Calcium hydroxide: study based on scientific evidences

An in vitro comparison of calcium ions release and diffusion ability of calcium hydroxide-based intracanal medicament in combination with three different vehicles like propolis, chitosan, and propylene glycol

Context

Calcium hydroxide, which is an intracanal medicament, is widely used in endodontics. Improvements can be made to its effectiveness, as calcium hydroxide is dependent on the vehicle.

Aim

The study aims to compare and evaluate the release and diffusion ability of calcium hydroxide when mixed with - propolis, chitosan, and propylene glycol.

Methods

For this study, 33 single-rooted extracted premolar teeth have been decoronated. After the working length and enlargement of the canals had been established, different preparations of calcium hydroxide with vehicles such as propolis, chitosan, and propylene glycol were loaded into the canals. Atomic absorption spectrophotometry was used to analyze the release of calcium ions in three groups, while a digital pH meter was used to determine an acid change.

Results

Atomic absorption spectrophotometry showed sustained releases of calcium ions and the digital pH meter showed increased diffusion capacity in the propylene glycol paste group in comparison to the other two groups.

Conclusion

Propylene glycol vehicle made it easier to enter calcium hydroxide into the dentinal tubules.

Preliminary in vitro cytotoxic evaluation of Uncaria gambier (Hunt) Roxb extract as a potential herbal-based pulpotomy medicament

BACKGROUND

The downfall of formocresol as a pulpotomy medicament highlights the importance of cytotoxic evaluation and the establishment of a safe concentration of dental material prior to its usage in the oral cavity. Uncaria gambir is an herbal plant that possesses antimicrobial, anti-inflammatory and antioxidant properties, suggesting its potential as an alternative medicament for pulpotomy. However, there are not many studies published on its cytotoxicity, with some using non-standardised techniques and reported variable outcomes. Here, we investigated the concentration and time-dependent toxicity of Uncaria gambir extract towards the M3CT3-E1 cell line and compared it with the gold standard pulpotomy medicament: mineral trioxide aggregate (MTA).

METHODS

Uncaria gambir extracts at concentrations ranging from 1000 to 7.8 µg/ml and MTA eluates at 4- and 48 h setting times were prepared. 10% dimethyl sulfoxide (DMSO) and culture media were used as positive and negative controls respectively. Cell viability on days 1, 2, 3 and 7 was analysed using Alamar Blue and Live and Dead Cell assay. Any morphological cellular changes were evaluated using transmission electron microscopes (TEM). Data were analysed using a two-way mixed Analysis of Variance (ANOVA).

RESULTS

The interaction between the concentration and exposure time on the fluorescence intensity of Uncaria gambir extract and MTA 48 h was found to be statistically significant (p < 0.001). No cytotoxic effects on the cells were exerted by both MTA 48 h and Uncaria gambir extract at a concentration below 500 µg/mL. TEM analysis and Live and Dead Cell assay for both materials were comparable to the negative control. No significant differences in fluorescent intensity were observed between Uncaria gambir extract at 500 µg/mL and MTA 48 h (p > 0.05).

CONCLUSION

Uncaria gambir extracts at a maximum concentration of 500 μg/mL are non-cytotoxic over time and are comparable to the MTA.

Analysis of pH, calcium ion release, and energy dispersive spectroscopy of a bioceramic root canal dressing

This study compared the pH and calcium ion release of calcium silicate- (Bio-C Temp) and calcium hydroxide-based (Ultracal XS) medications. Intracanal remnants of both medications were also evaluated using SEM-EDS after the removal protocol. Thirty-five bovine teeth were prepared. Fifteen were filled with Bio-C Temp and 15 with Ultracal XS. Five remained without intracanal medication (control group). Five samples from each experimental time (i.e.. 24, 72, and 168 hours) were used to measure pH and calcium ions release using a digital pH meter and microplate reader, respectively. Afterward, the peaks of the chemical elements composing both medications were analyzed in SEM-EDS. One-way ANOVA and Tukey's post hoc test analyzed the pH and calcium ion release data. Student's t-test compared the medications in each experimental time. SEM-EDS described the percentage of chemical elements in the samples. Bio-C Temp and Ultracal XS showed a significant pH increase from 24 to 168 hours (p<0.05). Ultracal XS showed a higher pH value at 24 hours than Bio-C Temp (p<0.05) but were similar at 72 and 168h (p > 0.05). Calcium ion release did not depend on the experimental period (p > 0.05). Bio-C Temp showed lower calcium ions release than Ultracal XS at 24 hours (p<0.05). SEM-EDS analyses showed the remains of both medications, but the concentration of Si, Al, and W ions was present only in the calcium silicate-based medication. Bio-C Temp presented alkaline pH and a satisfactory calcium ion release over the time. The remaining of both medications were present after the protocols for paste removal.

Outcome of Regenerative Endodontic Procedures in Non-Vital Immature Permanent Teeth Using Two Intracanal Medications: A Prospective Randomized Clinical Study

INTRODUCTION

This randomized clinical trial aimed to assess and compare the long-term clinical and radiographic outcomes of Regenerative Endodontic Procedures (REP) in treating non-vital immature permanent teeth using two intra-canal medicaments.

METHODS

Forty-five patients yielding a total of 50 anterior and posterior non-vital immature teeth were randomly divided into 2 groups. REP utilizing either non-setting calcium hydroxide (Ca(OH)₂) (n=25) or modified triple antibiotic paste (TAP) (n=25), as intra-canal medicaments were performed. NeoMTA Plus (Avalon Biomed Inc™, Houston, Texas, USA) was applied for coronal sealing. Cases were followed up clinically and radiographically for 36 months. Survival rate, success rate, and clinical outcome measures were analyzed. Preoperative and recall radiographs were evaluated for dimensional changes in root length, dentin thickness, apical diameter, and periapical radiolucency.

RESULTS

At 36 months follow up, success and survival rates were 81.6%, and 100% respectively, in which 79.4% of cases showed complete resolution of periapical radiolucency, with no significant difference between non-setting Ca(OH)2 and modified TAP groups (P>0.050). The cumulative changes in root length, root dentin thickness and apical diameter, throughout the study period, were observed in 47.9%, 77.1%, and 89.6 %, of cases respectively, with no significant differences between both groups (P≥ 0.39). Intra-canal calcifications were detected in 60% of cases with no significant difference between both groups (P=0.77).

CONCLUSIONS

REP, using either non-setting Ca(OH)₂ or modified TAP as intra-canal medicament, exhibited high success and survival rates, over a follow up period of 36 months, with equally favorable clinical and radiographic outcome data.

Mechanism of action of Bioactive Endodontic Materials

A continuous search for bioactive materials capable of supporting the replacement of damaged pulp tissue, with effective sealing potential and biocompatibility, has represented the attention of studies over the last decades. This study involves a narrative review of the literature developed by searching representative research in PUBMED/MEDLINE and searches in textbooks associated with the mechanism of action of bioactive materials (calcium hydroxide, mineral trioxide aggregate (MTA), and calcium silicate cements). The reflective analysis of the particularities of the chemical elements of these materials, considering the tissue and antibacterial mechanism of action, allows a better understanding of the characteristics and similarities in their tissue responses. Calcium hydroxide paste remains the antibacterial substance of choice as intracanal dressing for the treatment of root canal system infections. Calcium silicate cements, including MTA, show a favorable biological response with the stimulation of mineralized tissue deposition in sealed areas when in contact with connective tissue. This is due to the similarity between the chemical elements, especially ionic dissociation, the potential stimulation of enzymes in tissues, and the contribution towards an alkaline environment due to the pH of these materials. The behavior of bioactive materials, especially MTA and the new calcium silicate cements in the biological sealing activity, has been shown to be effective. Contemporary endodontics has access to bioactive materials with similar properties, which can stimulate a biological seal in lateral and furcation root perforations, root-end fillings and root fillings, pulp capping, pulpotomy, apexification, and regenerative endodontic procedures, in addition to other clinical conditions.

Microbiological Properties and Cytotoxicity of PNVCL Hydrogels Containing Flavonoids as Intracanal Medication for Endodontic Therapy

This study aimed to evaluate the cytotoxicity and microbiological properties of poly (N-vinylcaprolactam)-PNVCL hydrogels containing flavonoids as intracanal medication for endodontic therapy. Antimicrobial activity of ampelopsin (AMP), isoquercitrin and rutin was determined against Enterococcus faecalis, Actinomyces israelii, Lactobacillus casei, Streptococcus mutans, and Fusobacterium nucleatum by the microdilution method. After synthesis and characterization by rheology, PNVCL hydrogels were loaded with AMP and controls calcium hydroxide (CH) and chlorhexidine (CHX), and determined the compounds release profile. PNVCL+AMP, PNVCL+CH, PNVCL+CHX were evaluated on multi-species biofilms and analyzed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Cytotoxicity was determined after fibroblasts exposure to serial dilutions of AMP and PNVCL hydrogel extracts. AMP was effective against all of the bacteria tested, especially against S. mutans, A. israelli and F. nucleatum. SEM and CLSM analysis showed that PNVCL + AMP caused a significant decrease and disorganization of multi-species biofilms and reduction of intracanal viable cells, superior to the other groups. AMP affected fibroblast viability at concentrations above 0.125 mg/mL, and extracts of PNVCL+AMP showed low cytotoxicity. In conclusion, PNVCL containing AMP demonstrated cytocompatibility and potent effect against multi-species biofilms and could be potential intracanal medication for endodontic purposes.

Comparative Evaluation of the Efficacy of Light-Cured Calcium Hydroxide and a Fourth-Generation Calcium Silicate Cement (TheraCal LC) as Indirect Pulp Capping Materials in Patients With Deep Carious Lesions: A Randomized Parallel-Group Clinical Trial

Aim

The current study aims to evaluate and compare the efficacy of light-cured calcium hydroxide and a fourth-generation calcium silicate cement (TheraCal LC®) as indirect pulp capping (IPC) materials in patients with deep carious lesions.

Materials and methods

A total of 28 patients were randomly divided into two groups (n=14). Group A was managed by light-cured calcium hydroxide, while group B was treated with TheraCal LC (a fourth-generation calcium silicate cement). Clinical examination was conducted to check for postoperative pain, tenderness, and neural sensibility, and radiographical examination was conducted to check for periodontal ligament space widening, presence of calcific barrier, and periapical radiolucency at patient recall of 21 days, three months, and six months. Primary and secondary outcome variables were based on clinical and radiographical success rates noted at six months’ follow-up.

Results

Success rate for light-cured calcium hydroxide group at follow-up came out to be 0% at 21 days, 85.71% at three months, and 92.85% at six months. The success rate for TheraCal LC group came out to be 0% at 21 days, 92.85% at three months, and 100% at six months. The overall success rate for IPC procedure was 89.28% at three months’ follow-up and 96.42% at six months’ follow-up for both groups. The difference was statistically non-significant at the end of three and six months’ follow-up.

Conclusion

Within the limitations of our study, it was concluded that TheraCal LC can be used alternatively with light-cured calcium hydroxide in IPC, with a predictability of similar success outcome in patients with deep carious lesions.

Evaluation of Antibacterial and Antifungal Effects of Calcium Hydroxide Mixed with Two Different Essential Oils

BACKGROUND

Calcium hydroxide is a routinely used material for root canal disinfection during root canal treatment. Natural products have great potential in terms of their antibacterial effects. This study aimed to establish an effective alternative intracanal medicament using Origanum dubium (O. dubium) and Mentha spicata (M. spicata) essential oils.

MATERIALS AND METHODS

O. dubium and M. spicata, collected from Lefke, Cyprus, were separately subjected to hydrodistillation. The obtained essential oil compositions were analysed simultaneously by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The compositions were then divided into groups and mixed with calcium hydroxide at a 1:1 concentration; after that, the pastes were tested on Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans), which are the most common resistant pathogenic microorganisms in the root canal. The antibacterial activity of the pastes was measured using a disk diffusion assay.

RESULTS

The GC and GC-MS analyses revealed that O. dubium and M. spicata had major compositions of carvacrol (75.8%) and carvone (71.3%), respectively. Antimicrobial activity was found to be significantly higher when study groups with O. dubium essential oil were applied to both E. faecalis and C. albicans. The results also show that M. spicata, together with calcium hydroxide, demonstrated a significant antifungal effect on C. albicans when incubated for 72 h.

CONCLUSIONS

M. spicata was found to be an effective antimicrobial agent on C. albicans, whereas O. dubium was found to be very effective on both E. faecalis and C. albicans. These data demonstrate that these natural essential oils may be promising candidates for alternative intracanal medicament in future routine clinical applications.

Local Drug Delivery Systems for Vital Pulp Therapy: A New Hope

Vital pulp therapy (VPT) is deliberated as an ultraconservative/minimally invasive approach for the conservation of vital pulpal tissues, preservation of dental structure, and maintenance of tooth function in the oral cavity. In VPT, following the exposure of the dental pulp, the environment is prepared for the possible healing and probable refunctionalisation of pulpal connective tissue. However, to succeed in VPT, specific biomaterials are used to cover and/or dress the exposed pulp, lower the inflammation, heal the dental pulp, provoke the remaining odontoblastic cells, and induce the formation of a hard tissue, i.e., the dentinal bridge. It can be assumed that if the employed biomaterial is transferred to the target site using a specially designed micro-/nanosized local drug delivery system (LDDS), the biomaterial would be placed in closer proximity to the connective tissue, may be released in a controlled and sustained pattern, could properly conserve the remaining dental pulp and might appropriately enhance hard-tissue formation. Furthermore, the loaded LDDS could help VPT modalities to be more ultraconservative and may minimise the manipulation of the tooth structure as well as pulpal tissue, which could, in turn, result in better VPT outcomes.

Antibacterial Effect and Bioactivity of Innovative and Currently Used Intracanal Medicaments in Regenerative Endodontics

INTRODUCTION

The purpose of this study was to determine the antibacterial effect and bioactivity of triple antibiotic paste (TAP), calcium hydroxide (Ca[OH]₂), and calcium hypochlorite (Ca[OCl]₂).

METHODS

Root canals were infected with 3-week-old Enterococcus faecalis biofilm and then medicated for 7 days with TAP, Ca(OH)₂, or Ca(OCl)₂ (n = 10/group). Untreated and uninfected canals were used as positive and negative controls. The antibacterial effect was determined using colony-forming units and a Live/Dead bacterial viability kit. Dental pulp stem cells were seeded on medicated dentin surfaces for 7 days. Sodium thiosulfate and various concentrations of ascorbic acid (1%, 5%, and 10%) were also used to neutralize the samples treated with Ca(OCl)₂ before cell seeding (n = 3 in triplicate). Cell viability and morphology were evaluated using a viability assay and Live/Dead cell analysis. Alkaline phosphatase (ALP) activity was also measured to determine the cells' mineralization activity.

RESULTS

All medicaments decreased the initial bacterial load (P < .05). The highest bacterial reduction in the main canal and dentinal tubules was observed in the Ca(OCl)₂ group (P < .05). TAP- or Ca(OH)₂-treated dentin surface improved cell viability and ALP activity compared with the untreated dentin surface (P < .05), whereas Ca(OCl)₂ decreased cell viability and ALP activity (P < .05). Ten percent ascorbic acid neutralized the effect of Ca(OCl)₂ on the treated dentin surface, showing higher cell viability (P < .05) and similar ALP activity with the untreated dentin surface and the other groups (P > .05).

CONCLUSIONS

Ca(OCl)₂ medication improved root canal disinfection against E. faecalis biofilm compared with TAP and Ca(OH)₂. The adverse effects caused by Ca(OCl)₂ on cell viability and mineralization activity can be neutralized with 10% ascorbic acid.

Conservative Approach in the Management of Large Periapical Cyst-Like Lesions. A Report of Two Cases

Background and Objectives: Periapical cystic lesions are a pathology frequently addressed to endodontic specialists. Although their therapy is still not standardized, the treatment should be as conservative as possible and by endodontic means, as they are lesions of endodontic origin. The present case report describes two cases of upper central incisors with large cyst-like periapical lesions, and their one-year follow up. Materials and Methods: Endodontic orthograde treatment was performed under copious irrigation with sodium hypochlorite, in association with calcium hydroxide as an intra-canal medication for both teeth. Root canal filling was achieved in a separate appointment using the continuous wave of condensation technique. A decompression procedure was used in association with endodontic therapy in the second case to reduce the pressure inside the cystic lesion and to allow its drainage, and only because the root canal could not be dried three weeks after medication. Initial cone beam computed tomography (CBCT) investigations, as well as at the one-year follow up, were used to compare the evolution of the lesion. Results: Both cases had a favorable outcome. New bone formation in the periapical region and complete resolution of the lesion was observed at the one-year control in the first case. In the second case, although the lesion was still not completely healed at 12 months, a significant reduction in its size could be observed, showing active signs of healing. Conclusions: Endodontic treatment is the first choice option in the management of teeth with pulpal necrosis and large periapical cystic-like lesions. Decompression is the only surgical procedure recommended when the canals cannot be dried and obturated. Large surgical interventions are unnecessary in cases where endodontic treatment can be performed.

Clinical, radiographic, and histological evaluation of three different pulp-capping materials in indirect pulp treatment of primary teeth: a randomized clinical trial

OBJECTIVES

The aim of this randomized, controlled, three-arm parallel group, and double-blinded clinical trial was to evaluate the clinical, radiographic, and histopathological success of three different pulp-capping materials in one-stage indirect pulp treatment of primary teeth.

MATERIALS AND METHODS

The study included a total of 109 patients aged 5-9 years who had primary teeth with deep carious lesions and symptoms of reversible pulpitis. The teeth were divided into three groups according to the pulp-capping agents: (I) hard-setting calcium hydroxide (Dycal) (control group) (n = 36), (II) bioactive tricalcium silicate (Biodentine) (n = 37), and (III) resin-based tricalcium silicate (TheraCal LC) (n = 36). All the teeth were evaluated clinically and radiographically at 6, 12, 18, and 24 months postoperatively. A total of 23 primary mandibular second molars that were in their regular exfoliation period (24-40 months) were extracted and fixed in 10% formaldehyde solution. The specimens were evaluated histologically to assess the integrity of the odontoblastic layer, tertiary dentin formation quality of the dentin formed, severity of pulpitis, and other pulpal changes. Data were analyzed using Fisher's exact test, Pearson's chi-square test, and McNemar's test (p = 0.05).

RESULTS

At the end of the 24-month follow-up period, the clinical and radiographic success rates for Dycal, Biodentine, and TheraCal LC were 100%, 100%, and 93.3%, respectively, and there was no significant difference among the groups (p > 0.05). However, the TheraCal LC group was statistically unsuccessful when compared to the other groups with regard to the integrity of the odontoblastic layer, severity of pulpitis, and other pulpal changes in histological examination (p < 0.05).

CONCLUSION

Indirect pulp capping exhibited high clinical and radiographic success rates in the treatment of primary teeth regardless of the chosen pulp-capping agent. However, histological examination indicated that the pulp status was affected by the chosen capping material especially when selecting a resin-containing material such as TheraCal LC.

CLINICAL RELEVANCE

Resin-free calcium silicate-based materials appear to be more favorable in the indirect pulp treatment of primary teeth, particularly in young-age groups that require long-term success.

Bacterial levels and amount of endotoxins in carious dentin within reversible pulpitis scenarios

OBJECTIVES

the objective of the present exploratory study was to determine bacterial diversity and endotoxin levels in deep carious lesions of teeth presenting symptoms of reversible pulpitis.

MATERIALS AND METHODS

Twenty patients with deep carious lesions, reporting clinical symptomatology compatible with reversible pulpitis (n = 10) or not reporting clinical symptomatology (n = 10), were selected. Carious dentin samples were obtained with the aid of sterile and pyrogen-free spoon excavators and harvested in two steps: before and after infected dentin removal. Samples were collected for checkerboard and for kinetic chromogenic LAL assay for determination of microbial profile and quantitation of endotoxin, respectively. Data were analyzed by Mann Whitney for bacteria and two-way ANOVA for endotoxins (5%).

RESULTS

No difference on the studied bacteria was detected between the superficial and deep dentin layers. Symptomatic teeth showed greater presence of Lactobacillus species, Capnocytophaga sputigena, and Leptotrichia buccalis. For the endotoxins, symptomatic teeth resulted in greater quantity of endotoxins (p = 0.047), being 4.13 log₁₀ EU/mL/μg dentin and 3.45 log10 EU/mL/μg dentin, for symptomatic and asymptomatic teeth, respectively. Dentin collected in different areas presented similar number of endotoxins (p = 0.139).

CONCLUSION

The amount of the studied bacteria does not seem to be related to reported symptomatology of deep carious lesions, while endotoxins quantity is greater in symptomatic scenarios, regardless of the harvesting area.

CLINICAL RELEVANCE

The understanding of bacterial amount in reversible pulpitis is important to establish a clinical protocol of treatment.

In vivo Study of Sealing Capability of Raw Propolis Extract and Calcium Hydroxide on Dentin Surface

Aim

This research aimed to investigate the differences in the sealing capability of propolis extracts and Ca(OH)₂ on dentin surfaces.

Materials and Methods

Eighteen mandible incisors of Wistar rats were prepared at a depth of 0.5 mm after which they were randomly divided into 3 groups (n=6) including control (C), pulp-capped with Ca(OH)₂ group (P1), and indirect pulp-capped with propolis extract group (P2). All the cavities were sealed with glass ionomer restorative cement. Moreover, the sections of the teeth were obtained after six Wistar Rats from each group were sacrificed on the second day after treatment. The rats’ incisors were cleaved transversally to the area where Ca(OH)₂ and propolis extract bonded with dentin for the SEM (scanning electron microscope) analysis and examined using microphotographs test with 5000x magnification. All the samples were measured and examined with spectrophotometry test to determine the bonding distance between Ca(OH)₂ and dentin, as well as propolis extract and dentin. The result from the two tests was analyzed with SPSS using an independent t-test at p <0.05.

Results

There were significant differences between the calcium hydroxide and propolis extract groups (p<0.05) based on the results obtained in the form of spectrums chemical functional groups of spectrophotometry examination. No new chemical bonding or compound was also observed to have been formed between propolis extract with dentin as well as calcium hydroxide with dentin.

Conclusion

The adaptation or sealing capability of propolis extract was found to be better than calcium hydroxide to the dentin surface.

Mineral trioxide aggregate (MTA) inhibits osteoclastogenesis and osteoclast activation through calcium and aluminum activities

OBJECTIVE

To evaluate the effect(s) of mineral trioxide aggregate (MTA) on in vitro RANKL-mediated osteoclast-dependent bone resorption events and the influence of Ca²⁺ and Al³⁺ on the osteoclastogenesis inhibition by MTA.

MATERIALS AND METHODS

Two types of osteoclast precursors, RAW 264.7 (RAW) cell line or bone marrow cells (obtained from BALB/c mice and stimulated with recombinant (r) macrophage colony stimulation factor (M-CSF), were stimulated with or without recombinant (r) activator of nuclear kappa B ligand (RANKL), in the presence or absence of MTA for 6 to 8 days. White Angelus MTA and Bios MTA (Angelus, Londrina, Paraná, Brazil) were prepared and inserted into capillary tubes (direct contact surface = 0.50 mm² and 0.01 mm²). Influence of MTA on these types of osteoclast precursors was measured by the number of differentiated tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (RAW and bone marrow cells), TRAP enzyme activity (RAW cells), cathepsin K gene expression (RAW cells), and resorptive pit formation (RAW cells) by mature osteoclasts. Besides, RAW cells were also stimulated with Ca²⁺ and Al³⁺ to evaluate the influence of these ions on MTA anti-osteoclastogenic potential.

RESULTS

In bone marrow and RAW cells, the number of TRAP-positive mature osteoclast cells induced by rRANKL was significantly inhibited by the presence of MTA compared with control rRANKL stimulation without MTA (p < 0.05), along with the reduction of TRAP enzyme activity (p < 0.05) and the low expression of cathepsin K gene (p < 0.05). In contrast, to control mature osteoclasts, the resorption area on dentin was significantly decreased for mature osteoclasts incubated with MTA (p < 0.05). rRANKL-stimulated RAW cells treated with Ca²⁺ and Al³⁺ decreased the number of osteoclasts cells. Besides, the aluminum oxide was the dominant suppressor of the osteoclastogenesis process.

CONCLUSIONS

MTA significantly suppressed RANKL-mediated osteoclastogenesis and osteoclast activity and, therefore, appears able to suppress bone resorption events in periapical lesions. This process might be related to Ca²⁺ and Al³⁺ activities.

CLINICAL RELEVANCE

MTA is an important worldwidely acknowleged biomaterial. The knowledge about its molecular activities on osteoclasts might contribute to improving the understanding of its clinical efficacy.

Mineralization-inducing potentials of calcium silicate-based pulp capping materials in human dental pulp cells

Background

This study was performed to provide a long-term bacterial seal through the formation of reparative dentin bridge, calcium silicate-based pulp capping materials have been used at sites of pulpal exposure. The aim of this study was to evaluate the mineralization-inducing potentials of calcium silicate-based pulp capping materials (ProRoot MTA [PR], Biodentine [BD], and TheraCal LC [TC]) in human dental pulp cells (HDPCs).

Methods

Specimens of test materials were placed in deionized water for various incubation times to measure the pH variation and the concentration of calcium released. The morphology of HDPCs cultured on the specimens was examined using a confocal laser scanning microscope (CLSM). Alizarin red S staining and alkaline phosphatase assays were used to evaluate mineralization-inducing potentials of the capping materials.

Results

BD showed the highest calcium release in all test periods, followed by PR and TC. (p<0.05). All experimental groups showed high alkalinity after 1 day, except at 14 days. BD showed the highest cell viability compared with PR and TC after 1 and 3 days, while TC showed the lowest value (p<0.05). The CLSM analysis showed that cells were well adhered and expressed actin filaments for all pulp capping materials. Mineralization by PR and BD groups was higher than that by TC group based on alizarin red S staining. BD showed significantly higher alkaline phosphatase activity than PR and TC, while TC showed the lowest value (p<0.05).

Conclusion

Within the limitations of the in vitro study, BD had higher mineralization-inducing potential than PR and TC.

Comparison of shear bond strength of light cure mineral trioxide aggregate and light cure calcium hydroxide with nanofilled composite: A stereomicroscopic and scanning electron microscope analysis

OBJECTIVE

The quest for ideal pulp capping materials has given rise to the development of newer materials such as light cure mineral trioxide aggregate (MTA). The bond strength of the pulp capping materials with overlying restoration is one among the several factors that are critical for the success of vital pulp therapy. Hence, we conducted this study to evaluate and compare the shear bond strength (SBS) of light cure MTA and light cure calcium hydroxide with nanofilled composite.

MATERIALS AND METHODS

Thirty acrylic blocks each with a central hole were prepared to uniform dimensions and randomly distributed into two equal groups. In Group I, light cure MTA, and in Group II, light cure calcium hydroxide was used as pulp capping materials. After the application of adhesive system, nanofilled composites were applied onto the pulp capping material using a cylindrical plastic matrix. The SBS was tested on a universal testing machine (Instrom 3366, UK) at a crosshead speed of 0.5 mm/min. The samples were examined under stereomicroscope and scanning electron microscope to analyze different modes of failure.

RESULTS

The results were statistically analyzed using independent sample t-test. Light cure MTA attained the mean SBS of 6.54 MPa and light cure calcium hydroxide attained the mean SBS of 6.56 MPa. There was no significant difference statistically in SBS of both the materials (P < 0.05). The modes of failure were predominantly mixed failure followed by cohesive failure within the restorative material in both Group I and II.

CONCLUSION

The results of the study suggest that the SBS of light cure MTA and light cure calcium hydroxide is comparable. The modes of failure analyzed in both light cure MTA and light cure calcium hydroxide are not significantly different statistically. Hence, both materials can be successfully used as pulp capping material with nanofilled composite.

Calcium release and physical properties of modified carbonate apatite cement as pulp capping agent in dental application

Background

Carbonate apatite (CO₃Ap) and silica-calcium phosphate composite (SCPC) are bone substitutes with good prospect for dental application. SCPC creates a hydroxyapatite surface layer and stimulate bone cell function while, CO₃Ap induce apatite crystal formation with good adaptation providing good seal between cement and the bone. Together, these materials will add favorable properties as a pulp capping material to stimulate mineral barrier and maintain pulp vitality. The aim of this study is to investigate modification of CO₃Ap cement combined with SCPC, later term as CO₃Ap-SCPC cement (CAS) in means of its chemical (Calcium release) and physical properties (setting time, DTS and pH value).

Methods

The study consist of three groups; group 1 (100% calcium hydroxide, group 2 CO₃Ap (60% DCPA: 40% vaterite, and group 3 CAS (60% DCPA: 20% vaterite: 20% SCPC. Distilled water was employed as a solution for group 1, and 0.2 mol/L Na₃PO₄ used for group 2 and group 3.

Samples were evaluated with respect to important properties for pulp capping application such as pH, setting time, mechanical strength and calcium release evaluation.

Results

The fastest setting time was in CO₃Ap cement group without SCPC, while the addition of 20% SCPC slightly increase the pH value but did not improved the cement mechanical strength, however, the mechanical strength of both CO₃Ap groups were significantly higher than calcium hydroxide. All three groups released calcium ions and had alkaline pH. Highest pH level, as well as calcium released level, was in the control group.

Conclusion

The CAS cement had good mechanical and acceptable chemical properties for pulp capping application compared to calcium hydroxide as a gold standard. However, improvements and in vivo studies are to be carried out with the further development of this material.

Application of Calcium Silicate Materials After Acid Etching May Preserve Resin-Dentin Bonds

INTRODUCTION

The aim of the present study was to evaluate the effect of the application of calcium silicate materials (CSMs), after acid etching, on the longevity of the hybrid layer and marginal adaptation of composite restorations.

METHODS AND MATERIALS

Eighty human permanent molars received an intrapulpal pressure of 15 cm H₂O. Sixty teeth received a mesial proximal slot preparation with the gingival margin extending 1 mm below the cemento-enamel junction. The samples were divided into two groups. Group 1 received restorations using two types of etch-and-rinse adhesives: ethanol based (Single Bond, 3M ESPE, St Paul, MN, USA) and acetone based (Prime & Bond NT, Dentsply, DeTrey GmbH, Germany). In group 2 samples, a commercially available CSM (ProRoot MTA) was allowed to set before grinding and placing into a distilled water solution. This solution was applied on the cavity floor after acid etching. The surface was washed after 30 seconds followed by application of adhesives and restorations as in group 1. The samples were stored in phosphate-buffered saline for six months, maintaining the intrapulpal pressure. An epoxy replica was made, and the marginal adaptation was evaluated using scanning electron microscopy. The percentage of continuous margin (CM) was recorded for each group. Another 20 samples were used for hybrid layer evaluation. The crowns were ground to expose dentin. Intrapulpal pressure was applied. The samples were divided into two groups and restored similar to samples restored for marginal adaptation evaluation. The samples were longitudinally cut in 1-mm slices. The slices were stored under 15 cm of phosphate-buffered saline to simulate the pulpal pressure. After six months, the adhesive interface was evaluated using a scanning electron microscope. Statistical analysis was done with two-way analysis of variance with Holm-Sidak's correction for multiple comparisons.

RESULTS

Application of CSMs improved the marginal adaptation values in both adhesive groups. In group 1, there were areas of incomplete penetration of resins along with evidence of partial degradation of resin tags. Samples receiving CSM application after acid etching demonstrated long and regular resin tags with very few signs of degradation.

CONCLUSIONS

Application of CSMs after acid etching can be a potential avenue in preserving the resin-dentin bonds.

Immediate tooth replantation: root canal filling for delayed initiation of endodontic treatment

The aim of this study is to evaluate the action of paramonochlorophenol associated with Furacin followed by calcium hydroxide (CH) dressing in the control of inflammatory root resorption in cases of immediate tooth replantation with delayed endodontic treatment. A total of 28 incisors of 3 male dogs were extracted and replanted after 15 minutes, and randomly divided into 3 groups: Group I (n = 8) - endodontic treatment was performed before the extraction and replantation; Group II (n = 10) - endodontic treatment was performed 30 days after replantation and the root canal was filled with CH dressing; Group III (n = 10) - endodontic treatment was performed 30 days after replantation and root canals received temporary medication of paramonochlorophenol-Furacin followed by CH dressing. The animals were euthanized 90 days after replantation. The histomorphological events analyzed at the epithelial reattachment site were the intensity and extent of acute and chronic inflammatory processes, periodontal ligament (PDL) organization, the intensity and extent of acute and chronic inflammatory processes in the PDL space, root resorption, bone tissue, and ankylosis. Data were submitted to the Wilcoxon Signed Ranks Test for group comparison (α = 5%). In Groups I, II and III the periodontal ligament was regenerated and most of the resorption areas were repaired by newly formed cementum. The depth and extent of root resorption were significantly higher in Group II than in Group III. The use of paramonochlorophenol-furacin followed by CH dressing was more effective in controlling inflammatory root resorption after immediate tooth replantation.

Management of Cyst-like Periapical Lesions by Orthograde Decompression and Long-term Calcium Hydroxide/Chlorhexidine Intracanal Dressing: A Case Series

Cyst-like periapical lesions should be treated initially with conservative nonsurgical procedures. In this case series, we describe the clinical and radiographic outcomes of large cyst-like lesions that were treated by orthograde decompression and long-term intracanal use of calcium hydroxide [Ca(OH)2] mixed with 2% chlorhexidine digluconate. Ten cases of cyst-like periapical lesions involving 15 teeth from 10 patients were selected. Maximal radiographic diameters of the lesions ranged from 11 to 28 mm. Nonsurgical procedures were performed, including apical patency, orthograde puncture of cyst-like exudates, chemomechanical preparation, and placement of intracanal Ca(OH)2/CHX dressings, which were periodically replaced during 6-10 months. The root canals were then filled with gutta-percha and sealer. The follow-up periods ranged from 6 to 24 months, and the outcome was classified as healed, healing, or failure. Nine lesions drained copious exudates after canal patency. One lesion only drained bloody serous exudate after periapical overinstrumentation. In 9 patients, intracanal exudation ceased in the first follow-up visit. At the 24-month follow-up, 6 lesions (60.0%) had healed, and 3 lesions (30.0%) were healing, with the corresponding patients being without clinical signs or symptoms. The case of treatment failure was submitted to surgical treatment. Microscopically, the lesion appeared to be an apical cyst with exuberant extraradicular bacterial biofilms attached to the sectioned root apex. This case series supports the use of nonsurgical methods to resolve larger cyst-like periapical lesions.

Calcium hydroxide liners: a literature review

OBJECTIVE

This review integrates the literature on cavity liners and current concepts of pulp protection with the aim of establishing a better understanding of the role of calcium hydroxide as a cavity liner.

MATERIALS AND METHODS

A search was conducted through PubMed, MEDLINE, and Ovid for articles with the criteria for the following terms: cavity liners and bases, pulp protection, and calcium hydroxide liners. No specific inclusion or exclusion criteria were applied as to what articles would be included in this review. It was hoped that the extent of the literature reviewed would be as comprehensive as possible.

CONCLUSION

This review underlines the fact that calcium hydroxide liners should only be used in the deepest spots in the cavity where the remaining dentine thickness is ≤0.5 mm. A protective layer of resin-modified glass ionomer should always follow the application of calcium hydroxide liners.

Characterization of Chlorhexidine-Loaded Calcium-Hydroxide Microparticles as a Potential Dental Pulp-Capping Material

This study explores the delivery of novel calcium hydroxide [Ca(OH)₂] microparticles loaded with chlorhexidine (CHX) for potential dental therapeutic and preventive applications. Herein, we introduce a new approach for drug-delivery to deep dentin-surfaces in the form of drug-loaded microparticles. Unloaded Ca(OH)₂ [Ca(OH)₂/Blank] and CHX-loaded/Ca(OH)₂ microparticles were fabricated by aqueous chemical-precipitation technique. The synthesized-microparticles were characterized in vitro for determination of surface-morphology, crystalline-features and thermal-properties examined by energy-dispersive X-ray scanning and transmission electron-microscopy (EDX-SEM/TEM), Fourier-transform infrared-spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning-calorimetry (DSC). Time-related pH changes, initial antibacterial/biofilm-abilities and cytotoxicity of CHX-loaded/Ca(OH)₂ microparticles were evaluated. Microparticles were delivered to dentin-surfaces with subsequent SEM examination of treated dentin-substrates. The in vitro and ex vivo CHX-release profiles were characterized. Ca(OH)₂/Blank were hexagonal-shaped with highest z-average diameter whereas CHX-inclusion evidenced micro-metric spheres with distinguishable surface “rounded deposits” and a negative-shift in diameter. CHX:Ca(OH)₂/50 mg exhibited maximum encapsulation-efficiency with good antibacterial and cytocompatible properties. SEM examination revealed an intact layer of microparticles on exposed dentin-surfaces with retention of spherical shape and smooth texture. Microparticles loaded on dentin-surfaces showed prolonged release of CHX indicating substantial retention on dentin-substrates. This study validated the inherent-applicability of this novel drug-delivery approach to dentin-surfaces using micro-metric CHX-loaded/Ca(OH)₂ microparticles.

A Comparative Study of Ion Diffusion from Calcium Hydroxide with Various Herbal Pastes through Dentin

AIM

The aim of this study was to evaluate the diffusion ability of ions through dentinal tubules of different nonalcoholic calcium hydroxide-containing herbal pastes and compare it with the calcium hydroxide paste prepared with saline.

MATERIALS AND METHODS

A total of 36 single-rooted premolar teeth were used in this study. The tooth crowns were removed and the root canals were prepared. Depending on the vehicle to be used for preparing calcium hydroxide pastes, six groups were made: Group I: Ca(OH)₂ saline paste (control group), group II: Ca(OH)₂ papaya latex paste, group III: Ca(OH)₂ coconut water paste, group IV: Ca(OH)₂ Ashwagandha (Withania somnifera) paste, group V: Ca(OH)₂ Tulsi (Ocimum tenuiflorum) paste, and group VI: Ca(OH)₂ garlic (Allium sativum) paste. After biomechanical preparation, calcium hydroxide herbal paste dressings were applied and sealed with resin-based cement. The teeth were placed in containers with deionized water, and the pH of the water was measured at regular intervals over 3, 24, 72, and 168 hours.

RESULTS

We observed that all herbal pastes allowed the diffusion of ions, but pastes prepared with Ashwagandha and papaya latex showed more ion diffusion after 168 hours and marked increase in pH, depicting better support for calcium hydroxide action.

CONCLUSION

We conclude that Ashwagandha and papaya latex allow better diffusion of calcium hydroxide through den-tinal tubules, thus enhancing its action, and advise its use as a vehicle for placing intracanal medicament.

HOW TO CITE THIS ARTICLE

Dausage P, Dhirawani RB, Marya J, Dhirawani V, Kumar V. A Comparative Study of Ion Diffusion from Calcium Hydroxide with Various Herbal Pastes through Dentin. Int J Clin Pediatr Dent 2017;10(1):41-44.

Evaluation of the bond strength of different adhesive agents to a resin-modified calcium silicate material (TheraCal LC)

This study evaluated the bond strength of different adhesive agents to TheraCal LC and mineral trioxide aggregate (MTA) and examined the morphologic changes of these materials with different surface treatments. A total of 120 specimens, 60 of MTA Angelus (AMTA), and 60 of TheraCal LC, were prepared and divided into six subgroups according to the adhesive agent used; these agents included Scotchbond Multipurpose, Clearfil SE Bond, Clearfil Protect Bond, Clearfil S³ Bond, OptiBond All-in-One, and G-aenial Bond. After application of adhesive agents, Filtek Z250 composite resin was placed onto the specimens. Shear bond strengths were measured using a universal testing machine, followed by examination of the fractured surfaces. The surface changes of the specimens were observed using scanning electron microscopy. Data were compared by two-way analysis of variance. Although no significant differences were found among the bond strengths of different adhesives to AMTA (p = 0.69), a significant difference was found in terms of bond strengths of different adhesives to the TheraCal LC surface (p < 0.001). The total-etch adhesive system more strongly bonded to TheraCal LC compared to the bond with other adhesives. TheraCal LC bonded significantly more strongly than AMTA regardless of the adhesive agents tested. Resin-modified calcium silicate showed higher bond strength than AMTA in terms of the composite bond to these materials with different bonding systems. On the other hand, the highest shear bond-strength values were found for composite bonds with the combination of TheraCal LC and the total-etch adhesive system. SCANNING 38:403-411, 2016. © 2015 Wiley Periodicals, Inc.

Dentin Cleaning Ability of an Amazon Bioactive: Evaluation by Scanning Electron Microscopy

The role of dentin cleaning is to remove debris that may impair adaptation and marginal sealing, quantitatively reducing microorganisms. The aim of this study was to investigate through scanning electron microscopy (SEM) the morphology of the dentin surface, cut and treated with copaiba oil emulsions (CO) and suspension of ethanol extract of propolis (EP). Twenty four upper pre-molars teeth, divided into eight groups (n=3), were used: G1: no cleaning, G2: air/water spray, G3: 10% CO, G4: 10% CO + A, G5: 30% CO, G6: 30% CO + A, G7: 1% EP, G8: 2% Chlorhexidine. The specimens were dentin discs (1 mm Ø). The SEM photomicrographs were classified and the results were: G1 - Debris dentin on the entire image / countless microorganisms, G2 and G7 - 50-100 debris / countless microorganisms and G3, G4, G5, G6 and G8 - 0-50 debris / countable microorganisms (50-100 colonies).

Strontium (Sr) elicits odontogenic differentiation of human dental pulp stem cells (hDPSCs): A therapeutic role for Sr in dentine repair?

Strontium (Sr) forms a significant component of dental restorative materials and although it is widely used in toothpastes, the biological effects of Sr on the dentine-pulp complex have not been investigated. In this first study, we characterise the Sr elicited effects on human dental pulp stem cells (hDPSC) in vitro using exogenously Sr added to culture medium, and bioavailable Sr derived from a novel bioactive glass (BG). The related mechanisms were also investigated. Our results indicate that low dose Sr (between 0.1 and 2.5mM) induces proliferation and alkaline phosphatase (ALP) activity of hDPSCs, but has no effect on colony formation or cell migration. Sr at specific concentrations (1 and 2.5mM) stimulated collagen formation and mineralisation of the hDPSC generated matrix. In addition, qRT-PCR, Western blotting and immunocytochemistry revealed that Sr regulates gene expression and the protein secretion of the odontogenic markers: dentine sialophosphoprotein (DSPP) and dentine matrix protein 1 (DMP-1) and protein localisation (DSPP was localised to the Golgi, while no apparent changes occur in DMP-1 distribution which remains in both cytosol and the nucleus). Additionally, the calcium sensing receptor (CaSR) and downstream pathway MAPK/ERK signalling pathway in hDPSCs were activated by Sr. Bioavailable Sr from the BG revealed novel biological insights of regulating metabolic and ALP activities in hDPSCs. Taken together, these results suggest that Sr at specific doses significantly influences proliferation, odontogenic differentiation and mineralisation of hDPSCs in vitro via the CaSR using a pathway with similarities to osteoblast differentiation. These are the first such studies and indicate that Sr treatment of hDPSCs could be a promising therapeutic agent in dental applications. In conclusion, we propose that Sr from a substituted BG could be used more effectively in biomaterials designed for dental applications.

STATEMENT OF SIGNIFICANCE

Despite the fact that strontium (Sr) is used widely in dental practise, its potential effects on odontoblasts have been ignored. Our study provides the first evidence that Sr (exogenous and that derived from a bioglass (BG)) can stimulate dentinogenesis in human dental pulp stem cells (hDPSCs) by promoting their proliferation, differentiation and mineralisation in vitro. Therefore, while previously unrecognised, Sr BG is likely to be beneficial in atraumatic dentistry practise and maintenance of a competent tooth in conditions such as caries. Repair of defected dentine is still one of the main challenges in dental research and annually untreated caries results in the loss of productivity equivalent to US$ 27 billion. Advances in tissue engineering technology, alongside the use of dental pulp stem cells provide an approach to achieve dentine regeneration. Understanding the actions of Sr will permit a more controlled application of Sr in the clinic. These data are thus likely to be of great interest to the material scientists, biological researchers, clinicians and manufacturers of dental products.

Characterization of successful root canal treatment

Knowing the outcome of root canal treatment (RCT) is determinant to substantiate the clinical decision making process, especially when RCT is weighed against the extraction of natural teeth or replacement by prosthetic elements. The ideal scenario in all clinical situations should combine healing/prevention of disease (apical periodontitis) and the functional retention of the tooth. Understanding the risk factors associated with endodontic failure is a key factor to increase the chances of success. The logical action is to reverse the existing disease, which requires intervention to neutralize the bacterial invasion and disrupt the bacterial biofilm within the complex anatomy. Success is more predictable when the immune host defenses are favorable. However, success has different meanings to the dentist, to the patient and to the tooth itself. The life of an endodontically treated tooth depends on the accuracy of the diagnosis and planning, excellence of disinfection, instrumentation and filling procedures (antimicrobial strategies, root canal shaping and coronal and apical seal) and finally the rehabilitation management. The interpretation of constant or intermittent pain and/or discomfort associated with apical periodontitis (AP) in endodontically treated tooth may be suggestive of endodontic failure. The success features of RCT, namely absence of pain, regression of AP, tight seal of canal and coronal spaces, and recovery of tooth function, must be reevaluated over time. In case of doubt between success and failure, cone beam computed tomography (CBCT) could be indicated for detection and precise localization of AP. The possibility of map reading on CBCT images characterizes the real multidimensional structure, providing accurate information on the presence, absence or regression of AP. The survival of an endodontically treated tooth implies understanding the biological and mechanical outcomes as multifactorial events over the individual's life span. The objective of this review of literature is to discuss relevant factors associated with patient's health, tooth and dentist that could account for a successful RCT.

To evaluate the biocompatibility of the Indian Portland cement with potential for use in dentistry: An animal study

Aims:

This study evaluated the biocompatibility of the Indian Portland cement with potential for use in dentistry.

Materials and Methods:

This study was performed in Swiss albino mice, by implanting the Indian Portland cement pellets subcutaneously. After 1, 3, and 6 weeks the tissue specimens were prepared for histological examination.

Results:

The histological analysis showed moderate to severe inflammation at 1 week. The inflammation gradually decreased by 6 weeks, with most of the specimens showing the absence of inflammatory reaction.

Conclusions:

According to these experimental conditions, the tested Indian Portland cement was biocompatible.

Apexification of an Immature Permanent Incisor with the Use of Calcium Hydroxide: 16-Year Follow-Up of a Case

Apexification is a process of forming a mineralized apical barrier and had been performed by using calcium hydroxide paste, due to its biological and healing performances in cases of existent trauma. This clinical report aims to report the results of a 16-year follow-up study of an apexification treatment applied to nonvital tooth 22 of a healthy 8-year-old male after a trauma. Clinical inspection of the tooth showed fractures of the incisal edge and mesial angle, absence of coronal mobility, and negative pulp vitality under cold testing. Radiographic analysis of the root revealed incomplete apex formation. The possibility of fracture into the root or luxation injury was rejected, and the diagnosis of pulp necrosis was verified. Apexification by calcium hydroxide and subsequent endodontic treatment were planned. Initial formation of the mineralized apical barrier was observed after 3 months, and the barrier was considered to be completed after 8 months. Clinical, radiographic, and CBCT examinations after 16 years verified the success of the treatment, although the choice of calcium hydroxide for apexification treatment is discussed.

Replantation as Treatment for Extrusive Luxation

In the treatment of extrusive luxation cases, it is important that the repositioning of extruded tooth in the socket is done as soon as possible. If this does not occur, periapical clot becomes organized and makes replantation difficult reposition. In this article the patient referred to the Clinics for dental trauma sustaining extrusive luxation of the maxillary right central incisor. The patient reported having suffered a bicycle accident 12 days before, which caused traumatic tooth injuries. The repositioning was attempted without success and an alternative form of treatment was necessary to solve the case. Intentional tooth replantation, which is the deliberate extraction of the tooth and its replantation, was indicated. This technique allows clot removal and correct repositioning of the extruded tooth. Care should be taken as endodontic treatment is required for the prevention of subsequent infection-related resorption. Intracanal dressing with calcium hydroxide was used for 30 days before final root filling. Splint, systemic antibiotics and avoidance of further damage to the root surface is also important. After 49 months, showed clinical and radiographic characteristics of normality and demonstrates the availability of this technique to adversity in trauma.

Calcium Silicate and Calcium Hydroxide Materials for Pulp Capping: Biointeractivity, Porosity, Solubility and Bioactivity of Current Formulations

Aim

The chemical-physical properties of novel and long-standing calcium silicate cements versus conventional pulp capping calcium hydroxide biomaterials were compared.

Methods

Calcium hydroxide–based (Calxyl, Dycal, Life, Lime-Lite) and calcium silicate–based (ProRoot MTA, MTA Angelus, MTA Plus, Biodentine, Tech Biosealer capping, TheraCal) biomaterials were examined. Calcium and hydroxyl ion release, water sorption, interconnected open pores, apparent porosity, solubility and apatite-forming ability in simulated body fluid were evaluated.

Results

All calcium silicate materials released more calcium. Tech Biosealer capping, MTA Plus gel and Biodentine showed the highest values of calcium release, while Lime-Lite the lowest. All the materials showed alkalizing activity except for Life and Lime-Lite. Calcium silicate materials showed high porosity values: Tech Biosealer capping, MTA Plus gel and MTA Angelus showed the highest values of porosity, water sorption and solubility, while TheraCal the lowest. The solubility of water-containing materials was higher and correlated with the liquid-to-powder ratio. Calcium phosphate (CaP) deposits were noted on materials surfaces after short aging times. Scant deposits were detected on Lime-Lite. A CaP coating composed of spherulites was detected on all calcium silicate materials and Dycal after 28 days. The thickness, continuity and Ca/P ratio differed markedly among the materials. MTA Plus showed the thickest coating, ProRoot MTA showed large spherulitic deposits, while TheraCal presented very small dense spherulites.

Conclusions

calcium silicate-based cements are biointeractive (ion-releasing) bioactive (apatite-forming) functional biomaterials. The high rate of calcium release and the fast formation of apatite may well explain the role of calcium silicate biomaterials as scaffold to induce new dentin bridge formation and clinical healing.

Effect of particle size on calcium release and elevation of pH of endodontic cements

BACKGROUND/AIM

Elevation of pH and calcium ion release are of great importance in antibacterial activity and the promotion of dental soft and hard tissue healing process. In this study, we evaluated the effect of particle size on the elevation of pH and the calcium ion release from calcium silicate-based dental cements.

MATERIAL AND METHODS

Twelve plastic tubes were divided into three groups, filled with white mineral trioxide aggregate (WMTA), WMTA plus 1% methylcellulose, and nano-modified WMTA (nano-WMTA), and placed inside flasks containing 10 ml of distilled water. The pH values were measured using a pH sensor 3, 24, 72, and 168 h after setting of the cements. The calcium ion release was measured using an atomic absorption spectrophotometer with same sample preparation method. Data were subjected to two-way analysis of variance (anova) followed by post hoc Tukey tests with significance level of P < 0.05.

RESULTS

Nano-WMTA showed significant pH elevation only after 24 h (P < 0.05) compared with WMTA, and after 3, 24, and 72 h compared with WMTA plus 1% methylcellulose (P < 0.05). Nano-WMTA showed significantly higher calcium ion release values compared to the other two groups (P < 0.05).

CONCLUSIONS

Nano-modification of WMTA remarkably increased the calcium ion release at all time intervals postsetting, which can significantly influence the osteogenic properties of human dental pulp cells and as a consequence enhance mineralized matrix nodule formation to achieve desirable clinical outcomes. However, the increase in pH values mainly occurred during the short time postsetting. Addition of 1% methylcellulose imposed a delay in elevation of pH and calcium ion release by WMTA.

Antimicrobial effect of calcium hydroxide as an intracanal medicament in root canal treatment: a literature review - Part I. In vitro studies

The goal of endodontic treatment is the prevention and control of pulpal and periradicular infections. Calcium hydroxide (Ca(OH)2) has been widely used in endodontics as an intracanal medicament to eliminate the remaining microorganisms after chemomechanical preparation. The purpose of this article is to review the antimicrobial properties of Ca(OH)2 as an intracanal medicament in root canal treatment. The first part of this review details the characteristics of Ca(OH)2 and summarizes the results of in vitro studies related to its antimicrobial effect. The antimicrobial effect of Ca(OH)2 results from the release of hydroxyl ions when it comes into contact with aqueous fluids. Ca(OH)2 has a wide range of antimicrobial effects against common endodontic pathogens, but is less effective against Enterococcus faecalis and Candida albicans. The addition of vehicles or other agents might contribute to the antimicrobial effect of Ca(OH)2.

Nonsurgical management of large periapical lesion in mature and immature teeth using different calcium hydroxide formulations: case series

This case series evaluates the effectiveness of different calcium hydroxide formulations with various vehicles in management of large periapical lesion in mature and immature teeth. This will help clinicians to make informed judgments about which formulations of calcium hydroxide should be used for specific endodontic procedures.

Simvastatin versus Calcium Hydroxide Direct Pulp Capping of Human Primary Molars: A Randomized Clinical Trial

Background and aims

The aim of present study was to investigate pulp-dentin complex reactions following direct pulp capping (DPC) with calcium hydroxide [Ca(OH)₂] and simvastatin as pulp-capping materials in the primary human molars.

Materials and methods

120 primary molar teeth which had to be extracted for orthodontic reasons were randomly allocated into four groups. Group Ι as a control, underwent DPC with calcium hydroxide. The dental pulp in group ІІ, ІІІ and ІV were directly capped with simvastatin-based materials at concentrations of 1, 5 and 10 µM, respectively. All of the teeth were restored with stainless steel crown. After a mean period of 7.41 months teeth were extracted and processed for histological examination and categorized in terms of hard tissue formation and pulp inflammation.

Results

Teeth in group I had statistically favorable outcomes in hard tissue formation and pulp inflammation than did the groups ІІ, ІІІ and ІV (P < 0.001). Considering three different concentrations of simvastatin, the result showed a dose dependent trend. Teeth in group ІV showed significantly lower rates of hard tissue formation and higher rates of pulp inflammation and necrosis compared to those of groups ІІ (P < 0.05).

Conclusion

The findings of this study depicted that healing with no inflammation and hard tissue formation following statin treatment occurs with a lower rate than that with the calcium hydroxide.

Assessment of ion diffusion from a calcium hydroxide-propolis paste through dentin

This study evaluated the ability of ions from a non-alcoholic calcium hydroxide-propolis paste to diffuse through dentinal tubules. Thirty-six single-rooted bovine teeth were used. The tooth crowns were removed, and the root canals were instrumented and divided into 3 groups: Group 1 - calcium hydroxide-propylene glycol paste; Group 2 - calcium hydroxide-saline solution paste; Group 3 - calcium hydroxide-propolis paste. After the root canal dressings were applied, the teeth were sealed and placed in containers with deionized water. The pH of the water was measured after 3, 24, 72 and 168 hours to determine the diffusion of calcium hydroxide ions through the dentinal tubules. All of the pastes studied promoted the diffusion of calcium hydroxide ions through the dentinal tubules. Associating propolis to calcium hydroxide resulted in a pH increase, which occurred with greater intensity after 72 hours. The calcium hydroxide-propolis paste was able to diffuse in dentin.

Estudo longitudinal do sucesso clínico-radiográfico de dentes tratados com medicação intracanal de hidróxido de cálcio

INTRODUÇÃO: O tratamento endodôntico é de fundamental importância para abolir a infecção presente em dentes que apresentam necrose pulpar. OBJETIVO: O objetivo do presente estudo foi avaliar clínica e radiograficamente a eficácia dos tratamentos de canais radiculares de dentes com lesão periapical crônica, efetuados pelos graduandos em Odontologia, da Faculdade de Odontologia de Araçatuba - UNESP. MATERIAL E MÉTODO: Foram selecionados 100 pacientes que possuíam dentes com lesão periapical crônica para serem tratados. Após o preparo biomecânico, os canais radiculares receberam uma medicação intracanal de hidróxido de cálcio durante o período de 14 dias. Os canais radiculares foram obturados com cimento endodôntico à base de hidróxido de cálcio. Foi realizada a proservação por um período entre oito e 11 meses. RESULTADO: A análise dos resultados permitiu constatar a porcentagem de 78,46% dos casos com reparo total da lesão periapical e de 21,54% dos casos em que não houve evidências de reparo. CONCLUSÃO: Ocorreu reparo das lesões periapicais nos dentes tratados pelos graduandos da Faculdade de Odontologia de Araçatuba - UNESP.

In vitro antimicrobial activity of root canal sealers and calcium hydroxide paste

AIM

To evaluate the in vitro antimicrobial activity of different root canal sealers and calcium hydroxide (CH) paste.

MATERIALS AND METHODS

The sample was composed of two sealers (Fill Canal(®) and Sealer 26(®)), one CH cement (Hydro C(®)), and a CH paste. The agar diffusion test was performed in Petri dishes inoculated with the following microorganisms: Streptococcus salivarius, Streptococcus oralis, Streptococcus mitis, Lactobacillus casei, Streptococcus mutans, Candida albicans, Candida krusei, and Candida tropicalis. The diameters of the zones of microbial growth inhibition were measured after 24 h. The tests were performed in triplicate. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level.

RESULTS

Fill Canal(®) exhibited the largest mean zone of microbial growth inhibition against the Candida species and differed significantly from the other groups (P < 0.001). When inhibition was observed against S. mitis and S. oralis, the CH paste presented a larger mean zone of microbial growth inhibition than those of the other materials (P < 0.05). Regarding the inhibition of S. mutans, a statistically significant difference was observed only between the CH paste and Hydro C(®) (P < 0.05); the paste produced the largest mean zone of microbial growth inhibition against this microorganism. Regarding the inhibition of S. salivarius, Fill Canal(®) presented smaller mean zone of microbial growth inhibition than Sealer 26(®) and CH paste (P < 0.05).

CONCLUSION

All the materials presented zones of microbial growth inhibition against all the test bacteria. Fill Canal(®) presented the largest mean zone of inhibition against the Candida species. For the Streptococcus cultures, none of the sealers presented inhibition superior to that of the CH paste.

Surface tension of calcium hydroxide associated with different substances

The purpose of this study was to evaluate the surface tension of calcium hydroxide (CH) associated with different substances (deionized distilled water, camphorated paramonochlorophenol, 2% chlorhexidine digluconate, Otosporin, 3% sodium lauryl ether sulphate; Furacin, PMC Furacin) using tensiometer. The action of the substances studied on the dentinal structure enhances the property of surface tension. This method consists in the application of force to separate a platinum ring immersed in the substances. Thus, torsion was applied to the screw until the platinum ring separated during substances testing. Considering the methodology applied, the following can be concluded: distilled water alone or associated with CH presented a high surface tension (70.00 and 68.40 dynes/cm); calcium hydroxide in association with anionic detergent showed low surface tension (31.60 dynes/cm); camphorated paramonochlorophenol plus CH presented low surface tension (37.50 dynes/cm); 2% chlorhexidine associated with calcium hydroxide showed high surface tension values (58.00 dynes/cm); Otosporin plus calcium hydroxide showed low surface tension (35.40 dynes/cm); paramonochlorophenol Furacin mixed with calcium hydroxide presented surface tension equal to 45.50 dynes/cm; sodium hypochlorite presented high surface tension (75.00 dynes/cm). Antimicrobial agents more indicated in endodontics, i.e. CH, chlorhexidine and hypochlorite, presented the highest surface tension.

Short-term vs long-term calcium hydroxide therapy after immediate tooth replantation: a histomorphometric study in monkey's teeth

Endodontic treatment is an important step of tooth replantation protocols, but the ideal moment for definitive obturation of replanted teeth has not yet been established. In this study, a histomorphometric analysis was undertaken to evaluate the repair process on immediate replantation of monkey's teeth after calcium hydroxide (CH) therapy for 1 and 6 months followed by root canal filling with a CH-based sealer (Sealapex(®) ). The maxillary and mandibular lateral incisors of five female Cebus apella monkeys were extracted, kept in sterile saline for 15 min, replanted and splinted with stainless steel orthodontic wire and composite resin for 10 days. In Group I (control), definitive root canal filling was performed before tooth extraction. In Groups II and III, CH therapy started after removal of splint, and definitive root canal filling was performed 1 and 6 months later, respectively. The animals were euthanized 9 months after replantation, and specimens were processed for histomorphometric analysis. In all groups, epithelial attachment occurred at the cementoenamel junction or very close to this region; the areas of resorption on root surface had small extension and depth and were repaired by newly formed cementum; and the periodontal ligament was organized. Statistical analysis of the scores obtained for the histomorphometric parameters did not show any statistically significant difference (P = 0.1221) among the groups. The results suggests that when endodontic treatment is initiated 10 days after immediate replantation and an antibiotic regimen is associated, definitive root canal filling can be performed after a short-term CH therapy.

An in vitro investigation of the mechanical-chemical and biological properties of calcium phosphate/calcium silicate/bismutite cement for dental pulp capping

The properties of new calcium phosphate/calcium silicate/bismutite (CPCSBi) cement were compared with those of calcium hydroxide (CH) and Dycal cements in dental pulp-capping applications. CPCSBi is composed of hydroxyapatite, tetracalcium phosphate, bismutite, and calcium silicate, which was analyzed by SEM, FTIR, and XRD. The results of ion release from CPCSBi showed that the concentrations of Bi(3+), Ca(2+), PO4(2-), and Si(4+) increased with time in deionized water solutions. The setting time of CPCSBi and Dycal was 13 min 50 s and 2 min 25 s, respectively. There were no statistical differences in compressive strength and solubility between CPCSBi and Dycal (p > 0.05). The pH of CPCSBi (10.9) was lower than that of CH (11.6) and Dycal (12.5) after immersion for 24 h. Only slight cytotoxicity appeared for CPCSBi, whereas both CH and Dycal produced moderate discoloration and lysis. In antimicrobial tests against Sm, Av, La, and Sa, the antimicrobial potency of the CPCSBi was approximately 5-10 times greater than that of Dycal and CH groups. The dissoluble dentin matrix components (DDMCs) extracted from CPCSBi exposed to dentin powder demonstrated increased expression of dentin sialophosphoprotein (DSPP) and soteocalcin (OCN) dramatically in human pulp cells by RT-PCR. These results suggest that CPCSBi will be a good candidate for use as a dental pulp-capping agent in future.