The aim of the present study was to investigate the effects of a calcium hydroxide-based intracanal medication (ICM) on periodontal and endodontic infectious/inflammatory contents and on periodontal clinical parameters in teeth with primary periodontal lesion and secondary endodontic involvement.Ten patients with abnormal pulp test results and deep probing depth derived from primary periodontal disease with secondary endodontic involvement were included. Samples were collected from root canals (RC) and periodontal pockets (PP) in order to investigate the microbiological status, levels of endotoxin (LPS), cytokines, and matrix metalloproteinases (MMP), before and after ICM. PCR was used for microbiological assessment. The kinetic-chromogenic LAL assay was used for LPS quantification. Quantikine ELISA kits were used for measurement of IL-1 α, IL-1 β, TNF-α, PGE2, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-13 levels. The statistical analyses were made using the Friedman and Wilcoxon tests (p 0.05); however, the levels of the other MMPs and cytokines were reduced (p < 0.05). After 1 year of the root canal treatment, tooth mobility was significantly reduced (p ≤ 0.05).The use of a calcium hydroxide-based ICM showed positive effects for periodontal treatment prognosis, as it reduced LPS, cytokine, and MMP levels in periodontal pockets.Patients presenting deep probing depth and undergoing periodontal treatment for at least 6 months, with no positive response to periodontal therapy, might benefit with the endodontic treatment.
This study aims to compare the bone tissue reaction, setting time, solubility, and pH of NeoMTA Plus, Biodentine (BD), and MTA Angelus (MTA-A).Initial and final setting times (n = 7) and solubility up to 7 days (n = 11) were evaluated in accordance with ASTM C266–15 and ANSI/ADA Specification No. 57, respectively. pH (n = 10) was measured up to 28 days. Bone tissue reactions in 48 rats’ femur were histologically analyzed after 7, 30, and 90 days. ANOVA and Tukey’s tests compared setting time, solubility, and pH data; bone reactions data were compared by Kruskal-Wallis and Dunn’s tests.NeoMTA Plus had longer initial and final setting times than MTA-A and BD (P 0.05) and different from MTA-A (P 0.05). All groups presented no difference from 30 to 90 days (P > 0.05) and had better bone repair at 90 days than at 7 days (P < 0.05).NeoMTA Plus, BD, and MTA-A showed satisfactory setting time, high mass loss, alkaline pH, and allowed bone repair.Calcium silicate-based cements are indicated for multiple clinical situations. NeoMTA Plus and BD showed satisfactory physical-chemical and biological properties, being considered as alternatives to MTA-A, as root repair materials for clinical use.
This study investigated and compared the effectiveness of a phytotherapeutic drug composed of herbal extracts on postsurgical discomfort after mandibular third molar surgery.Eighty-two patients requiring the surgical removal of a mandibular third molar were randomly assigned to receive placebo (group 1), ibuprofen (group 2), and a phytotherapeutic drug (composed of baicalin, 190 mg; bromelain, 50 mg; escin, 30 mg) (group 3). Drugs were administered after tooth extraction twice a day for 5 days. The primary outcome, pain, was evaluated using a visual analogue scale at 2 h, 6 h, 12 h, 24 h, 48 h, and 7 and 10 days after surgery. The secondary outcomes were the changes in maximum mouth opening and facial contours (mm) between baseline and at 24 h, 72 h, and 7 and 10 days after surgery.Compared to the baseline, all treatments demonstrated an improvement in the primary and secondary outcomes. Moreover, compared to groups 1 and 2, patients in group 3 yielded a significant reduction of the postoperative pain score at 12 h (p < 0.001), 24 h (p = 0.010), and 48 h (p = 0.048) after surgery. The mean reduction of the swelling and trismus was similar between groups.The results of this study suggest that a postoperative administration of a phytotherapeutic drug was found to be effective in postoperative pain management after the surgical removal of impacted mandibular third molars.The phytotherapeutic drug composed of herbal extract determined a decrease in the severity of postoperative pain compared to ibuprofen and placebo.
This in vivo study aimed to compare the marginal discrepancies of zirconia copings manufactured on the basis of two direct intraoral scanning systems and the indirect digitization of a conventional impression.A total of 63 teeth in 23 patients were prepared to receive full-coverage crowns. Subsequently, these teeth were intraorally scanned using CEREC AC Omnicam and Cara TRIOS and a conventional impression was taken with the scannable PVS Flexitime Fast & Scan. The conventional impression was then extraorally digitized using a D700 laboratory scanner. The zirconia copings were manufactured on the basis of the resulting datasets. Silicone replicas of the copings were produced and sectioned for the measurement of the marginal discrepancy under a digital microscope.The statistical analysis showed no significant differences between the two intraoral scanners, the CEREC AC Omnicam (86.09 μm ± 61.46 μm) and the Cara TRIOS (88.95 μm ± 54.46 μm). However, the discrepancies of the zirconia copings obtained from the laboratory scans of conventional impressions (143.29 μm ± 100.71 μm) showed significant differences. Both intraoral scanners achieved a marginal discrepancy below 100 μm, whereas the laboratory scan exhibited considerably higher values.The intraoral scanners tested allow for the production of single-tooth-restorations with an adequate marginal fit, whereas the production of restorations on the basis of the scan of a conventional impression led to vast marginal gaps.The method of digitizing a conventional impression using a laboratory scanner seemed to have reached its limits in the clinical environment.
The aim of this study was to compare mechanical sensitivity on the tongue using quantitative sensory testing (QST) and psychological factors using the General Health Questionnaire (GHQ) between burning mouth syndrome (BMS) patients and healthy participants.Participants comprised 20 female BMS patients (68.1 ± 7.4 years) and 20 healthy females (65.4 ± 4.6 years). Psychological factors were evaluated with GHQ. Tactile detection thresholds (TDT) and filament-prick pain detection thresholds (FPT) were used to evaluate mechanical sensitivity on the tongue in all participants. TDT and FPT were measured on the tongue within both the painful area and the non-painful area in BMS patients, and on the tongue on both sides in healthy participants. As controls, TDT and FPT were measured with Semmes-Weinstein monofilaments on the skin of the mentum and palm in all participants.GHQ scores were significantly higher in BMS patients than in healthy participants (P = 0.024). No significant differences in TDT or FPT on the tongue, mentum, or palm were seen between BMS patients and healthy participants (P > 0.05). BMS patients showed no significant differences in TDT or FPT between the painful and non-painful areas on the tongue (P > 0.05). There were no significant correlations among TDT/FPT and GHQ score in BMS patients (P > 0.05).These findings could indicate a more important role for psychological factors than mechanical sensitivity in BMS pathophysiology.Pain on the tongue in elderly female patients with BMS may be more related to psychological factors.
Indirect CAD/CAM restorations can be fabricated using both subtractive and additive CAD/CAM technology. This study investigated the fracture load of crowns fabricated from three particle-filled composite CAD/CAM materials and one 3D-printed composite material.Lava Ultimate, Cerasmart and Brilliant Crios were used as particle-filled composite CAD/CAM material and els-3D Harz as 3D-printed composite material. For each group, crowns with three different material thicknesses (0.5/1.0/1.5 mm) were fabricated. Control group was composed of ceramic-based CAD/CAM materials e.max CAD and Enamic. Totally, n = 180 crowns were fabricated and adhesively seated on SLA fabricated dies. Thermomechanical loading and fracture testing were performed. The data for fracture loading force were statistically analyzed by two-way ANOVA followed with multiple comparisons by post hoc Tukey’s test (α = 0.05).In contrast to ceramics, all particle-filled composite crowns with 0.5-mm thickness survived fatigue testing. Forces varied statistically significantly. Brilliant Crios showed highest maximum loading force with 1580.4 ± 521.0 N (1.5 mm). Two-way ANOVA indicated that both the material and the thickness affected the fracture load (p < 0.05).Particle-filled composite resin CAD/CAM materials may have advantageous material characteristics compared to ceramic CAD/CAM materials for minimal restoration thicknesses.Composite-based CAD/CAM materials may offer new possibilities in minimally invasive restorative treatment concepts.
The aim was to compare the clinical performance of uncoated and adhesive precoated brackets bonded with either self-etching primer (SEP) or conventional two-step etch and primer method (CEM).The sample consisted of 63 patients with a mean age of 15.20 ± 1.6 years. In group I (n = 15), uncoated brackets and CEM; in group II (n = 16), precoated brackets and CEM; in group III (n = 16), uncoated brackets and SEP; in group IV (n = 16), precoated brackets and SEP were used for bonding. Bonding time, bracket failure rate, and adhesive remnant index (ARI) scores were measured. The mean orthodontic treatment time was 1.13 ± 0.18 years. One-way variance ANOVA was used to determine bonding time differences and the chi-square test was used to determine differences in bracket failure rates and ARI scores.The bonding time was significantly lower for Groups III and IV, when compared to Groups I and II (p < 0.001). The bond failure rates were not different between the groups. Significant difference was observed between the procedures in relation to ARI scores (p < 0.001), which were higher in group IV.Precoated brackets with SEP application significantly reduced chair time without compromising bracket failure rate.Precoated brackets with SEP application can be safely used for bonding. Regarding the mode of failure, this group can be thought as favorable with a reduced risk of enamel tear.
To analyze the potential of human dental pulp stem cells (hDPSCs) for maintaining their undifferentiated status and osteogenic differentiation capacity when arranged in cell sheets (CSs) for future application in bone replacement.CSs were formed after being induced for 10–15 days by clonogenic medium containing additional vitamin C (20 μg/ml). The cell viability of hDPSC4s in the CSs was followed until 96 h using the Live/Dead® assay. The cells of the CSs were enzymatically dissociated and then compared with the original hDPSC4s. The two cell types were characterized immunophenotypically by flow cytometry using specific mesenchymal stem cell-associated markers (CD105, CD146, CD44, STRO-1, and OCT3/4) and non-associated markers (CD34, CD45, and CD14). Osteogenic differentiation was analyzed with the Alizarin red assay.Living cells were observed until 96 h in the CSs. Both cell types exhibited osteogenic differentiation and expressed the specific undifferentiated MSC-associated markers. Cells spontaneously detached from the CSs attached and proliferated at the bottom of the culture dishes.Cells in the hDPSC4s cell sheets survived for at least 96 h. Moreover, the cells in the cell sheets retained their stemness and their osteogenic differentiation potential.Cell sheets of hDPSCs could be employed as natural tri-dimensional structures for treating bone loss. This technique would be useful particularly for critical bone defects or any type of bone defects in patients carrying diseases that impair bone regeneration, such as diabetes mellitus, medication-related osteonecrosis of the jaw (MRONJ), and osteoporosis.
The aim of this study was to evaluate the 24-month clinical performance of universal adhesives on the restoration success of Class I carious lesions.Five different universal adhesives (Gluma Bond Universal (GU), Clearfil Universal (CU), Prime&Bond Elect Universal (PU), All bond Universal (AU), and Single Bond Universal (SU)) were used in the self-etch and etch-and-rinse modes in 42 patients. The study was conducted with 10 groups, with 20 restorations in each group. The restorations were evaluated at baseline and during a 24-month recall using World Dental Federation (FDI) and the US Public Health Service (USPHS) criteria. The changes in the parameters were analyzed using the chi-square test.At the end of 24 months, there was no loss of restoration in any group. According to the USPHS, there was no difference in the baseline and 24-month clinical behavior of the restorations (P ˃ 0.05). However, according to the FDI, when adhesives were used in the self-etch mode, three adhesives (GU, SU, PU) showed marginal incompatibility, and one adhesive showed (GU) marginal discoloration between baseline and the 24-month follow-up evaluation (P < 0.05). There was no significant difference after 24 months between etch-and-rinse and self-etch groups according to the results based on both the USPHS and FDI criteria (P ˃ 0.05).The 24-month clinical performance of the evaluated universal adhesives depends on the adhesive strategy.This study helps clinicians to decide in which mode (etch-and-rinse or self-etch) universal adhesives can be safely used.
To assess if carotid calcifications detected in panoramic radiographs are associated with future events of stroke, and/or ischemic heart diseases over 10–13 years in individuals between 60 and 96 years.Baseline (2001–2004) panoramic radiographs were assessed for evidence of carotid calcifications from individuals with no previous history of stroke and/or ischemic heart diseases. A radiopaque nodular mass adjacent to the cervical vertebrae, at or below the intervertebral space C3–C4, was interpreted as carotid calcification. Annual medical records were searched for ICD 10 codes through 2014.Signs of carotid calcification was demonstrated in 238/635 (37.5%) of the study individuals. Signs of carotid calcification was associated with future stroke and/or ischemic heart diseases (χ 2 = 9.1, OR 1.6, 95% CI 1.2, 2.2, p < 0.002). In individuals 60–72 years, a significant association between radiographic signs of carotid calcification and stroke and/or ischemic heart diseases (χ 2 = 12.4, OR 2.4, 95% CI 1.5, 4.0, p < 0.000) (adjusted for high blood pressure, diabetes type 2, BMI; OR 1.9, 95% CI 1.1, 3.5, p = 0.03). Individuals (60–72 years) with radiographic evidence of carotid calcifications had a mean cumulative stroke and/or ischemic heart diseases survival time of 12.1 years compared to those without such evidence (13.0 years) (log rank Mantel-Cox χ 2 = 10.7, p = 0.001).Evidence of carotid calcifications in panoramic radiographs is associated with an event of stroke and/or ischemic heart diseases in 60–96-year-old individuals.Radiographic evidence of carotid calcifications is associated with stroke and/or ischemic heart diseases. Patients with signs of carotid calcifications should therefore be referred for medical examination.
The aim of the present study was to evaluate the blood cell content, morphological aspects, gene expression of type I collagen, and release of growth factors on an injectable platelet rich fibrin (i-PRF).Blood samples were collected from 15 volunteers to prepare i-PRF samples. Peripheral blood was used as a control group. Blood clot and i-PRF samples were cultured for 10 days. The supernatant of the samples was collected for ELISA immunoassay quantification of PDGF and VEGF growth factors over periods of 1, 8, 24, 72, and 240 h. I-PRF and blood clot samples were biologically characterized using histological and immunohistochemistry analysis for IL-10, osteocalcin, and TGF-β. Scanning electron microscopy (SEM) was used to inspect the fibrin network and distribution of blood platelets and leukocytes. Reverse transcriptase polymerase chain reaction (RT-PCR) method was used to evaluate gene expression for type I collagen.A higher concentration of platelets and lymphocytes was recorded in i-PRF than in peripheral blood (p < 0.05). The release of VEGF was higher in blood clot samples (1933 ± 704) than that for i-PRF (852 ± 376; p < 0.001). Immunohistochemistry showed upregulation of TGF-B, IL-10, and osteocalcin in the i-PRF group. RT-PCR showed increased type I collagen gene expression in i-PRF (p < 0.05). SEM images revealed agglomeration of platelets in some regions, while a fibrin networking was noticeable in the entire i-PRF sample.Injectable platelet rich fibrin becomes a good approach for soft and mineralized tissue healing considering the formation of a three-dimensional fibrin network embedding platelets, leukocytes, type I collagen, osteocalcin, and growth factors. Indeed, the injectable platelet rich fibrin can be indicated in several medical applications regarding bioactivity, simplied technique, and flowable mixing with other biomaterials.Morphological, cell, and protein characterization of platelet rich fibrin provides a better understanding of the clinical effects and improvement of clinical guidelines for several medical applications. Once well physicochemical and biologically characterized, the use of an injectable platelet rich fibrin can be extended to other applications in the field of orthopedics, periodontics, and implant dentistry on the repairing process of both soft and mineralized tissues.
The aim of this randomized controlled clinical trial was to evaluate the possible advantages of adjunctive hyaluronic acid (HA) application in the coronally advanced flap (CAF) procedure in single Miller class I/recession type 1 (RT1) gingival recession treatment.Thirty patients with one recession were enrolled; 15 were randomly assigned CAF + HA and 15 to CAF alone. The recession reduction (RecRed), clinical attachment level gain (CAL-gain), changes in probing pocket depth (PPD) and in the width of keratinized tissue (KT), complete root coverage (CRC), and mean root coverage (MRC) were calculated after 18 months. Post-operative morbidity (pain intensity, discomfort, and swelling) was recorded 7 days after treatment using visual analogue scale (VAS).After 18 months, RecRed was statistically significantly higher in the test group (2.7 mm [1.0]) than in the control group (1.9 mm [1.0]; p = 0.007). PPD were found to be slightly but statistically significantly increased in both groups. No statistically significant difference was found for KT gain between treatments. CRC was 80% for test and 33.3% for control sites (p < 0.05). A MRC of 93.8 ± 13.0% for test and 73.1 ± 20.8% for control sites was calculated (p < 0.05). The test group reported lower swelling and discomfort values 7-days post-surgery (p < 0.05). Statistically significant difference was not found for pain intensity.The adjunctive use of HA was effective in obtaining CRC for single Miller class I/RT1 gingival recession sites.Adjunctive application of HA in the coronally advanced flap procedure may improve the reduction of the recessions and increase the probability of CRC in Miller class I recessions.
AimThe aim of this prospective, non-interventional, multi-center, practice-based study was, firstly, to evaluate the longevity of composite build-ups in endodontically treated teeth (ETT) without post placement and, secondly, to analyze factors influencing the success of these composite build-ups.MethodologyEach of seven general dental practitioners placed up to 50 composite build-ups without additional posts in ETT. Teeth were restricted to incisors, canines, and premolars. Several clinical data were recorded for 192 coronal restorations on ETT in 192 patients. Cox proportional hazard models were applied to analyze associations between clinical factors and time until failure.ResultsWithin a follow-up period of 10years, 167 restorations were judged as successful [mean success time, 110 (105-115) months] and 180 teeth survived [mean survival time, 114 (110-119) months]. The main failure type was fracture of the restoration (n=15). The annual failure rate was 2.4%. In bivariate Cox regression, both factors such as number of restored tooth surfaces and adhesive were significantly associated with the failure rate. In multivariate Cox proportional hazards regression, none of the investigated factors were significantly associated with the failure rate.ConclusionFor composite build-ups in ETT without post placement, high success rates could be found after up to 10years of observation time. Within the limitations of the present study, none of the analyzed factors such as tooth type or number of restored tooth surfaces was a significant predictor for the failure rate.Clinical relevanceEndodontically treated teeth can be successfully directly restored with composite build-ups even when no additional post is inserted.Trial registrationThe study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012882).
The main aim was to evaluate the effect of postponing the curing of the adhesive layer until the first layer of composite resin is applied—hereby oxygen-inhibited layer (OIL) formation and its detrimental effect on the degree of conversion (DC) of self-etch adhesives should be prevented. For this purpose, the degree of conversion and shear bond strength of four current market self-etch adhesives were evaluated, assessing the effect of curing the adhesives anaerobically and then under two different thicknesses of composite resin, and compare this to the samples cured alone and in air.The degrees of conversion were obtained by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, after the samples were prepared on a glass slide. The samples were either light-cured in air or anaerobically under a clear matrix strip alone, under 2 mm of cured composite resin or under 4 mm of cured composite resin. To determine the shear bond strength (SBS), extracted molars were halved and set in acrylic. Prefabricated cured cylinders of composite resin (TPH 3, 2.4 mm in diameter) of two different lengths are placed over the adhesives under the following conditions: light-cured conventionally (2-mm-long cylinder) and light-cured anaerobically under the uncured end of the piece of composite resin (using both 2- and 4-mm-long cylinders as separate treatments). After another incubation for 24 h at 37 °C, the samples were subjected to shearing using the Bisco Shear Bond Strength Tester.The degree of conversion of the one-step self-etch adhesives was not statistically different when cured anaerobically under a clear matrix strip or cured anaerobically under 2 mm of composite resin. These results were greater than those cured under 4 mm. Shear bond strength between samples cured in air and anaerobically were similar under 2 mm of composite resin tubes, while those cured anaerobically under 4 mm of resin showed lower shear bond strength.When cured anaerobically, one-step self-etch adhesives show a greater degree of conversion and no significant difference in degree of conversion and shear bond strength when compared to those cured in air under the same thickness of composite resin.The results obtained from DC and SBS analysis show promise in placing the uncured adhesive under the composite resin and curing both the adhesive and restoration material simultaneously.
To synthesize two different sizes of bioactive glass-coated mesoporous silica nanoparticles (BGN@MSNs) and to investigate their effects on dentinal tubule occlusion and remineralization.Two different sizes of mesoporous silica nanoparticles (MSNs) were synthesized using the Stöber method (368A, 1840A) and coated with bioactive glass nanoparticles (BGNs) using a modified quick alkali-mediated sol-gel method (368B, 1840B). Sensitive tooth disc models were prepared and divided into six groups and the following treatments were applied: group 1—no treatment, group 2—bioglass, group 3—368A, group 4—368B, group 5—1840A, and group 6—1840B. Then, five discs were selected from each group and soaked in 6 wt% citric acid to test acid resistance. Dentinal tubule occlusion and occlusion ratio were observed using field-emission scanning electron microscopy. In vitro mineralization tests using simulated body fluid solution were performed to evaluate the remineralization effect of the treatment.All samples effectively occluded the dentinal tubule and formed a membrane-like layer. After acid treatment, 1840B (group 6) exhibited the highest rate of dentinal tubule occlusion. Remineralization was observed in 368B and 1840B, and 1840B exhibited the fastest remineralization.Dentinal tubule remineralization induced by the BGN@MSN biocomposite can be used to stabilize long-term prognosis in dentin hypersensitivity. The 1840B induced the most efficient remineralization, and its smaller size and larger surface area were effective for remineralization.The BGN@MSN biocomposite with its smaller size and larger surface area was more effective for remineralization and dentinal tubule sealing.
To evaluate the effects of hexametaphosphate microparticles (mHMP) or nanoparticles (nHMP) incorporated in glass ionomer cement (GIC) on antimicrobial and physico-mechanical properties, fluoride (F) release, and enamel demineralization.HMP solutions were obtained at concentrations of 1, 3, 6, 9, and 12%, for screening of antimicrobial activity. Next, mHMP or nHMP at 6, 9, and 12% were incorporated into a resin-modified GIC and the antibacterial activity was evaluated. The resistance to diametral tensile and compressive strength, surface hardness, and degree of monomer conversion as well as F and HMP releases of GICs were determined. Furthermore, specimens were attached to enamel blocks and submitted to pH-cycling, and mineral loss was determined. Parametric and non-parametric tests were performed, after checking data homoscedasticity (p < 0.05).HMP solutions at 6, 9, and 12% demonstrated the best antibacterial activity. GIC containing HMP showed better antibacterial effects at 9 and 12% for nHMP. Regarding F and HMP releases, the highest levels of release occurred for groups containing 9 and 12% nHMP. With the increase in HMP concentration, there was lower mineral loss. However, the incorporation of mHMP or nHMP in GIC reduced values of physico-mechanical properties when compared to the control GIC.nHMP improves antimicrobial activity and fluoride release, and decreases enamel demineralization, but reduces the physico-mechanical properties of GIC.The association of GIC/HMP could be an alternative material for patients at high risk for dental caries and could be indicated for low-stress regions or provisional restorations.
Platelet-rich fibrin (PRF) has been utilized in regenerative dentistry as a supra-physiological concentrate of autologous growth factors capable of stimulating tissue regeneration. Due to the variability in the macroscopic morphology/size of PRF membranes observed between patients, we were interested in studying the effects of patient age, gender, and time between blood draw and the start of centrifugation on the size outcomes of PRF membranes. Despite PRF therapy being increasingly more popular in private practice, to date, no study has investigated the effects of the delay between blood draw and the start of centrifugation in a clinical setting.A total of 60 patients enrolled in this study were divided into 6 groups of 10 patients each, including male and female patients categorized into age groups 21–40, 41–60, and 61–80 years. From each patient, a total of five PRF membranes were fabricated from 10-mL tubes following centrifugation starting after 0, 30, 60, 90, and 120 s. In total, 300 PRF membranes were produced in this study to investigate the effects of patient age, gender, and time on the size outcomes of PRF membranes.A longer delay by the clinician before starting centrifugation following blood draw led to a smaller final size of PRF membranes. At 90 s following blood draw, a significant (13%) reduction in PRF membrane size was observed. After 120 s, a significant (23%) reduction was observed. Additionally, female patients had on average 17% larger membranes compared to men (p < 0.05, 300 samples). Lastly, the size outcomes of the PRF membranes was largest in patients aged 61–80, followed by those aged 41–60 and 21–40. However, no statistically significant differences in PRF membrane sizes were reported between age groups.The time at which a centrifugation procedure begins following blood draw is critical to optimize the size outcomes of PRF membranes. In general, approximately 15 s is required per tube to harvest 9–10 cc of blood. Therefore, a 60- to 90-s interval between blood draw and the start of centrifugation should be a parameter that is respected by clinicians to avoid significant changes in the macroscopic morphology/size of fabricated PRF membranes. Furthermore, females and older patients produced larger membranes, likely due to lower red blood cell counts derived from their peripheral blood.The findings from the present study demonstrate that on average, a clinician has approximately 60–90 s between blood draw and the start of the centrifugation cycle to produce standard-sized PRF membranes. Shortly thereafter, a significant reduction in size is observed. Additionally, females and older patients were found to produce larger PRF membranes. Centrifugation protocols may therefore be adapted accordingly.
This single-blind, parallel, randomized clinical trial evaluated the genotoxic potential and effectiveness of 10% hydrogen peroxide (HP) in patients submitted to at-home bleaching.Sixty young volunteers with maxillary incisors equal to or darker than M1.5 were included in the study. Patients were submitted to bleaching for 14 days (30 min/day) with one of the three 10% HP treatments: the bleaching agent was delivered in a bleaching tray (White Class, FGM), whitening strips (White Strips, Oral-b), or in prefilled disposable trays (Opalescence Go, Ultradent). The color change was evaluated with the Vita Bleachedguide, and the micronucleus test of exfoliative oral mucosa was carried out, starting from a count of 1000 cells, at the baseline, immediately after and 30 days after the end of the treatment. The micronucleus data were evaluated with the Kruskal-Wallis and Wilcoxon tests and color change with the two-way ANOVA test and the Tukey test (α = 0.05).Significant whitening was observed for all groups after 14 days (p = 0.001) and was maintained after 30 days, with no difference between groups (p = 0.42). The micronucleus count did not indicate genotoxic potential in any of the groups studied (p = 0.32), irrespective of the time intervals (p = 0.62).No genotoxic effects of 10% HP were observed in patients submitted to at-home bleaching systems (30 min/day for 14 days), even 30 days after the end of treatment.It is safe to use different systems to deliver 10% HP during at-home bleaching according to the manufacturers’ recommendations, with no risk of genotoxic effects applied.
ObjectivesThe current study aimed to investigate the effects of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) overexpressing dental pulp stem cells (DPSCs) in vascularized dental pulp regeneration in vivo.Materials and methodsHuman DPSCs were transfected with VEGF or SDF-1 using premade lentiviral particles. Overexpression was verified by quantitative polymerase chain reaction (q-PCR), enzyme-linked immunosorbent assay (ELISA), and western blot analysis. Effects of SDF-1 and VEGF overexpressing DPSCs on their proliferation (CCK-8 and MTT assays) and endothelial vascular-tube formation (Matrigel assay) were investigated in vitro. Human tooth roots sectioned into 6-mm segments were injected with gene-modified DPSCs encapsulated in PuraMatrix hydrogel and implanted in the dorsum of severe-combined-immunodeficient (SCID) mice. Implants were retrieved after 4weeks and examined for regenerated pulp-like tissue and vascularization using histology and immunohistochemistry. p<0.05 was considered statistically significant.ResultsGene-modified DPSCs expressed significantly high levels (p<0.05) of SDF-1 and VEGF mRNA and proteins, respectively. Transfected DPSCs showed a significantly higher cell proliferation compared to that of wild-type DPSCs. Furthermore, they enhanced endothelial cell migration and vascular-tube formation on Matrigel in vitro. When injected into tooth root canals and implanted in vivo, DPSCs/SDF-1 + DPSCs/VEGF-mixed group resulted in significantly increased length of regenerated pulp-like tissue within the root canals compared to that of wild-type DPSCs/VEGF and DPSCs/SDF-1 groups. Vessel area density was significantly higher in DPSCs/SDF-1 and mixed DPSCs/SDF-1 + DPSCs/VEGF groups than in DPSCs-VEGF alone or wild-type DPSCs groups.ConclusionA combination of VEGF-overexpressing and SDF-1-overexpressing DPSCs could enhance the area of vascularized dental pulp regeneration in vivo.Clinical relevanceEnhancing vascularization in pulp regeneration is crucial to overcome the clinical limitation of the limited blood supply to the root canals via a small apical foramen enclosed by hard dentin.
Aim was to assess the influence of a standard autoclaving protocol on the retention of zirconia abutments glued on titanium bases in two-piece implant abutments. Twenty-four CAD/CAM-generated zirconia abutments were adhesively cemented on prefabricated titanium bases. Before mechanical and thermal aging, the specimens were divided into two groups. Group 1 was subjected to a standard steam autoclaving protocol and Group 2 remained untreated (control). The tensile strength in all specimens was evaluated by a standardized pull-off test limited to a maximum force of 1000 N. Eleven samples in both groups could be subjected to pull-off testing. Ten samples in Group 1 and three samples in Group 2 failed, while all others reached the maximum pull-off force. This difference was statistically significant. The mean retention values for the failed samples were 694.53 ± 369.10 N in Group 1 and 890.78 ± 25.90 N in Group 2. This difference was not statistically significant. A standard autoclaving protocol does not reduce detachment force of two-piece zirconia abutments. Clinical sterilization processes as recommended by regulatory authorities seem to be harmless to the structural integrity of two-piece zirconia implant abutments, at least with regard to the retention of the components.