Clinical retrospective study of dental implant removal: do patients who require implant removal desire implant prosthesis again?

Background

This study investigated the causes of dental implant removal due to complications, and examined whether patients who had dental implant removal desired re-implant prosthesis treatments.

Material and Methods

A retrospective case–control study was conducted on patients who had their dental implants removed. We investigated whether the removed dental implant was replaced with other implant prostheses. Age, sex, diabetes, smoking, implant site distribution, reason for implant removal, and blade and root-form implants were categorized as predictive variables. The outcome variable was desire for re-implantation or use of other prosthetic methods after implant removal. A logistic regression model was created to identify patient factors that could predict the re-implantation of dental prostheses after implant removal.

Results

A total of 215 dental implants were removed from 143 patients. The most common reason for implant removal was peri-implantitis that was identified in 165 implants. After implant removal, re-implantation was performed in 98 implants (45.6%). Bivariate analyses showed that age, diabetes, implant type, and reason for implant removal were associated with the desire for re-implanted prostheses. The multiple regression model revealed that age, implant type, and reason for implant removal were associated with an increased desire for re-implant prostheses after implant removal.

Conclusions

Re-implantation of prostheses after the removal of dental implants was desired by patients who were younger, had implants placed in the root form, and had implants removed due to prosthetic-related complications.

Key words:Dental implant removal, complications, implant prosthesis, retrospective study, re-implantation.

Beliefs of chronically ill Japanese patients that lead to intentional non-adherence to medication

OBJECTIVE

To identify factors, associated with personal beliefs, involved in intentional non-adherence to prescribed medication of Japanese patients with chronic diseases.

METHODS

A cross-sectional study of Japanese subjects with chronic, primarily liver, gastrointestinal, or nervous system diseases who had been prescribed oral medicines for regular use, was performed. The subjects were admitted to a university hospital and were interviewed face-to-face on admission. Intentional non-adherence was defined as experience of deliberate adjustment of self-managed prescription medicines during the few months prior to hospital admission. Patients' beliefs about taking medicines were assessed from the perspective of what the patient valued in order to take medicines without anxiety; whether the patient valued information about the medication such as its function and side-effects and/or mutual reliance on doctors. Using logistic multivariate regression analyses, factors associated with intentional non-adherence were identified.

RESULTS

Among 154 subjects, 51 showed intentional non-adherence. Intentional non-adherence was associated with the following three factors: (a) the patients' beliefs with respect to taking medicines without anxiety, especially putting no value on mutual reliance on the patient-doctor relationship (P < 0.001) and putting great value on knowing the drug's side-effects (P < 0.001), (b) poor comprehension of general aspects of medication (P for trend < 0.001), and (c) being in the prime of life (40-59 years) (P = 0.011). Comprehension of the function of each medicine, experience of side-effects, anxiety about taking medicines, and the number of types of medicines taken, were not associated with non-adherence.

CONCLUSIONS

Beliefs on which individual Japanese patients with chronic diseases attach value in order to take medicines without anxiety were potential factors for intentional non-adherence. This emphasizes the necessity of a patient-oriented approach to take account of patients' personal beliefs about medicines to increase adherence rate in Japan.

[Analysis of factors influencing the self-regulation of medication and construction of an educational program for patients with chronic hepatic diseases]

The purpose of this study is to construct an educational program for patients with chronic hepatic diseases to avoid self-regulation of medication. We have statistically analyzed the influencing factors of self-regulation from the following 3 viewpoints. First, in the investigation of the number of and the kind of prescribed medicines, it was found that the number of prescribed medicines increased sharply at the stage of Liver Cirrhosis b. Secondly, in the survey of patients' awareness of medication, it was found that self-regulation was influenced by lack of understanding the effects of medicines and the necessity of medication, and by lack of understanding the clinical conditions. Especially, at the stage of Liver Cirrhosis b, self-regulation was strongly influenced by lack of understanding the clinical conditions. Lastly, in the evaluation of patients' characteristics by pharmacists, self-regulation was also strongly influenced by the level of understanding the necessity of medication, understanding the clinical conditions, a patient-doctor relationship, and anxiety about side-effects of medicines. Therefore we have constructed an educational program for patients from the viewpoint of medication. The information consists of two articles; one is the action mechanism of the medicine connected with the clinical conditions to help the patients understand the necessity of medication; the other is how to check the effect and adverse reaction of the medication by themselves to decrease the anxiety about side-effects. Consequently, the medication management and the consultation for inpatients with chronic hepatic diseases were standardized by incorporating the education with the information described above.

Administration of thymocytes derived from non-pregnant mice induces an endometrial receptive stage and leukaemia inhibitory factor expression in the uterus

We have previously reported that intravenous administration of splenocytes prepared from mice in the early stages of pregnancy promoted embryo implantation in pseudopregnant mice. Since a T-lymphocyte-rich, but not a monocyte-rich preparation from splenocytes enhanced embryo implantation, similar effects of thymocytes from non-pregnant mice on implantation were examined in this study. Thymocytes were prepared from immature 21 day old ICR female mice and the supernatant of a thymocyte suspension (Th-sup) was used as the control. Thymocytes or Th-sup were injected into the caudal vein of recipient mice on pseudopregnancy day 2, and blastocysts were transferred into the endometrial lumen. The implantation rates per recipient were significantly higher in the thymocyte-treated group. ICR mice were then oophorectomized on pseudopregnancy day 3. After 3-day progesterone supplementation, blastocysts were transferred with intravenous injection of thymocytes or Th-sup. Under progesterone supplementation, successful implantations were observed in the thymocyte-treated group, but not in the Th-sup-treated group. Reverse transcriptase-polymerase chain reaction analysis revealed that mRNA expression of leukaemia inhibitory factor in the uterus was induced by thymocyte administration, but not by Th-sup. Thymocytes were divided into two populations, CD4(+/-)CD8(-) group and CD4(-)CD8(+/-) group, by separation columns. On pseudopregnancy day 2, the separated thymocytes in each group or their supernatant were injected into the endometrial stroma of the recipient mice, and blastocysts were transferred into the endometrial lumen. The administration of CD4(+/-) CD8(-) lymphocytes significantly promoted implantation rates, but no effect was observed in the CD4(-) CD8(+/-) group. These findings showed that thymocytes, especially CD4-positive lymphocytes, facilitate embryo implantation, probably by regulating endometrial differentiation.

Splenocytes in early pregnancy promote embryo implantation by regulating endometrial differentiation in mice

We have reported that i.v. administration of splenocytes prepared from early pregnant mice promoted embryo implantation in pseudopregnant CD-1 (ICR) (closed colony) mice. In this study, the similar effects of splenocytes were confirmed using an inbred strain, BALB/c mice, and the mechanism was further investigated. Splenocytes were prepared from pregnancy day 4 (P4-spl) and dioestrus mice (Di-spl), and supernatant of P4-spl suspension (P4-sup) was used as controls. On pseudopregnancy day 2, splenocytes or supernatant were injected into caudal vein or endometrial stroma of the recipient mice, and blastocysts were transferred into the endometrial lumen. In both BALB/c and ICR strains, the implantation rates per recipient with i.v. and intraendometrial injection were significantly higher in P4-spl groups. Then, ICR mice were oophorectomized on pseudopregnancy day 3. After 3 day progesterone supplementation, blastocysts were transferred with i.v. injection of P4-spl and P4-sup, or s.c. oestradiol injection. Under progesterone supplementation, successful implantations were observed in the P4-spl- and oestradiol-treated groups, but not in P4-sup-treated group. Reverse transcriptase-polymerase chain reaction analysis revealed that messenger RNA expression of leukaemia inhibitory factor in the uterus was induced by P4-spl and oestradiol, but not by P4-sup. These findings showed that splenocytes of early pregnant mice promote embryo implantation by regulating endometrial differentiation.

Intravenous administration of splenocytes in early pregnancy changes the implantation window in mice

To clarify the role of immune cells in the reproductive phenomenon during early pregnancy, we investigated the effect of splenocytes obtained from mice in early pregnancy on embryo implantation. We prepared splenocytes from 5 week old pregnant ICR mice on day 4 (pregnancy day 4 splenocytes; P4-spl) and day 8 (pregnancy day 8 splenocytes; P8-spl), from 5 week old pseudopregnant ICR mice on day 4 (pseudopregnancy day 4 splenocytes; PP4-spl) and from 5 week old di-oestrous virgin mice (di-oestrous splenocytes; Di-spl). The supernatants (P4-sup, P8-sup, PP4-sup and Di-sup) derived from the suspensions of P4-spl, P8-spl, PP4-spl and Di-spl respectively, were used in the control groups. The recipient pseudopregnant mice (6 weeks of age) were injected i.v. with splenocytes (2 x 10(7) cells) or supernatants as controls, and embryo transfer was performed on day 2. Embryo implantation was evaluated 7 days later under laparotomy. The successful implantation rate per embryo was markedly higher compared with the control groups in the P4-spl (30.5 +/- 8.55 versus 1.0 +/- 1.37%, n = 200, P < 0.01) and P8-spl (20.1 +/- 10.3 versus 1.17 +/- 1.62%, n = 200, P < 0.05) groups. On the other hand, a slight but not significant increase was observed in the PP4-spl (8.33 +/- 8.80% versus 1.5 +/- 1.37%, n = 200) and Di-spl (9.0 +/- 5.76% versus 2.3 +/- 2.28%, n = 200) groups. Among the splenocyte administration groups, the implantation rate in the P4-spl group was significantly higher than in the PP4-spl and Di-spl groups (P < 0.01). These findings indicate that i.v. administration of splenocytes can change the murine implantation window. Since the splenocytes during early pregnancy are most effective on embryo implantation, peripheral immune cells in early pregnancy may be involved in embryo implantation.

The use of intra-endometrial embryo transfer for increasing the pregnancy rate

It has been demonstrated previously that pregnancy can be achieved by the direct insertion of embryos into the endometrial stroma (intra-endometrial embryo transfer) of mice. In this study we evaluated whether intra-endometrial transfer resulted in a higher pregnancy rate than conventional embryo transfer. Mouse blastocysts (ICR strain), recovered on day 4 of pregnancy, were transferred into pseudopregnant day 2, day 3 and day 4 mice of the same strain; 1-, 2- and 8-cell embryos were also transferred into pseudopregnant day 4 mice. In intra-endometrial embryo transfer, a 27 gauge injection needle was inserted near the utero-tubal junction into the endometrial stroma and then removed; one blastocyst was transferred into each uterine horn with a glass micropipette. Conventional transfers were performed simultaneously as controls. The pregnancy rates and embryonic viability rates were evaluated 9 days after embryo transfer. Furthermore, the rates of live birth for intra-endometrial and conventional embryo transfers were compared when blastocysts were transferred into pseudopregnant day 4 uteri by both methods. In the transfer to pseudopregnant day 2 recipients, the pregnancy and embryonic viability rates were significantly higher (P < 0.01) in intra-endometrial [23.4 (11/47) versus 15.9% (15/94)] than in conventional embryo transfer [4.3 (2/46) versus 2.2% (2/92)]. In the transfer to pseudopregnant day 3 recipients, both rates were also higher (P < 0.01) in intra-endometrial [90.9 (40/44) versus 87.5% (77/88)] than in conventional transfer [67.4 (31/46) versus 64.1% (59/92)].(ABSTRACT TRUNCATED AT 250 WORDS)

Developmental potential of frozen-thawed human blastocysts

PURPOSE

To examine the possibility of freezing human embryos at late cleaved stages (morula or blastocyst stage), we cryopreserved human embryos 5 days (day 5) or 6 days (day 6) after insemination and investigated their developmental potential after thawing.

MATERIALS AND METHODS

One hundred nineteen morphologically good-quality human embryos from 43 women undergoing in vitro fertilization treatment between 1991 and 1992 were frozen using dimethylsulfoxide as a cryoprotectant. The embryos were cryopreserved for 5 to 30 months. After thawing they were then cultured in vitro for 24 hr to investigate their developmental potential. Survival rates and developmental rates were morphologically assessed after 24 hr of in vitro culture.

RESULTS

Developmental rates were significantly (P < 0.01 or P < 0.05) lower than survival rates at every developmental stage. There was no difference in total survival rates between embryos frozen 5 days after insemination (78.2%; 54/69) and embryos frozen 6 days after insemination (70.0%; 35/54). However, the developmental rates after 24 hr of culture was significantly (P < 0.05) lower for embryos frozen 6 days after insemination (6.0%; 3/50) than for embryos frozen 5 days after insemination (18.8%; 13/69). Only two embryos developed into fetuses after transfer into the uterus (1.7%; 2/119).

CONCLUSIONS

From the results, the developmental potential of frozen-thawed human blastocysts was found to be significantly reduced, even though the blastocysts were of morphologically good quality. Longer in vitro exposure of embryos appears to reduce their developmental potential.

Relationship between the day of embryo transfer and the outcome in human in vitro fertilization and embryo transfer

PURPOSE

To clarify the optimal date of embryo transfer (ET), we retrospectively analyzed the relationship between the day of ET and the outcome in human in vitro fertilization and embryo transfer (IVF-ET).

METHOD

Of a total of 307 human IVF-ET cycles performed at Kyoto University Hospital between January 1990 and March 1994, we focused on 207 cases of IVF-ET cycles in which two or three good-quality embryos were transferred. These 207 IVF-ET cycles consisted of 54 Day 2 ET cycles, 79 Day 3 ET cycles, 46 Day 4 ET cycles, and 28 Day 5 ET cycles. We compared the pregnancy and live-birth (plus ongoing pregnancy) rates among these four ET groups.

RESULTS

The pregnancy rates of ET on Days 2 to 4 were not significantly different, whereas Day 5 ET produced a significantly lower pregnancy rate (Day 2, 29.6%; Day 3, 32.9%; Day 4, 30.4%; Day 5, 10.7%). Similar results were obtained for the live-birth (plus ongoing pregnancy) rates (Day 2, 20.3%; Day 3, 18.9%; Day 4, 17.9%; Day 5, 7.1%).

CONCLUSIONS

These results suggest that the day of ET does not fundamentally affect the pregnancy rate in human IVF-ET provided that transfer is made before Day 5.

Morphology of the synovium during its differentiation and development in the mouse knee joint. A histochemical, SEM and TEM study

The prenatal and postnatal development of the mouse knee joint was investigated by transmission and scanning electron microscopy. In the prenatal stage, following the appearance of a narrow intercellular cleft between two skeletal elements on the 16th fetal day, clefting extended into the lateral synovial mesenchyme. In some regions, the extension of the cleft was very rapid, but in a certain region (future fat pad region), it was somewhat slower. Macrophage-like cells appeared in the synovial mesenchyme on the 16th fetal day, and then increased in number, and were distributed as if they were clustering around the presumptive clefting zone in the future fat pad region on the 17th-18th fetal day. This suggests that macrophage-like cells may participate in joint development, as they phagocytize and remove some kinds of solid extracellular matrix, and facilitate the cleft extension. In the early postnatal stage, scanning electron microscopic observations showed that there were two different types of cell in the synovial lining. One of them exhibited a surface morphology corresponding to that of macrophages: a spherical cell body and numerous pseudopodia. The other type of cell exhibited various cell shapes with many cytoplasmic processes extending along the synovial surface.