instruction:
Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
question:
Context: The aim of the current study was to test the impact of dentin powder on the antimicrobial efficacy of bioactive glass S53P4 (BAG).', 'BAG was suspended (preincubated) in saline at 37 degrees C for different time periods with or without human dentin powder, hydroxylapatite, or decalcified dentin. Subsequently, Enterococcus faecalis ATCC 29212 cells were added to these suspensions and bacterial recovery measured with and without the use of gentle sonication. Furthermore, survival of bacteria in test and control suspensions was assessed over time. Supernatants of suspensions were analyzed for their element contents using atomic absorption spectrophotometry. The effects of pH, silica, and osmolarity on E faecalis viability were assessed using specifically prepared solutions.', 'BAG preincubated with dentin powder caused a significant (P < .05) decrease in viability compared to pure BAG suspensions. This was not based on adherence of bacteria to solid particles or agglutination of the cells, because sonication did not increase bacterial yields. Hydroxylapatite and decalcified dentin did not increase BAG killing efficacy. The additive effect of BAG + dentin powder was dose dependent, occurred only with solids in suspension, and increased with suspension time. An augmented dissolution of glass components, especially silicon, was measured in BAG + dentin powder compared to pure BAG suspensions or counterparts containing hydroxylapatite or decalcified dentin. High osmolarity per se did not affect E faecalis viability, whereas high pH and silica levels did.
Answer: The observed phenomenon was related to an increased BAG dissolution triggered by dentin powder, causing elevated local pH and silica levels.
answer:
Does dentin enhance the effectiveness of bioactive glass S53P4 against a strain of Enterococcus faecalis?


question:
Context: The failure of in utero transplantation in immune-competent recipients suggests the existence of a fetal immune barrier. The importance of donor major histocompatibility complex (MHC) class I expression in the induction of prenatal tolerance remains undefined. We hypothesized that donor cell MHC class I expression facilitates engraftment in prenatal allogeneic recipients rather than promoting immune rejection.', 'B6.Ly5.2 (class I(+)) or B6.TAP(-/-) (class I(-)) murine fetal liver cells were transplanted into age-matched allogeneic fetal recipients. Survival to weaning and subsequent growth was assessed. Engraftment rates and peripheral blood chimerism levels were measured serially.', 'The presence or absence of class I expression did not affect survival or growth of recipients and no graft-vs-host disease developed. Allogeneic recipients of B6.Ly5.2 cells exhibited significantly higher levels of donor hematopoietic chimerism when compared to recipients of B6.TAP(-/-) cells (27% + 10% vs 11% + 8%; P = .004) that deteriorated further over time.
Answer: Donor class I MHC antigen expression is essential for stable long-term engraftment and maintenance of donor-specific tolerance. Further studies are needed to better characterize the role of the fetal innate immune system in prenatal allotransplantation.
answer:
Does donor major histocompatibility complex class I expression determine the outcome of prenatal transplantation?


question:
Context: AIM, MATERIAL AND METHODS: Endodontic treatment of a total of 303 teeth with pulpitis and periodontitis was performed with a new calcium-carbamide-formaldehyde paste. In three children with fractured teeth with complications, the applied treatment was combined (2 teeth with apical osteotomy and 1 with cystectomy). Control examinations were carried out at months 6, 12 and 24 and clinically healthy teeth and teeth with complications were registered.', 'In the pulpitis group the clinically healthy teeth were 97.55% +/- 1.08 at the 6th month; 96.85% +/- 1.26 at the 12th month and 92.92% +/- 2.41 at the 24th month. In teeth with periodontitis 91.56% +/- 3.05 were clinically healthy at the 6th month; 93.83% +/- 2.67 at the 12th month and 98.03% +/- 1.98 at the 24th month. No statistical significance of the differences between pulpites and periodontites was found (P > 0.05). Recovery of the bone structure was observed in the teeth with combined endodontic and surgical treatment at the 12th month.
Answer: The calcium-carbamide-formaldehyde paste stimulates bone regeneration and closing of the apex without coloring the hard dental tissues.
answer:

Do endodontic treatment of permanent teeth in children with a new calcium-carbamide-formaldehyde paste?