The Effect of Calcium Hydroxide Pastes on Isolated Vital Nerve Fibers.

INTRODUCTION: Calcium hydroxide pastes (CHPs), commonly used for disinfecting root canals during endodontic treatment, are generally considered safe. However, accidental extrusions result in minimal injuries and little to no discomfort, except when extruded pastes come into contact with nerve bundles, such as the inferior alveolar nerve. Currently, there is a lack of information about the possible role of specific paste vehicles on the extent of nerve injury. The purpose of this study was to compare the role that paste vehicles, such as water or methylcellulose, may play when nerve fibers are exposed to CHP. METHODS: Isolated sciatic nerves of Sprague-Dawley rats were exposed to either water-based or methylcellulose-based CHP for varying durations of time (30, 60, or 90 minutes). Histopathological changes, including axonal edema, myelin alterations, and loss of cellular outlines, were assessed, and the degrees of changes were compared using chi-square intraclass correlation coefficient tests. RESULTS: Both groups exposed to the pastes demonstrated varying degrees of histopathologic changes, including axonal edema, myelin changes, and loss of cellular outlines, at different exposure times. The water-based calcium hydroxide paste induced these changes more rapidly than the methylcellulose-based paste. Similar patterns were observed in the scanning electron microscopic findings. Exposure time emerged as an important difference in the effects of the 2 pastes. In each of these tests, all observations of water-based paste exposure were rated as moderate to severe, whereas the observed cellular changes (axonal, myelin, and intact cellular outline) were rated as mild to moderate after exposure to methylcellulose-based paste for the same exposure durations. The chi-square tests indicated a statistically significant association between the material and each of the outcomes (axonal changes: χ²15 = 81.0, P < .001; myelin changes: χ²15 = 81.0, P < .001; intact cellular outline, χ²15 = 81.0, P < .001). The intraclass correlation coefficient value was 0.93. CONCLUSIONS: The study demonstrates that axonal and myelin damage increase with longer exposure times, with water-based CHP causing more damage than methylcellulose-based CHP at each time point.

Inferior alveolar nerve injury due to the extrusion of calcium hydroxide during endodontic treatment: A case report.

Although many materials are used for root canal fillings in endodontic treatment, calcium hydroxide has been preferred for many years due to its bactericidal effect and biocompatibility. Calcium hydroxide can be applied in more than one form. In this case study, calcium hydroxide in viscous form, applied into the root canal during endodontic treatment, overflowed from the apical part of the tooth to the inferior alveolar nerve canal. Postoperative paraesthesia was observed in the patient. Dental volumetric tomography was performed to study the extent of sealer in the inferior alveolar nerve canal. Considering the short resorption time of the calcium hydroxide paste, no surgical intervention was performed on the patient. After 6 months, the root canal material was completely resorbed, and paraesthesia decreased. At the 3-year follow-up, the patient's paraesthesia had completely disappeared.

Legal Liability of a Dentist: Inferior Alveolar Nerve Damage After Calcium Hydroxide Extrusion.

ABSTRACT: During root canal treatments, calcium hydroxide can extrude through the apex causing chemical, mechanical, and/or thermal injuries to the inferior alveolar nerve, which can lead to neurological disorders. unfortunately, dental practitioner negligence can produce this potentially life-changing injury that can compromise the patient's life. The aim of this study is present a case of dental negligence by calcium hydroxide extrusion causing inferior alveolar nerve damage, discuss the methods of prevention, and characterize the medico-legal aspects of complication.

Comparison of calcium hydroxide extrusion with syringe versus spiral filler delivery: A pilot study.

This study aimed to evaluate Ca(OH)2 extrusion in relation to delivery technique, apical size and depth of placement. Plastic blocks had j-shaped canals shaped to apical sizes #35 and #45 (n = 32 each). Amounts of calcium hydroxide extrusion was determined relative to apical taper, depth of insertion and whether syringe or spiral filler at 500 rpm was used. Blocks were immersed in pH-sensitive gel and observed for colour change. Extent of extrusion was expressed in mm2 . Extrusion occurred in 48/64 of the samples. At 3 mm from the canal terminus, the device affected the frequency of extrusion, with syringe placement causing extrusion significantly (P < 0.01) more frequently, irrespective of apical size. Extrusion was significantly greater at 2 mm short of the canal terminus (median 27.44 mm2 ) compared to 3 mm (median 19.69 mm2 ). Under in-vitro conditions, a spiral filler at 500 rpm, 3 mm short of the apex, minimised extrusion of Ca(OH)2 from root canals.

Outcome Assessment of Teeth with Necrotic Pulps and Apical Periodontitis Treated with Long-term Calcium Hydroxide.

INTRODUCTION: The aim of this retrospective, cohort case series was 2-fold: (1) to evaluate the outcomes of teeth with necrotic pulps and apical periodontitis using long-term calcium hydroxide (Ca[OH]2) (healing was assessed via the periapical index [PAI] system) and (2) to explore the possible association of fractures in relation to long term Ca(OH)2 exposure. METHODS: A total of 242 cases, diagnosed with pulpal necrosis and apical periodontitis, were treated with long-term Ca(OH)2 using a standardized protocol. Injectable and powdered Ca(OH)2 were placed sequentially in the root canal system. All cases were re-evaluated within a 3-month period until radiographic healing was observed. Clinical and radiographic evaluations were performed annually. Pre- and postoperative periapical radiographs were evaluated using the PAI system. RESULTS: Of the 242 cases, 219 participants completed their treatment with annual follow-up. The average Ca(OH)2 time was 5.4 months with a range of 1-12 months. Overall, by the latest follow-up visit, 90.0% (197/219) were classified as "healed." The overall mean preoperative and postoperative PAI scores were 4.07 (±0.80) and 1.76 (±0.70), respectively. Kappa statistics showed an almost perfect agreement for inter-rater (κ = 0.91) and intrarater (κ = 0.95) reproducibility for both examiners. CONCLUSIONS: Within the limitations of this study, the use of long-term Ca(OH)2 in the treatment of teeth with necrotic pulps and apical periodontitis resulted in a predictable high outcome. There was no association observed between long-term Ca(OH)2 use and the incidence of fractures during this study. Ca(OH)2 is a suitable material of choice as an interappointment dressing for teeth diagnosed with pulpal necrosis and apical periodontitis.

Carbon Dioxide Absorption During Inhalation Anesthesia: A Modern Practice.

CO2 absorbents were introduced into anesthesia practice in 1924 and are essential when using a circle system to minimize waste by reducing fresh gas flow to allow exhaled anesthetic agents to be rebreathed. For many years, absorbent formulations consisted of calcium hydroxide combined with strong bases like sodium and potassium hydroxide. When Sevoflurane and Desflurane were introduced, the potential for toxicity (compound A and CO, respectively) due to the interaction of these agents with absorbents became apparent. Studies demonstrated that strong bases added to calcium hydroxide were the cause of the toxicity, but that by eliminating potassium hydroxide and reducing the concentration of sodium hydroxide to <2%, compound A and CO production is no longer a concern. As a result, CO2 absorbents have been developed that contain little or no sodium hydroxide. These CO2 absorbent formulations can be used safely to minimize anesthetic waste by reducing fresh gas flow to approach closed-circuit conditions. Although absorbent formulations have been improved, practices persist that result in unnecessary waste of both anesthetic agents and absorbents. While CO2 absorbents may seem like a commodity item, differences in CO2 absorbent formulations can translate into significant performance differences, and the choice of absorbent should not be based on unit price alone. A modern practice of inhalation anesthesia utilizing a circle system to greatest effect requires reducing fresh gas flow to approach closed-circuit conditions, thoughtful selection of CO2 absorbent, and changing absorbents based on inspired CO2.

Combined effects of calcium hydroxide and photobiomodulation therapy on apexogenesis of immature permanent teeth in dogs.

Treatment of high-risk traumatic immature teeth due to incomplete root development is challenging. Apexogenesis is currently the ideal treatment option that allows normal root development. The purpose of this study was to evaluate the apexogenesis process of immature permanent teeth of dogs when co-administered with calcium hydroxide and photobiomodulation therapy (PBMT). A total of 36 immature permanent anterior and premolar teeth were selected from three 4-6-month-old dogs of Iranian mixed generation. The teeth were categorized into two groups, calcium hydroxide with laser irradiation (CHL) and calcium hydroxide without laser irradiation (CH). All the selected teeth received calcium hydroxide pulpotomy. After restoring teeth with amalgam, the CHL group received gallium­aluminum-arsenide (GaAlAs) diode laser (810 nm, 4.2 J/cm2, 0.3 W, 9 s,CW) on apical one-third of both buccal and lingual roots. The irradiation was repeated every 48 h for fourteen days. Intravenous tetracycline was used to observe newly formed dentin in the first, third, seventh, and fourteenth days. The distance between tetracycline lines (DTL) was examined by Fluorescence microscopy. Generalized estimating equations (GEE) were used for data analysis. In all assessments, the mean DTL were greater in the CHL group. However, the two groups had no significant differences in the amount of deposited dentin between the first and third, third and seventh, and first and seventh lines. Meanwhile, there was a significant difference between the two groups in terms of the distances between lines 7 and 14, 1 and 14 and also 3 to 14 (P < .001). In other words, from the 7th day onwards, there was a significant difference between the two groups. Within the limitation of this study, the combination therapy of PBMT and pulpotomy with calcium hydroxide accelerated apexogenesis in immature permanent dogs' teeth.

Removal of Calcium Hydroxide from Artificial Grooves in Straight Root Canals: Sonic Activation Using EDDY Versus Passive Ultrasonic Irrigation and XPendo Finisher.

INTRODUCTION: The aim of the present study was to compare sonic activation using EDDY (VDW, Munich, Germany), passive ultrasonic irrigation (PUI), and mechanical activation using the XPendo Finisher (FKG Dentaire, La Chaux-des-Fonds, Switzerland) for the removal of calcium hydroxide from artificial grooves in straight root canals. METHODS: The root canals of 90 human maxillary incisors with straight root canals were prepared using Mtwo files (VDW) up to size 40/.04, and the teeth were split longitudinally. A lateral groove in the apical or coronal part was prepared in each root half and filled with calcium hydroxide, and the root halves were reassembled. Five groups were established according to the removal techniques: group A, the XPendo Finisher; group B, EDDY; group C, PUI; group D, manual irrigation with a syringe; and group E, no irrigation (the control group). The activation procedures were performed for 30 seconds with 3 mL sodium hypochlorite 3% as the irrigant. The cleanliness of the grooves was scored under 10× magnification. The median of scoring was analyzed using the Kruskal-Wallis test (P = .05). RESULTS: All activation techniques were significantly more effective in the removal of calcium hydroxide than manual irrigation (P < .05). Regarding the apical groove, EDDY and PUI were significantly more effective in the removal of calcium hydroxide than the XPendo Finisher (P < .05). No difference was found for the coronal groove (P > .05). CONCLUSIONS: EDDY and PUI were significantly more effective in the removal of calcium hydroxide than the XPendo Finisher regarding the apical region. Manual irrigation was significantly less effective than all activation techniques.

Consumo de la mezcla tabaco-betel-hidróxido cálcico entre estudiantes españoles / Consumption of the tobacco-betel-calcium hidroxyde mixture, among Spanish students

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Development and evaluation of calcium hydroxide-coated, pericardium-based biomembranes for direct pulp capping.

AIM: The aim of the present study was to develop a bovine pericardium biomembrane (BPB) and to evaluate pulp response in vivo. METHODS: A double-layer bovine BPB/chitosan was manufactured, and the porous chitosan side was coated with calcium hydroxide. The microstructure of the matrices was evaluated with electron microscopy. To test pulp response, cavities were prepared on the occlusal surface of Wistar rats' mandibular left first molars and capped with matrices, followed by appropriate adhesives/composite restorations. The animals were divided into three groups: group 1, calcium hydroxide alone; group 2, BPB without calcium hydroxide; and group 3, BPB coated with calcium hydroxide. Specimens were processed and histologically evaluated at 7, 14, and 30 days, postoperatively. RESULTS: Electron microscopy showed porous chitosan surface and a cohesive calcium hydroxide layer. Histological analysis showed that groups 1 and 3 had mild odontoblast layer disorganization, but normal pulp tissue appearance at 7, 14, and 30 days. At the same time points, group 2 showed a loss of general pulp tissue, pulp necrosis, and periapical abscess in some teeth. CONCLUSION: Coated bovine pericardium-based biomembranes resulted in favorable outcomes in cases of pulp exposure after a 30-day observation period, and might protect against injuries caused by adhesive systems and composites.

Nonsurgical Clinical Management of Periapical Lesions Using Calcium Hydroxide-Iodoform-Silicon-Oil Paste.

BACKGROUND: The study aim is to avoid tooth extraction by nonsurgical treatment of periapical lesion. It assesses healing progress in response to calcium hydroxide-iodoform-silicon oil paste (CHISP). Numeric Pain Rating Scale was used to validate the approach. Furthermore, CHISP was used to treat cystic lesions secondary to posttraumatic avulsion of permanent teeth. MATERIALS AND METHODS: Over 200 patients with radicular cysts were treated with CHISP through the root canal. Radiographs were used to verify lesion size and position, ensure correct delivery to the site, and monitor the progress of bone healing in the lesion area. Ten males and 10 females were randomly selected for statistical assessment. RESULTS: No severe pain, complications, or failure in cyst healing was reported. Complete healing was achieved in an average of 75 days. Furthermore, healing of radicular cyst secondary to posttraumatic tooth avulsion was successful. CONCLUSION: CHISP indicated an antiseptic effect, which enhanced and shortened healing time of periapical lesions. The less invasive procedure avoids tooth extraction and reduces bone resorption. Cyst management with CHISP can remedy failed root canal treatments. The results show a bone regenerative capacity of CHISP suggested in first rapid phase and a second slow phase.

Root Canal Irrigants and Medicaments in Endodontic Malpractice Cases: A Nationwide Longitudinal Observation.

INTRODUCTION: The aim of this study was to assess the role of root canal irrigants and medicaments in endodontic injuries verified in Finland and to estimate the rate of such events over time. METHODS: The study material comprised all endodontic injuries verified by the Patient Insurance Centre in 2002 to 2006 (n = 521) and 2011 to 2013 (n = 449). The data, based on patient documents scrutinized by 2 specialists in endodontics, included patients' and dentists' sex and age and the service sector. We recorded the use of root canal irrigants and medicaments, each as a dichotomy. Furthermore, we dichotomized the injuries as those related to root canal irrigants/medicaments and any other injuries. The injuries were also dichotomized as avoidable (could have been avoided by following good clinical practice) or unavoidable (normal treatment-related risks). Statistical evaluation used chi-square tests and t tests; logistic regression produced odds ratios (ORs). RESULTS: The verified injuries (N = 970) comprised 635 (65%) avoidable and 335 (35%) unavoidable injuries. The number of irrigant-/medicament-related injuries was 69, accounting for 7.1% of all verified injuries; all resulted from sodium hypochlorite and calcium hydroxide, and 87% were avoidable. The overall rate of sodium hypochlorite/calcium hydroxide injuries was 4.3 cases per 100,000 endodontic patients per year. Compared with other injuries, sodium hypochlorite/calcium hydroxide injuries were more likely avoidable (OR = 3.8) and more than 5-fold likely in 2011 to 2013 than in 2002 to 2006 (OR = 5.6). CONCLUSIONS: Extreme care is needed when applying sodium hypochlorite and calcium hydroxide into root canals to avoid increasing harmful consequences.

Kumkum-induced allergic contact dermatitis: Are we missing the actual culprit?

BACKGROUND: Kumkum, made with turmeric and slaked lime along with colour enhancing dyes is known to cause allergic contact dermatitis. The possible contact allergens in kumkum include turmeric, Sudan-1, 4-aminoazobenzene, brilliant lake red R and cananga oil. We report patch test results among patients with suspected contact hypersensitivity to kumkum. OBJECTIVE: To identify the allergen causing kumkum induced allergic contact dermatitis by patch testing and to advise patients about organic kumkum which doesnot contain colour enhancing dyes. METHODS: Eighteen patients with suspected contact hypersensitivity to kumkum were patch tested with undiluted kumkum, undiluted turmeric, Sudan-1 (95%), 4-aminoazobenzene and allergens of the Indian Standard Series. RESULTS: Of the 18 patients, 14 patients had patch test positivity to kumkum and 4 had a negative reaction to kumkum. Patch test with other suspected contact allergens showed positive reaction to turmeric in 4 patients, Sudan-1 in 3 patients and 4-aminoazobenzene in 2 patients. Among the allergens of the Indian Standard Series, positivity to nickel and fragrance mix was seen in 5 and 2 patients respectively. Positive reaction to PPD, chlorocresol and parthenium was seen in 1 patient each. LIMITATION: Small sample size. CONCLUSION: Allergic contact dermatitis to kumkum occurs both due to the dyes (added for enhancing the colour) and turmeric. All patients with suspected allergic contact dermatitis should be patch tested with kumkum, turmeric and dyes, based on which alternative non-allergic material could be advised. Kumkum dermatitis can also occur due to various other allergens, for which too patch testing should be done.

The Effect of Long-term Dressing with Calcium Hydroxide on the Fracture Susceptibility of Teeth.

INTRODUCTION: Calcium hydroxide has been widely used to treat immature teeth to achieve periodontal healing and to promote the formation of an apical barrier. However, retrospective clinical studies have shown a high incidence of cervical root fractures with long-term calcium hydroxide dressing. The alkalinity of calcium hydroxide has been suggested to weaken the root. In vitro studies using ovine teeth show conflicting results on fracture strength of dentine, although different commercial products may have influenced the results. The purpose of this study was to investigate the effects of 2 commercial products used in prior studies (Calasept Plus and UltraCal XS), as well as a new product (Calmix) that uses a nonaqueous vehicle that allows for a higher pH, on the fracture strength of dentine over time. METHODS: A total of 330 lamb incisor teeth were collected and the canals prepared so that 3 commercial calcium hydroxide products as well as a positive control of pure calcium hydroxide slurry that filled the root canal from the open apex and a negative control of saline was tested. The teeth were loaded until fracture with a universal testing machine at time points 0, 3, 6, and 9 months and the force to fracture was calculated. The data were analyzed with Friedman analysis of variance and Mann-Whitney t tests. RESULTS: No statistical differences were observed between the different calcium hydroxide products and the negative controls. CONCLUSIONS: Thin and fragile roots could be the cause of fracture rather than the calcium hydroxide dressing.

Haemolytic anaemia and hepatocitolysis associated with hypermagnesaemia by repeated exposures to copper-calcium fungicides.

For the medical practice, our manuscript acts as a signal, despite only presenting three cases which feature the association between hepatocytolysis, haemolysis and hypermagnesaemia. This clinical-biologic triad was highlighted with the workers who through the nature of their profession were exposing themselves periodically to vapours which contained copper sulphate neutralised with calcium hydroxide, a fungicide used for fruit trees. We are exclusively assessing the haematological perturbation. In this aetiological context, the generating mechanism for haemolysis is very probable biochemical, where hypercupraemia interferes with cellular antioxidant defence mechanisms. Hypothetically, the role of the redox homeostasis disorder in the intravascular destruction of erythrocytes is sustained, and particularly the coexistence of cell cytolysis in the medullary erythroid compartment, which can be assimilated with a possible ineffective erythropoiesis.

Spectrophotometric analysis of crown discoloration induced by two different sealers: An In vitro study.

CONTEXT: Endodontic materials have been assessed with regards to their potential for dental staining. AIMS: To evaluate the coronal discoloration effect of Apexit Plus and Resino Seal in mandibular premolars using spectrophotometer. SETTINGS AND DESIGN: The study design was original research. MATERIALS AND METHODS: Forty human single-rooted mandibular first premolar teeth were selected for the study. They were divided into four groups of ten specimens each. Group 1 - Apexit Plus sealer, Group 2 - Resino Seal sealer, Group 3 - positive control (Blood), and Group 4 - negative control (distilled water). Teeth were resected 3 mm below at cementoenamel junction. In all samples, access cavities were prepared, instrumented, and irrigated. Sealers were mixed and placed into the pulp chamber through cervical access and control groups were filled with blood and distilled water. Coronal orifices were sealed using self-cure glass ionomer cement. Samples were analyzed using spectrophotometer to determine the discoloration in each group at 10, 17, and 24 days interval. STATISTICAL ANALYSIS USED: Statistical analysis used Wilcoxon signed-rank test. RESULTS: All sealers used in the present study caused a progressive coronal discoloration over a time period of 17-24 days. There was statistically significant difference between resino seal sealer and apexit plus sealer , with resino seal showing greater coronal discoloration. CONCLUSION: Resino seal sealer has greater potential to cause discoloration of crown as compared to apexit plus sealer over a period of time.

Comparison of the Potential Discoloration Effect of Bioaggregate, Biodentine, and White Mineral Trioxide Aggregate on Bovine Teeth: In Vitro Research.

INTRODUCTION: Tricalcium silicate cements can be used for pulp capping, pulpotomies, apical barrier formation in teeth with open apices, repair of root perforations, regenerative endodontics, and root canal filling. The aim of this study was to evaluate and compare the discoloration potential of 3 different tricalcium cements using a bovine tooth model. METHODS: Forty bovine anterior teeth have been used for the study. Crowns separated from the roots were randomly divided into 4 groups: the BioAggregate (IBC, Vancouver, Canada) group, the Biodentine (Septodont, Saint Maur des Fosses, France) group, the mineral trioxide aggregate Angelus (Angelus, Londrina, PR, Brazil) group, and the only blood group. Materials have been placed to the standardized cavities on the lingual surfaces of the crowns, and their contact with blood has been provided. The color values of the samples were measured with a digital tooth shade determinator (VITA Easyshade; VITA Zahnfabrik, Bad Sackingen, Germany) before the placement of the materials, after the placement of the materials, in the 24th hour, in the first week, in the first month, in the third month, and in the first year. The mean value of all groups was compared using the Tukey multiple comparison test (α = 0.05). RESULTS: All groups displayed increasing discoloration during a period of the first year. The "only blood group" showed the highest color change values, and it was followed as BioAggregate, mineral trioxide aggregate Angelus, and Biodentine, respectively. Statistically significant differences were found for Biodentine when compared with the only blood and BioAggregate groups (P < .05). CONCLUSIONS: Considering the results of the study, Biodentine is found to have the least discoloration potential among the tested materials.

A histologic assessment of a HYBENX® oral tissue decontaminant in vital pulp therapy in dogs.

The aim of this study was to assess HYBENX® Oral Tissue Decontaminant (HOTD) in treating vital pulp exposure in a canine model. The use of HOTD solution was compared to an accepted and standard regimen for vital pulp exposure, an application of a commercial calcium hydroxide product (Ca(OH)2). Both control and experimental treatments were followed by restoration with a commercial zinc oxide and eugenol obtundant intermediate restorative material and thermal insulator (ZOE). At 7 days there was 100% pulp vitality with HOTD and 50% with Ca(OH)2. New dentin formation was seen in 62.5% of the HOTD treated pulps and none of the Ca(OH)2 treatment group. The vital pulp exposures at day 21 post treatment with HOTD also showed significant improvement over Ca(OH)2 in the presence of odontoblasts, new dentin formation and pulp survivability. The presence of odontoblasts and new dentin was noted in 71% of the HOTD cases versus 50% of the survivable Ca(OH)2 cases. Furthermore, 100% of HOTD cases had vital pulps versus 62.5% of Ca(OH)2 cases. The 60-day specimens of both experimental and control techniques exhibited histologically similar appearances and were similar in outcomes. HOTD treatment at day 7 showed a significant positive difference, both in the formation of new dentin and tooth vitality. HOTD proved better for the post 21-day specimens and equivalent for the 60-day pulp specimens with no evidence of untoward tissue reactions or results.