Immediate Autotransplantation of Molars with Closed Apex.

AIM: The aim of this study was to evaluate clinical features that might be related to success rates of autotransplantation of molars with complete root formation. MATERIALS AND METHODS: A group of 60 patients with completely formed third molars autotransplanted to a different molar socket was followed for a medium period of 5 years and 5 months. Extreme care was used in order to preserve the vitality of the periodontal ligament cells. The same technique was applied for all teeth despite different anatomies. Descriptive statistics was performed. The association of the various factors with failures was assessed by using the Fisher's exact test and a p-value of 0.05 was considered as significance threshold. RESULTS: Autotransplantation was found to be a reliable method to replace extracted molar teeth with closed apices. The two major factors that positively influenced the outcomes were fixation with splint and a periodontal probing pocket depth less than 4 mm after the initial healing period. The technique resulted in a suitable well-conserved socket and donor tooth, after the extraction. CONCLUSION: An accurate case evaluation was critically important in order to identify the risks prior to surgery and to select the right patients for this procedure. Autotransplantation of third molar teeth is a feasible approach to replace compromised mature molars. Proper stabilization of the transplanted tooth is strategical for the success of this procedure. A conservative approach to unerupted wisdom teeth is also recommended. CLINICAL SIGNIFICANCE: Dental implants and fixed prostheses have been utilized to replace missing teeth, and orthodontic space closure can be sometimes an effective treatment option. Tooth autotransplantation can be a reliable and less invasive clinical alternative when an appropriate donor site is available.

Effect of hydrogel-based antibiotic intracanal medicaments on crown discoloration.

OBJECTIVES: This study evaluated the effects of low and moderate concentrations of triple antibiotic paste (TAP) and double antibiotic paste (DAP) loaded into a hydrogel system on crown discoloration and explored whether application of an adhesive bonding agent prevented crown discoloration. MATERIALS AND METHODS: Intact human molars (n = 160) were horizontally sectioned 1 mm apical to the cementoenamel junction. The crowns were randomized into 8 experimental groups (calcium hydroxide, Ca[OH]2; 1, 10, and 1,000 mg/mL TAP and DAP; and no medicament. The pulp chambers in half of the samples were coated with an adhesive bonding agent before receiving the intracanal medicament. Color changes (ΔE) were detected by spectrophotometry after 1 day, 1 week, and 4 weeks, and after 5,000 thermal cycles, with ΔE = 3.7 as a perceptible threshold. The 1-sample t-test was used to determine the significance of color changes relative to 3.7. Analysis of variance was used to evaluate the effects of treatment, adhesive, and time on color change, and the level of significance was p < 0.05. RESULTS: Ca(OH)2 and 1 and 10 mg/mL DAP did not cause clinically perceivable tooth discoloration. Adhesive agent use significantly decreased tooth discoloration in the 1,000 mg/mL TAP group up to 4 weeks. However, adhesive use did not significantly improve coronal discoloration after thermocycling when 1,000 mg/mL TAP was used. CONCLUSIONS: Ca(OH)2 and 1 and 10 mg/mL DAP showed no clinical discoloration. Using an adhesive significantly improved coronal discoloration up to 4 weeks with 1,000 mg/mL TAP.

Use of electromagnetic stimulation on an Enterococcus faecalis biofilm on root canal treated teeth in vitro.

Root canal disinfection is of utmost importance in the success of the treatment, thus, a novel method for achieving root canal disinfection by electromagnetic waves, creating a synergistic reaction via electric and thermal energy, was created. To study electromagnetic stimulation (EMS) for the disinfection of root canal in vitro, single rooted teeth were instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with Enterococcus faecalis ATCC 29,212, which grew for 15 days to form an established biofilm. Samples were treated with 6% sodium hypochlorite (NaOCl), 1.5% NaOCl 1.5% NaOCl with EMS, 0.9% saline with EMS or 0.9% saline. After treatments, the colony forming units (CFU) was determined. Data was analyzed by Wilcoxon Rank Sums Test (α = 0.05). One sample per group was scored and split for confocal laser scanning microscopy imaging. There was a significant effect with the use of NaOCl with or without EMS versus 0.9% saline with or without EMS (p = 0.012 and 0.003, respectively). CFUs were lower when using 0.9% saline with EMS versus 0.9% saline alone (p = 0.002). Confocal imaging confirmed CFU findings. EMS with saline has an antibiofilm effect against E. faecalis and can potentially be applied for endodontic disinfection.

Effect of Hydrogel-Based Antibiotic Intracanal Medicaments on Push-Out Bond Strength.

OBJECTIVE: This study aimed to evaluate the effects of typical clinical concentration (1,000 mg/mL), low concentration (1 mg/mL) triple antibiotic pastes (TAP), and double antibiotic pastes (DAP) on the bond strength between various root cements and radicular dentin. MATERIALS AND METHODS: Intact single-rooted human teeth (n = 144) were horizontally decoronated and canals instrumented. The roots were treated for 4 weeks with Ca(OH)2, 1,000 mg/mL of TAP or DAP, and 1 mg/mL of TAP or DAP. Untreated roots served as a control. After treatment, the medicaments were irrigated and each group was divided into three subgroups receiving MTA, Biodentine, or Endosequence putty cement. After 2 weeks, coronal and middle root cylinders were obtained from each root. Push-out bond strength test and failure analysis were performed for all root cylinders. STATISTICAL ANALYSIS: Three-way ANOVA, pairwise comparisons and logistic regression were used for statistical analyses. A significance level of 5% was used. RESULTS: For MTA applied in the coronal part of the roots, 1 mg/mL DAP and TAP and Ca(OH)2 demonstrated significantly higher bond strength compared with the typical clinical concentration and the control groups. For Biodentine applied coronally in the roots, 1 mg/mL of DAP resulted in significantly higher bond strength than all other groups. For Endosequence putty cement applied coronally in the roots, 1 mg/mL of DAP offered significantly higher bond strength than all groups except for Ca(OH)2. CONCLUSION: The use of 1 mg/mL DAP resulted in significantly higher push-out bond strength compared with the typical clinical concentration of TAP and DAP regardless of the type of the root cement used.

Curcumin-A Natural Medicament for Root Canal Disinfection: Effects of Irrigation, Drug Release, and Photoactivation.

INTRODUCTION: Curcumin incorporation into polymeric fibers was tested for its antimicrobial properties and potential use in root canal disinfection. METHODS: Curcumin-modified fibers were processed via electrospinning and tested against a 7-day old established Actinomyces naeslundii biofilm. The medicaments tested were as follows: curcumin-modified fibers at 2.5 and 5.0 mg/mL, curcumin-based irrigant at 2.5 and 5.0 mg/mL, saline solution (negative control), and the following positive controls: 2% chlorhexidine, 1% sodium hypochlorite, and triple antibiotic paste (TAP, 1 mg/mL). All medicaments, except for the positive controls, were allocated according to the light exposure protocol (ie, photoactivation with a light-emitting diode every 30 seconds for 4 minutes or without photoactivation). After treatment, the medicaments were removed, and 1 mL saline solution was added; the biofilm was scraped from the well and used to prepare a 1:2000 dilution. Spiral plating was performed using anaerobic blood agar plates. After 24 hours, colony-forming units (colony-forming units/mL, n = 11/group) were counted to determine the antimicrobial effects. RESULTS: Data exhibited significant antimicrobial effects on the positive control groups followed by the curcumin irrigants and, lastly, the photoactivated curcumin-modified fibers. There was a significant reduction of viable bacteria in curcumin-based irrigants, which was greater than the TAP-treated group. Curcumin-free fibers, saline, and the nonphotoactivated curcumin-modified fibers did not display antimicrobial activity. CONCLUSIONS: Curcumin seems to be a potential alternative to TAP when controlling infection, but it requires a minimal concentration (2.5 mg/mL) to be effective. Photoactivation of curcumin-based medicaments seems to be essential to obtain greater antibiofilm activity.

A novel patient-specific three-dimensional drug delivery construct for regenerative endodontics.

Evoked bleeding (EB) clinical procedure, comprising a disinfection step followed by periapical tissue laceration to induce the ingrowth of undifferentiated stem cells from the periodontal ligament and alveolar bone, is currently the only regenerative-based therapeutic approach to treating pulp tissue necrosis in undeveloped (immature) permanent teeth approved in the United States. Yet, the disinfection step using antibiotic-based pastes leads to cytotoxic, warranting a biocompatible strategy to promote root canal disinfection with no or minimal side-effects to maximize the regenerative outcomes. The purpose of this investigation was to develop a tubular three-dimensional (3D) triple antibiotic-eluting construct for intracanal drug delivery. Morphological (scanning electron microscopy), chemical (Fourier transform infrared spectroscopy), and mechanical (tensile testing) characteristics of the polydioxanone-based triple antibiotic-eluting fibers were assessed. The antimicrobial properties of the tubular 3D constructs were determined in vitro and in vivo using an infected (Actinomyces naeslundii) dentin tooth slice model and a canine method of periapical disease, respectively. The in vitro data indicated significant antimicrobial activity and the ability to eliminate bacterial biofilm inside dentinal tubules. In vivo histological findings demonstrated that, using the EB procedure, the tubular 3D triple antibiotic-eluting construct allowed the formation of an appropriate environment that led to apex closure and the ingrowth of a thin layer of osteodentin-like tissue into the root canal. Taken together, these findings indicate that our novel drug delivery construct is a promising biocompatible disinfection strategy for immature permanent teeth with necrotic pulps. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1576-1586, 2019.

Clindamycin-modified Triple Antibiotic Nanofibers: A Stain-free Antimicrobial Intracanal Drug Delivery System.

INTRODUCTION: A biocompatible strategy to promote bacterial eradication within the root canal system after pulpal necrosis of immature permanent teeth is critical to the success of regenerative endodontic procedures. This study sought to synthesize clindamycin-modified triple antibiotic (metronidazole, ciprofloxacin, and clindamycin [CLIN]) polymer (polydioxanone [PDS]) nanofibers and determine in vitro their antimicrobial properties, cell compatibility, and dentin discoloration. METHODS: CLIN-only and triple antibiotic CLIN-modified (CLIN-m, minocycline-free) nanofibers were processed via electrospinning. Scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and tensile testing were performed to investigate fiber morphology, antibiotic incorporation, and mechanical strength, respectively. Antimicrobial properties of CLIN-only and CLIN-m nanofibers were assessed against several bacterial species by direct nanofiber/bacteria contact and over time based on aliquot collection up to 21 days. Cytocompatibility was measured against human dental pulp stem cells. Dentin discoloration upon nanofiber exposure was qualitatively recorded over time. The data were statistically analyzed (P < .05). RESULTS: The mean fiber diameter of CLIN-containing nanofibers ranged between 352 ± 128 nm and 349 ± 128 nm and was significantly smaller than PDS fibers. FTIR analysis confirmed the presence of antibiotics in the nanofibers. Hydrated CLIN-m nanofibers showed similar tensile strength to antibiotic-free (PDS) nanofibers. All CLIN-containing nanofibers and aliquots demonstrated pronounced antimicrobial activity against all bacteria. Antibiotic-containing aliquots led to a slight reduction in dental pulp stem cell viability but were not considered toxic. No visible dentin discoloration upon CLIN-containing nanofiber exposure was observed. CONCLUSIONS: Collectively, based on the remarkable antimicrobial effects, cell-friendly, and stain-free properties, our data suggest that CLIN-m triple antibiotic nanofibers might be a viable alternative to minocycline-based antibiotic pastes.

Chronic fibrosing osteomyelitis of the jaws: an important cause of recalcitrant facial pain. A clinicopathologic study of 331 cases in 227 patients.

OBJECTIVE: This was a retrospective and follow-up analysis of 331 cases of chronic fibrosing osteomyelitis of the jaws (CFOJ) in 227 patients. STUDY DESIGN: Demographic, clinical, surgical, and microscopic characteristics were tabulated for all patients. A follow-up mail survey was used to determine the degree of symptom relief experienced after surgery. RESULTS: The female to male ratio approached 7:1, and mean age of patients was 53 years. The most common sites were the mandibular posterior region, followed by the maxillary posterior region. Consistent clinical findings included intractable jaw pain mimicking that of odontogenic origin but unresponsive to usual therapies, minimal or undetectable radiographic abnormalities on plain films but dramatic radiolucencies detected on cone beam computed tomography, and large cavities that were either empty or filled with blood mixed with lipid globules encountered at surgery. The most common histomorphologic findings were vital lamellar bone, prominent resting and reversal lines, microshards and splaying of trabeculae, rounded trabeculae, marrow fibrosis, and pools of erythrocytes and lipid globules, often together. Moderate to complete relief of symptoms for periods up to 108 months after surgery were reported by 83% of the 70 patients who returned the survey. CONCLUSIONS: On the basis of the findings of this study, CFOJ can be considered a unique entity with consistent clinicopathologic features. Its features suggest a pathogenesis based on bone marrow ischemia. CFOJ can be treated on a rational basis with a justifiable expectation of success and probable cure.

Antibacterial Effects of Antimicrobials Used in Regenerative Endodontics against Biofilm Bacteria Obtained from Mature and Immature Teeth with Necrotic Pulps.

INTRODUCTION: We investigated the direct and residual antibacterial effects of intracanal antimicrobials against bacterial biofilms obtained from infected mature and immature teeth with necrotic pulps. METHODS: Sterile dentin slabs (n = 100) were inoculated with bacterial biofilms obtained from root canals of an immature or a mature tooth with pulpal necrosis and incubated anaerobically for 3 weeks (n = 50 per biofilm). Dentin infected with each type of biofilm received 1 week of treatment with 1 or 5 mg/mL double antibiotic paste (DAP) in methylcellulose hydrogels, calcium hydroxide, or placebo paste or received no treatment (n = 10). The pastes were removed, and biofilm disruption assays were performed. Additional dentin slabs (n = 100) were pretreated with the same treatments (n = 20). The pastes were rinsed off, and the samples were immersed in phosphate-buffered saline for 1 week. Thereafter, samples from the treatment groups were infected with bacterial biofilm from both clinical sources mentioned earlier (n = 10 per biofilm) and incubated anaerobically for 3 weeks before conducting biofilm disruption assays. Uninfected dentin slabs were used for both antibacterial experiments as negative control groups (n = 20). RESULTS: All antimicrobials showed significant direct antibacterial effects regardless of the biofilm source. Dentin pretreated with 5 mg/mL DAP provided significantly higher residual antibacterial effects in comparison with all other groups regardless of the source of biofilm. Dentin pretreated with calcium hydroxide did not show any residual antibacterial effects. CONCLUSIONS: Tested antimicrobials showed significant direct antibacterial effects. Only 5 mg/mL DAP exhibited significant residual antibacterial effects against bacterial biofilms from an infected root canal of an immature tooth.

Direct and indirect antibacterial effects of various concentrations of triple antibiotic pastes loaded in a methylcellulose system.

We investigated the direct and indirect (residual) antibacterial effects of various concentrations of triple antibiotic paste (TAP) loaded into a methylcellulose system. Enterococcus faecalis (E. faecalis) was grown on sterilized dentin blocks (n = 60) and treated with clinically used TAP (1,000 mg/mL), low concentrations of methylcellulose-based TAP (100, 10, and 1 mg/mL), placebo paste, or 1.5% NaOCl (n = 10). The pastes were then removed, and biofilm disruption assays were performed. Additional dentin blocks (n = 120) were pretreated with the same experimental groups (n = 20). The pastes were rinsed off, and the samples were immersed independently in phosphate-buffered saline for 2 and 4 weeks (n = 10). E.faecalis was then grown on the dentin blocks, and biofilm disruption assays were performed. Fisher's Exact and Wilcoxon rank sum tests were used for statistical analyses. With regard to direct antibacterial effects, all treatment groups demonstrated complete eradication of biofilms in comparison to placebo paste, while 10 mg/mL of TAP or higher provided substantial residual antibacterial effects. However, dentin treated with 1 mg/mL of TAP or 1.5% NaOCl did not provide substantial residual antibacterial effects. Dentin pretreated with 10 mg/mL of TAP or higher exhibited extended residual antibacterial effects and can thus be used during endodontic regeneration.(J Oral Sci 58, 575-582, 2016).

Residual antibiofilm effects of various concentrations of double antibiotic paste used during regenerative endodontics after different application times.

OBJECTIVE: We investigated the residual antibiofilm effects of different concentrations of double antibiotic paste (DAP) applied on radicular dentin for 1 or 4 weeks. DESIGN: Dentin samples were prepared (n=120), sterilized and pretreated for 1 or 4 weeks with the clinically used concentration of DAP (500mg/mL), low concentrations of DAP (1, 5 or 50mg/mL) loaded into a methylcellulose system, calcium hydroxide (Ca(OH)2), or placebo paste. After the assigned treatment time, treatment pastes were rinsed off and the samples were kept independently in phosphate buffered saline for 3 weeks. Pretreated dentin samples were then inoculated with Enterococcus faecalis and bacterial biofilms were allowed to grow for an additional 3 weeks. Biofilms were then retrieved from dentin using biofilm disruption assays, diluted, spiral plated, and quantified. Fisher's Exact and Wilcoxon rank sum tests were used for statistical comparisons (α=0.05). RESULTS: Dentin pretreatment for 4 weeks with 5, 50 or 500mg/mL of DAP demonstrated significantly higher residual antibiofilm effects and complete eradication of E. faecalis biofilms in comparison to a 1 week pretreatment with similar concentrations. However, dentin pretreated with 1mg/mL of DAP or Ca(OH)2 did not provide a substantial residual antibiofilm effect regardless of the application time. CONCLUSIONS: Dentin pretreatment with 5mg/mL of DAP or higher for 4 weeks induced significantly higher residual antibiofilm effects in comparison to a 1 week pretreatment with the same concentrations.

Effects of Novel 3-dimensional Antibiotic-containing Electrospun Scaffolds on Dentin Discoloration.

INTRODUCTION: Although intracanal application of the triple antibiotic paste (TAP) may offer advantages (eg, disinfection), this practice has been associated with significant drawbacks, including tooth discoloration. In this study, the color change of dentin was monitored during treatment with distinct TAP pastes and novel tubular-shaped 3-dimensional electrospun scaffolds containing minocycline (MINO) or doxycycline (DOX). METHODS: Two TAP pastes (TAPMINO [MINO, metronidazole, and ciprofloxacin] and TAPDOX [DOX, metronidazole, and ciprofloxacin]), 4 scaffold-based groups containing MINO or DOX at distinct concentrations, 1 antibiotic-free scaffold, and 1 untreated group (control) were investigated. Human canines were sectioned at the cementoenamel junction and tubular-shaped scaffolds or paste were placed into the root canals and sealed. Color measurements (CIEL(*)a(*)b(*) parameters) were performed at baseline and after 1, 3, 7, 14, 21, and 28 days. Color changes were expressed as ΔE(*) values. In addition, scanning electron microscopy and energy-dispersive X-ray spectroscopy were also performed on the specimens after treatment. Data were analyzed using repeated measures analysis of variance (alpha = 0.05). RESULTS: All antibiotic-containing groups led to greater discoloration than the antibiotic-free groups. A severe discoloration occurred after 1 day. At the end of the experiment, antibiotic-treated samples exhibited crusts/agglomerates over the dentin surface, which totally or partially obliterated the dentinal tubules. The presence of MINO resulted in a greater color change than DOX. CONCLUSIONS: Scaffolds containing MINO or DOX produced similar color change to dentin when compared with their respective TAP systems, although DOX-related discoloration was less pronounced.

The effects of radicular dentine treated with double antibiotic paste and ethylenediaminetetraacetic acid on the attachment and proliferation of dental pulp stem cells.

AIM: This study explored the effects of dentine treated with two concentrations of double antibiotic paste (DAP) and ethylenediaminetetraacetic acid (EDTA) on the attachment and proliferation of dental pulp stem cells (DPSCs). MATERIALS AND METHODS: Radicular dentine samples were prepared with identical dimensions and randomized into six groups (n = 4). Four groups were treated with double antibiotic paste (DAP) at concentrations of 500 mg ml(-1) or 1 mg ml(-1) with or without EDTA. The other two groups were treated with EDTA only or received no treatment. DPSCs were seeded on each dentine sample (10 000 cells per sample). Lactate dehydrogenase activity assays were used to calculate the attached DPSCs after 1 day of incubation. Water soluble tetrazolium assays were performed to investigate DPSCs proliferation on the treated dentine samples after three additional days of incubation. Two-way anova followed by Tukey-Kramer tests was used for statistical analyses (α = 0.05). RESULTS: Dentine treated with 1 or 500 mg ml(-1) of DAP followed by EDTA caused significant increases in DPSCs attachment compared to the dentine treated with the DAP alone. The 500 mg ml(-1) of DAP with or without EDTA caused significant reductions in DPSCs proliferation. However, the treatment of dentine with 1 mg ml(-1) of DAP did not have significant negative effects on DPSCs proliferation regardless of the use of EDTA. CONCLUSION: The use of 1 mg ml(-1) of DAP followed by 10 min of irrigation with EDTA in endodontic regeneration procedure may have no negative effects on the attachment and proliferation of DPSCs.

Evaluation of Residual Antibacterial Effect of Human Radicular Dentin Treated with Triple and Double Antibiotic Pastes.

INTRODUCTION: The aim of this study was to investigate the residual antibacterial effect of human radicular dentin treated with various concentrations of triple antibiotic paste and double antibiotic paste (DAP). METHODS: Sterilized dentin specimens were randomly assigned to 6 treatment groups and a no-treatment control group (n = 45 per group). For treatment groups, specimens were treated with either TAP or DAP at various concentrations (1000, 1, or 0.5 mg/mL) for 2 weeks. Then, each specimen was irrigated with 5 mL saline and incubated in phosphate-buffered solutions for 3, 7, 14, or 30 days. After that, Enterococcus faecalis was cultured on the specimens for 3 days. Each specimen was then transferred to a tube containing 200 µL saline, sonicated, and vortexed to detach the bacterial biofilm. The detached biofilm was spiral plated, and the number of colony-forming units was determined using an automated counting machine. RESULTS: Dentin specimens treated with 1000 mg/mL TAP or DAP had a significant residual antibacterial effect up to 14 days and 30 days, respectively. No significant difference was observed between 1000 and 1 mg/mL TAP and DAP at all time points. Dentin treated with all concentrations of DAP has a significantly longer residual antibacterial effect compared with dentin treated with TAP at the same concentrations. CONCLUSIONS: Radicular dentin treated with TAP and DAP showed a significant residual antibacterial effect compared with untreated dentin. All concentrations of DAP showed a significantly longer residual antibacterial effect compared with the same concentrations of TAP.

A novel three-dimensional scaffold for regenerative endodontics: materials and biological characterizations.

An electrospun nanocomposite fibrous material holds promise as a scaffold, as well as a drug-delivery device to aid in root maturogenesis and the regeneration of the pulp-dentine complex. A novel three-dimensional (3D) nanocomposite scaffold composed of polydioxanone (PDS II®) and halloysite nanotubes (HNTs) was designed and fabricated by electrospinning. Morphology, structure, mechanical properties and cell compatibility studies were carried out to evaluate the effects of HNTs incorporation (0.5-10 wt% relative to PDS w/w). Overall, a 3D porous network was seen in the different fabricated electrospun scaffolds, regardless of the HNT content. The incorporation of HNTs at 10 wt% led to a significant (p < 0.0001) fibre diameter increase and a reduction in scaffold strength. Moreover, PDS-HNTs scaffolds supported the attachment and proliferation of human-derived pulp fibroblast cells. Quantitative proliferation assay performed with human dental pulp-derived cells as a function of nanotubes concentration indicated that the HNTs exhibit a high level of biocompatibility, rendering them good candidates for the potential encapsulation of distinct bioactive molecules. Collectively, the reported data support the conclusion that PDS-HNTs nanocomposite fibrous structures hold potential in the development of a bioactive scaffold for regenerative endodontics.

Effects of two combinations of triple antibiotic paste used in endodontic regeneration on root microhardness and chemical structure of radicular dentine.

We investigated the effects of triple antibiotic paste (TAP) and modified triple antibiotic paste (MTAP) concentrations on the microhardness and chemical structure of radicular dentine. Human root cylinders were instrumented and randomized into four treatment groups and an untreated control group. Two treatment groups received 1 g/mL TAP or MTAP, and the other two treatment groups received 1 mg/mL methylcellulose-based TAP or MTAP. Cylinders were stored at 100% relative humidity for 4 weeks. Each root cylinder was subjected to a microhardness test before and after treatment. Different sets of radicular dentine specimens were treated as mentioned previously, and were examined using attenuated total reflection Fourier transform infrared spectroscopy. All treatment groups showed significant reductions in microhardness of roots when compared to untreated control roots at 1,000 and/or 500 µm from the pulp-dentine interface. However, 1 mg/mL methylcellulose-based antibiotics caused significantly less reduction in microhardness when compared to 1 g/mL antibiotics. In addition, 1 g/mL TAP and DAP caused significantly lower phosphate/amide I ratios when compared to other groups. The use of 1 mg/mL methylcellulose-based TAP and MTAP may minimize the reduction in microhardness of roots compared with the currently used 1 g/mL concentration of these antibiotics.

Bimix antimicrobial scaffolds for regenerative endodontics.

INTRODUCTION: Eliminating and/or inhibiting bacterial growth within the root canal system has been shown to play a key role in the regenerative outcome. The aim of this study was to synthesize and determine in vitro both the antimicrobial effectiveness and cytocompatibility of bimix antibiotic-containing polydioxanone-based polymer scaffolds. METHODS: Antibiotic-containing (metronidazole [MET] and ciprofloxacin [CIP]) polymer solutions (distinct antibiotic weight ratios) were spun into fibers as a potential mimic to the double antibiotic paste (DAP, a MET/CIP mixture). Fiber morphology, chemical characteristics, and tensile strength were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy, and tensile testing, respectively. Antimicrobial efficacy was tested over time (aliquot collection) against Enterococcus faecalis (Ef), Porphyromonas gingivalis (Pg), and Fusobacterium nucleatum (Fn). Similarly, cytotoxicity was evaluated in human dental pulp stem cells. Data were statistically analyzed (P < .05). RESULTS: Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed that electrospinning was able to produce antibiotic-containing fibers with a diameter mostly in the nanoscale. The tensile strength of 1:1MET/CIP scaffolds was significantly (P < .05) higher than pure polydioxanone (control). Meanwhile, all other groups presented similar strength as the control. Aliquots obtained from antibiotic-containing scaffolds inhibited the growth of Ef, Pg, and Fn, except pure MET, which did not show an inhibitory action toward Pg or Fn. Antibiotic-containing aliquots promoted slight human dental pulp stem cell viability reduction, but none of them were considered to be cytotoxic. CONCLUSIONS: Our data suggest that the incorporation of multiple antibiotics within a nanofibrous scaffold holds great potential toward the development of a drug delivery system for regenerative endodontics.

Chronic fibrosing osteomyelitis: a position statement.

Chronic Fibrosing Osteomyletis (CFO) is a commonly found condition which is often undiagnosed because of its co-morbidities with other systemic conditions. Clinicians should consider CFO in their differential diagnosis when confronted with complex head, neck and facial pain patients who present with multi-symptom/systems overlay. A multi-disciplinary approach is often required for proper patient diagnosis and treatment.

Susceptibility of methacrylate-based root canal filling to degradation by bacteria found in endodontic infections.

OBJECTIVES: To present a case of endodontic failure obturated with a methacrylate-based root filling material, Resilon/RealSeal (RS). To determine if RS is susceptible to biodegradation by endodontically relevant microbes by a method known to show RS degradation. METHOD AND MATERIALS: Emulsions of RS were dispersed in agar with minimal bacterial nutrients in culture plates. Lipase PS served as a positive control. Pseudomonas aeruginosa, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas gingivalis, Porphyromonas asaccharolytica, Enterococcus faecalis, Streptococcus sanguis, Streptococcus mutans, Staphylococcus aureus, and Staphylococcus epidermidis were tested for their ability to biodegrade RS. The bacteria were inoculated in the plates and examined daily for RS degradation for 7 days. RESULTS: Degradation of the emulsified RS manifested in the formation of clear zones around P aeruginosa, P intermedia, P asaccharolytica, S aureus, and S epidermidis. No degradation was seen with the other tested bacteria or in plates that did not contain RS emulsion. CONCLUSION: Endodontic pathogenic bacteria can degrade RS. These findings complement other work and suggest that the seal and integrity of root canal fillings obturated with RS may be impaired by a microbial insult.