75 cases) before to 8% (2 of 25) after modifications. Furthermore, after vaginal wall descent was mechanically corrected by a pessary there was significant improvement in evacuation. CONCLUSIONS: Strong evidence was provided that chronic urinary retention after orthotopic substitution is due to anatomical rather than to functional or neurogenic reasons. Modifications to increase back support of the pouch with ventral suspension near its dome and support the vaginal stump are recommended to avoid this complication.

Chronic Disease↗
PubMed2002

Retention strengths of five luting cements on prefabricated dowels after root canal obturation with a zinc oxide/eugenol sealer: 1. Dowel space preparation/cementation at one week after obturation.

PURPOSE: This investigation examined the effect of 5 different cements on the retention strength of prefabricated endodontic dowels placed into root canals previously obturated with gutta percha and a zinc oxide/eugenol (ZOE) sealer. MATERIALS AND METHODS: Ninety-six single-rooted teeth were decoronated, filed, cleaned, sequentially shaped, and divided into 6 groups of 16 specimens each. Five of the groups were then obturated with gutta percha and a ZOE sealer. One group was not obturated and served as the control group. Dowel space preparation and dowel cementation for all groups were completed 1 week later. Ten-mm deep dowel spaces were prepared using size 6 Gates Glidden drills. Size 5 Paraposts were then cemented with 5 different cements: Panavia 21 for group 1 (unobturated controls) and group 2; Ketac-Cem glass ionomer for group 3; Fleck's zinc phosphate for group 4; Parapost (composite) Cement for group 5; and C&B Metabond 4-META for group 6. After 48 hours, the dowels were removed using a universal testing machine in tensile mode at 1 mm min(-1). RESULTS: The following results were found (all values in kg): group 1 (controls; Panavia 21) mean = 61.81, 95% CI = +/-8.65; group 2 (Panavia 21), mean=43.15, 95% CI = +/-7.81; group 3 (Ketac-Cem), mean =34.45, 95% CI = +/-4.93; group 4 (zinc phosphate), mean = 25.07, 95% CI = +/-5.03; group 5 (Parapost Cement), mean = 24.99, 95% CI = +/-5.35. None of the group 6 (C&B Metabond) specimens developed measurable bond strengths, so this group was excluded from parametric statistical analyses. An analysis of variance (ANOVA) showed a significant effect of group; pairwise multiple comparison procedures (Tukey test) showed that group 1 (controls) had significantly greater retention than all other groups (p <0.001); group 2 (Panavia 21) had significantly greater retention than groups 4 (zinc phosphate) and 5 (Parapost cement) (p <0.001). None of the other pairwise comparisons were statistically different. CONCLUSION: Paraposts cemented with Panavia 21 in unobturated root canals exhibited significantly higher retention than Paraposts luted with Panavia 21 and 4 different cements into dowel spaces prepared 1 week after obturation with gutta percha/ZOE sealer (p <0.001). Among the obturated groups, Panavia 21 cement (group 2) demonstrated significantly greater retention of Paraposts than zinc phosphate (group 4) and Parapost composite (group 5) cements (p <0.001). Ketac-Cem glass ionomer cement (group 3) had intermediate retention values that were not statistically different than those of groups 2, 4, and 5 (p >0.05). The 4-META cement, C&B Metabond, failed to polymerize.

Analysis of Variance↗
PubMedDate not supplied

Retention, marginal leakage, and cement solubility of provisional crowns cemented with temporary cement containing stannous fluoride.

PURPOSE: This in vitro study investigated the (1) retention and microleakage of provisional crowns cemented with temporary cements to which stannous fluoride (SnF2) was added, and (2) solubility of these cements. MATERIALS AND METHODS: Provisional crowns were constructed of acrylic resin with shoulder preparations for 12 molars. The crowns were luted with Tempbond, Tempbond NE, and Freegenol temporary cements, and also with SnF2 added to these cements. Specimens were thermocycled 100 times, stored for 6 days, and immersed in 0.5% basic fuschin. Seven days after cementation, crown removal (retention) tests were conducted. Marginal leakage was assessed using a five-level scale to score dye penetration. Solubility in water of the cements with and without SnF2 was assessed using cement disks. RESULTS: Freegenol was more retentive than the other cements. The incorporation of SnF2 significantly increased the retention capacity of Freegenol and Tempbond NE but had no effect on Tempbond. Tempbond showed significantly higher dye penetration than Freegenol. The addition of SnF2 did not alter the dye penetration of the cements. There were no significant differences in the solubility of the cements. However, the incorporation of SnF2 increased the solubility of Freegenol and Tempbond NE (P < .001) and Tempbond (P < .01). CONCLUSION: The addition of SnF2 increased the retention of temporary crowns cemented with Tempbond NE and Freegenol but did not affect the retention of those cemented with Tempbond. The marginal leakage of crowns cemented with the tested temporary cements with and without the incorporation of SnF2 was similar. However, the addition of SnF2 increased the solubility of the cements.

Acrylic Resins↗
PubMed2003

Prostate-specific antigen and transition zone index - powerful predictors for acute urinary retention in men with benign prostatic hyperplasia.

OBJECTIVES: To examine the efficacy of prostate-specific antigen and various parameters obtained by transrectal ultrasonography as predictors of acute urinary retention in patients with benign prostatic hyperplasia. METHODS: Eighty-nine men with symptoms of benign prostatic hyperplasia were enrolled in this study from February 2002 to June 2003. Among them, 21 patients presented with acute urinary retention. Transrectal ultrasonography was used to calculate the total prostate volume, transition zone volume and transition zone index. Sample of prostate-specific antigen was taken in outpatient clinic or in clinic before first insertion of the catheter into the bladder, because of urinary retention. If the patient presented with inserted catheter, we used latest prostate-specific antigen date from the medical notes of outpatient clinic. To compare the usefulness of the various indexes, the area under the receiver-operator characteristic curve was calculated for each index. RESULTS: There were significant differences between patients with and without acute urinary retention in the total prostate volume (58.16 cm(3) and 44.28 cm(3), p=0.0028), transition zone volume (36.62 cm(3) and 23.70 cm(3), p=0.0001), transition zone index (0.62 and 0.51, p=0.00022), prostate-specific antigen (4.96 ng/ml and 2.97 ng/ml, p=0.00069), age and quality of life score, but no significant difference in International Prostate Symptom Score. In patients with acute urinary retention, the area under the receiver-operator characteristic curve was 0.775 for transition zone index, 0.742 for prostate-specific antigen, 0.737 for transition zone volume, 0.696 for total prostate zone volume and 0.633 for International Prostate Symptom Score. CONCLUSIONS: The transition zone index and prostate-specific antigen are accurate predictors of acute urinary retention in patients with benign prostatic hyperplasia and may be useful for deciding between surgical intervention and medical treatment.

Acute Disease↗