Biomineralization potential and biological properties of a new tantalum oxide (Ta2O5)-containing calcium silicate cement.

OBJECTIVE: The present study evaluated the biological effects and biomineralization potential of a new tantalum oxide (Ta2O5)-containing material designed for vital pulp therapy or perforation repair (NeoMTA 2), compared to NeoMTA Plus and Bio-C Repair. MATERIAL AND METHODS: Human dental pulp stem cells (hDPSCs) were exposed to different eluates from NeoMTA Plus, NeoMTA 2, and Bio-C Repair. Ion release from each material was determined using inductively coupled plasma-optical emission spectrometry (ICP-MS). The biological experiments performed were MTT assays, apoptosis/necrosis assays, adhesion assays, migration assays, morphology evaluation, and reactive oxygen species (ROS) production analysis. Biomineralization was assessed by Alizarin red S staining. Finally, osteo/odontogenic gene expression was determined by real-time quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR). Data were analyzed using one-way ANOVA followed by Tukey's multiple comparison test. RESULTS: NeoMTA 2 displayed a significantly higher calcium release compared to the other materials (p < 0.05). When hDPSCs were cultured in presence of the different material eluates, all groups exhibited similar hDPSC viability and migration rates when compared to untreated cells. Substantial cell attachment and spreading were observed in all materials' surfaces, without significant differences. hDPSCs treated with NeoMTA 2 displayed an upregulation of ALP, Col1A1, RUNX2 (p < 0.001), ON, and DSPP genes (p < 0.05), and showed the highest mineralization potential compared to other groups (p < 0.001). Finally, the more concentrated eluates from these materials, specially NeoMTA Plus and NeoMTA 2, promoted higher ROS production in hDPSCs compared to Bio-C Repair and control cells (p < 0.001), although these ROS levels did not result in increased cell death. CONCLUSIONS: The new tantalum oxide (Ta2O5)-containing material shows an adequate cytocompatibility and the ability to promote biomineralization without using chemical osteogenic inducers, showing great potential as a new material for vital pulp therapy. CLINICAL RELEVANCE: NeoMTA 2 seems to be a promising material for vital pulp therapy. Further studies considering its biocompatibility and biomineralization potential are necessary.

Cytocompatibility and bioactive properties of the new dual-curing resin-modified calcium silicate-based material for vital pulp therapy.

OBJECTIVE: The aim of the present study was to evaluate the in vitro biocompatibility of Theracal PT, Theracal LC, and MTA Angelus, considered as bioactive materials used for vital pulp treatment, on human dental pulp stem cells (hDPSCs). MATERIALS AND METHODS: Human dental pulp stem cells (hDPSCs) were isolated from third molars, and material eluates were prepared (undiluted, 1:2, and 1:4 ratios). The hDPSC cytotoxicity, adhesion, morphology, viability, and cell migration were assessed. The mineralization nodule formation was determined by Alizarin red S staining (ARS). The odonto/osteogenic differentiation potential was assessed by osteo/odontogenic marker expression real-time qPCR. The chemical composition and ion release of the vital pulp materials were determined by energy dispersive X-ray (EDX) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Statistical differences were assessed by ANOVA and Tukey's test (p < 0.05). RESULTS: The three vital pulp materials showed variable levels of calcium, tungsten, silicon, and zirconium release and in their chemical composition. Cytocompatibility assays revealed higher hDPSC viability and migration rates when treated with Theracal PT than with Theracal LC. The lowest cell adhesion and spreading were observed in all Theracal LC-treated groups, whereas the highest were observed when treated with MTA. Theracal PT and MTA promoted the upregulation of DSPP and RUNX2 gene expression (p < 0.05). After 21 days, both MTA Angelus and Theracal PT-treated cells exhibited a significantly higher mineralized nodule formation than the negative control (p < 0.05). CONCLUSIONS: This study demonstrates the favorable in vitro cytocompatibility and bioactive properties of the recently introduced Theracal PT and the well-established MTA Angelus on hDPSCs, as opposed to Theracal LC. More studies, including in vivo animal testing are suggested before these new formulations might be used in the clinical setting. CLINICAL RELEVANCE: Theracal PT is a new material that could be clinically suitable for vital pulp therapy. Further studies considering its biocompatibility and bioactivity are necessary.

Microstructural composition, ion release, and bioactive potential of new premixed calcium silicate-based endodontic sealers indicated for warm vertical compaction technique.

OBJECTIVE: The aim of this study was to evaluate the microstructural composition, ion release, cytocompatibility, and mineralization potential of Bio-C Sealer ION+ (BCI) and EndoSequence BC Sealer HiFlow (BCHiF), compared with AH Plus (AHP), in contact with human periodontal ligament cells (hPDLCs). MATERIALS AND METHODS: The sealers' ionic composition and release were assessed using energy-dispersive spectroscopy (EDS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. For the biological assays, hPDLCs were isolated from third molars, and sealer extracts were prepared (undiluted, 1:2, and 1:4 ratios). An MTT assay, wound-healing assay, and cell morphology and adhesion analysis were performed. Activity-related gene expression was determined using RT-qPCR, and mineralization potential was assessed using Alizarin Red staining (ARS). Statistical analyses were performed using one-way ANOVA and Tukey's post hoc test (α < 0.05). RESULTS: The three sealers exhibited variable levels of silicon, calcium, zirconium, and tungsten release and in their composition. Both BCI and BCHiF groups showed positive results in cytocompatibility assays, unlike AHP. The BCHiF group showed an upregulation of CAP (p < 0.01), CEMP1, ALP, and RUNX2 (p < 0.001) compared with the negative control, while the BCI group showed an upregulation of CEMP1 (p < 0.01), CAP, and RUNX2 (p < 0.001). Both groups also exhibited a greater mineralization potential than the negative and positive controls (p < 0.001). CONCLUSIONS: The calcium silicate-based sealers considered in the present in vitro study exhibited a high calcium ion release, adequate cytocompatibility, upregulated osteo/cementogenic gene expression, and increased mineralized nodule formation in contact with hPDLCs. CLINICAL RELEVANCE: From a biological perspective, BCI and BCHiF could be clinically suitable for root canal filling.

Production of 1,3-propanediol from pure and crude glycerol using a UASB reactor with attached biomass in silicone support.

The 1,3-propanediol (1,3-PDO) yield and productivity from glycerol were studied over a 155-day period. A UASB reactor that also contained silicone support for biomass attachment was used to evaluate the optimal operational conditions and microbiota development. The highest average 1,3-PDO yield was 0.54 and 0.48 mol.mol-gly-1 when reactor pH was 5.0-5.5 and the applied loading rate was 18 and 20 g-gly.L-1.d-1 using the pure and crude substrate, respectively. The productivity was close to 7.5 g.L-1.d-1 for both substrates; therefore, the direct use of crude glycerol can be valorized in practice. Clostridium was the predominant genus for 1,3-PDO production and C. pasteurianum was dominant in the biofilm. Using crude glycerol, C. beijerinckii dropped strongly; some Clostridium population was then replaced by Klebsiella pneumoniae and Lactobacillus spp. The good process performance and the advances in the microbiota knowledge are steps forward to obtain a more cost-effective system in practice.

Long-term complications of silicone and hydrogel explants in retinal reattachment surgery.

OBJECTIVE: To compare long-term complications of silicone sponge, silicone rubber, and MIRAgel used as episcleral buckling elements. METHODS: Medical reports were reviewed of 805 patients with cryotherapy and episcleral buckle for rhegmatogenous retinal detachment who were operated on by 1 of us (M.R.-P.) between March 1984 and December 1997. Average follow-up was 76 months. Symptoms and signs of infection or rejection were considered. Care was taken in buckling element removal, considering the material used for scleral buckling (detailed operative note), duration of the buckle, cause of removal, and culture of the removed element. RESULTS: A total of 757 patients were included in the study. Removal of the implant was necessary in 10 patients (1.3%). Silicone sponge (3 [9%] of 32 patients) was more frequently removed than was silicone rubber (2 [0.6%] of 360 patients) or MIRAgel (5 [1.3%] of 386 patients). Silicone sponge needed to be removed a short time after surgery, showing symptoms of acute infection and positive cultures. Silicone rubber was removed 1 year after surgery with symptoms of chronic infection and positive cultures, and MIRAgel implants were removed after long-term follow-up (7-10 years), showing positive cultures in only 20%. CONCLUSION: Periodic long-term follow-up previously recommended for use of other materials also must be recommended for MIRAgel use because of long-term alterations in its chemical composition and eventual swelling of material.

Astigmatism induced by intrastromal corneal suture after small incision phacoemulsification.

PURPOSE: To evaluate the course of astigmatic evolution and complications after clear corneal incisions using an intrastromal corneal suture. SETTING: Instituto Oftalmologico de Alicante, University of Alicante, Spain. METHODS: Eighty eyes of 62 patients had endocapsular phacoemulsification. A foldable intraocular lens was implanted through a 4.0 mm clear corneal incision. A 10-0 nylon intrastromal corneal suture was used in all eyes. Change sin corneal astigmatism were calculated by vector analysis; follow-up was 6 months. Early and late suture-related complications were also evaluated. RESULTS: Mean induced cylinder was 1.25 diopters (D) +/- 1.24 (SD) with the wound 1 day postoperatively and 0.19 +/- 0.81 D against the wound at 6 months. There were no incision- or suture-related complications postoperatively. CONCLUSION: Use of the intrastromal corneal suture led to astigmatically neutral closure of multiplanar corneal incisions.

[Bioadhesives in ocular surgery]. / Bioadhesivos en cirugía ocular.

PURPOSE: To evaluate the histological inflammatory activity that bioadhesives such as fibrin, cyanoacrylate, unsutured valved closure and suturing, generate when applied on scleral tissue. METHODS: We used a total of 80 eyes of 80 white rabbits which we divided into 8 groups of ten eyes each and distributed according to the two periods of time (1 week and 30 days) and four technique used for closure: 10/0 nylon suture, sutureless self-sealing, cyanoacrylate glue (Histoacryl), and fibrin glue (Tissucol). ANOVA was used for the statistical study of histological inflammation. Descriptive statistical analysis was used for the study of the degree of healing. RESULTS: After 7 days, the fibrin bioadhesive led to greater inflammatory response than did the other techniques (p<0.001). The cyanoacrylate adhesive caused less inflammatory activity than did suturing material (p<0.005). On day 30, the inflammatory reaction generated by the fibrin and cyanoacrylate adhesives was greater than of the suturing and self valved closure technique (p<0.005). After 7 days, the degree of healing with the suture, sutureless technique and cyanoacrylate adhesive was incomplete, while healing was moderate with the fibrin glue. After 30 days the degree of healing with cyanoacrylate glue was incomplete. At this time the degree of healing, with the suture, sutureless technique and fibrin adhesive was complete. CONCLUSIONS: Fibrin causes greater inflammatory reaction than do the other techniques. The cyanoacrylate adhesive shows a biological tolerance identical to the suture technique. This shows that cyanoacrylate bioadhesives are a viable alternative to suturing in scleral surgery.

[ADAL-1(R): a new synthetic adhesive for use in strabismus surgery]. / ADAL-1(R): Nuevo adhesivo sintético de uso en cirugía del estrabismo.

PURPOSE: To evaluate the efficacy and tolerance of ADAL-1(R), a new adhesive in strabismus surgery. METHODS: Three groups of 10 eyes each of 30 albino rabbits underwent superior rectus muscle recession 4 mm, 1(st) group of 10 eyes using the new adhesive, sacrified after one week, 2(nd) group of 10 eyes also with ADAL-1(R), sacrificed after one month and the 3(rd) group (control) of 10 eyes using Dexon 6/0 suture, sacrificed after one month. Clinical evaluation was done at the 1(st) postoperative day, at one week and at one month. The presence of residue of the adhesive, its hardness and the condition of the muscle were all studied after sacrificing the animal. Descriptive study was done for the 1(st) and the 2(nd) group, within the 2(nd) group significant changes along the follow up period were studied using the Friedman test and also differences between the 2(nd) and the suture group were examined using the Fisher's Exact Test. RESULTS: The inflammatory reaction was evaluated between absent and mild in 80% of the cases, both in the 2(nd) and the control group. In the ADAL-1(R) group there were significant statistical differences between 1(st) and 4(th) week (p=0.0002). In the 2(nd) group, 80% of the muscles were attached to the planed position and 20% were slightly displaced, while in the control group 90% of the muscles were attached to the planed position, and 10% were slightly displaced, however there is no significant difference between the two groups p=0.5 (Fisher's Exact Test). CONCLUSION: ADAL-1(R), a new adhesive, could replace sutures in strabismus surgery, giving rise to a rapid and efficient adhesion between muscles and sclera and well tolerated by the ocular tissues.

[Comparative study between different conjunctival tissue adhesives]. / Estudio comparativo entre diferentes adhesivos conjuntivales.

PURPOSE: To evaluate efficacy and clinical and histopathological tolerance of a new acrylic tissue adhesive (ADAL-2) compared to sutures (Vicryl) and other available tissue adhesives (Tisuacryl) for their use in conjunctival surgery. METHODS: This was an experimental study performed in New Zealand albino rabbits with conjunctival dissection and closure by ADAL-2. Groups treated with Vicryl and Tisuacryl were compared regarding efficacy, clinical, and histological tolerance at 7, 28 and 42 days. RESULTS: Efficacy was similar in the three methods of conjunctival repositioning evaluated. Tolerance to ADAL-2 was similar to that of Vicryl suture and tolerance to ADAL-2 was superior to that to Tisuacryl. Histopathological results with ADAL-2 and Tisuacryl are similar. CONCLUSIONS: ADAL-2 tissue adhesive is an efficient and very well tolerated alternative for conjunctival closure in ophthalmic surgery.