Comparative evaluation of maintenance of cell viability of an experimental transport media "coconut water" with Hank's balanced salt solution and milk, for transportation of an avulsed tooth: An in vitro cell culture study

Evaluation of Viability of Periodontal Ligament Cells using Propolis, Coconut Water, Aleo Vera, and Soy Milk: An In vitro Comparative Study

Objectives

This research was done to assess the periodontal ligament cells viability using propolis, coconut water, aloe vera, and soy milk storage media.

Materials and Methods

Periodontal ligament cells were taken from freshly extracted teeth and stored into four groups of storage media: Group A-propolis, Group B-coconut water, Group C-aloe vera, and Group D-soy milk. Later, the cell viability was assessed at 1, 12, and 24 hours.

Results

The periodontal ligament cell viability was significantly greater in propolis, followed by coconut water, aloe vera, and soy milk.

Conclusion

We found that propolis, coconut water, aloe vera, and soy milk can be used as an effective storage media. These are naturally occurring and easily available storage medium.

In vitro comparative evaluation of different storage media (hank's balanced salt solution, propolis, Aloe vera, and pomegranate juice) for preservation of avulsed tooth

Objectives:

Prognosis of the avulsed teeth is mostly affected by extraoral dry period and storage medium used to store teeth before reimplantation. However, ability of storage media can affect cell viability and success of treatment. Various storage media were tried with some success. The present study was undertaken to comparatively evaluate the efficacy of hank's balanced salt solution (HBSS), propolis, Aloe vera, and pomegranate juice (PJ) in preserving the vitality of periodontal ligament (PDL) cells of avulsed teeth.

Materials and Methods:

Fifty orthodontically extracted sound teeth with healthy PDL were selected for the present study. Selected teeth were randomly divided into study groups (10 in each) and 5 each as positive and negative control groups. All the teeth were immersed immediately after extraction into respective storage media. Data were statistically analyzed using IBM SPSS software for Windows, Version 19.0., IBM Corp., Armonk, NY, USA. Analysis of variance and multiple range were done using Tukey's honestly significant difference with level of significance at 5% (P > 0.05).

Results:

Propolis (285,000 viable cells with standard deviation 4.11028 and standard error of 1.38097) showed more viable PDL cells followed by HBSS, A. vera, and PJ.

Conclusion:

Propolis, A. vera, and PJ can be used as an alternative tooth storage media.

Dentinal Hypersensitivity Treatment Using Diode Laser 980 nm: In Vivo Study

The discomfort of patients due to dentinal hypersensitivity (DH) is one of the main challenges that dentists face in daily practice. Difficulties in DH treatment gave rise to many protocols which are currently used. The aim of this clinical study is to evaluate the effectiveness of a new protocol on the reduction of dentinal hypersensitivity with diode laser 980 nm and the application of a graphite paste. 184 patients enrolled in the study, the degree of pain was evaluated by visual analog scale (VAS), graphite paste was applied on the exposed dentine before irradiation, the application of diode laser 980 nm with continuous mode, backward motion, tangential incidence of the beam in non-contact mode and a delivery output of 1 W. Fiber’s diameter was 320 μm and total exposure time depended on the time necessary to remove the graphite paste from the teeth. Statistical analyses were performed with Prism 5^® software. Pain in post-operative significantly decreased immediately after the treatment. Mean values stayed stable until a 6-month follow-up. The application is considered to be safe with long-term effectiveness.

In Vivo Safety and Regeneration of Long-Term Transported Amniotic Fluid Stem Cells for Renal Regeneration

Background

Despite major progress in stem cell therapy, our knowledge of the characteristics and tissue regeneration potency of long-term transported cells is insufficient. In a previous in vitro study, we established the optimal cell transport conditions for amniotic fluid stem cells (AFSCs). In the present study, the target tissue regeneration of long-term transported cells was validated in vivo.

Methods

For renal regeneration, transported AFSCs were seeded on a poly(lactide-co-glycolide) scaffold and implanted in a partially resected kidney. The target tissue regeneration of the transported cells was compared with that of freshly harvested cells in terms of morphological reconstruction, histological microstructure reformation, immune cell infiltration, presence of induced cells, migration into remote organs, expression of inflammation/fibrosis/renal differentiation-related factors, and functional recovery.

Results

The kidney implanted with transported cells showed recovery of total kidney volume, regeneration of glomerular/renal tubules, low CD4/CD8 infiltration, and no occurrence of cancer during 40 weeks of observation. The AFSCs gradually disappeared and did not migrate into the liver, lung, or spleen. We observed low expression levels of pro-inflammatory cytokines and fibrotic factors; enhanced expression of the genes Wnt4, Pax2, Wt1, and Emx2; and significantly reduced blood urea nitrogen and creatinine values. There were no statistical differences between the performance of freshly harvested cells and that of the transported cells.

Conclusion

This study demonstrates that long-term transported cells under optimized conditions can be used for cell therapy without adverse effects on stem cell characteristics, in vivo safety, and tissue regeneration potency.

Awareness about Management of Tooth Avulsion among Dentists in Jazan, Saudi Arabia

AIM

This study aimed to evaluate the awareness amongst dentists working in Jazan, a city in K.S.A., about their potential role in the treatment of traumatic tooth avulsion injuries.

MATERIAL AND METHODS

A cross-sectional study was performed and all dentists in Jazan, K.S.A. were invited to participate in this study. Data was collected through a self-administrated questionnaire. A total of 200 dental practitioners answered the questionnaire. The intern/general practitioners were 75%, and the specialists were 25%. The variables comprised socio-demographic information, professional characteristics and information regarding the awareness towards the management of tooth avulsion.

RESULTS

A total of 200 dental practitioners answered the questionnaire. The intern/general practitioners were 75%, and the specialists were 25%. (44.3%) were aware of the critical time for avulsed tooth replantation while 71.8% of females did not know about the critical time for avulsed tooth replantation. 50.0% of the specialists reported that less than 30 min was needed for avulsed tooth replantation, while 59.3% of interns/general dentists advised less than 60 minutes.

CONCLUSION

A statistically significant result was observed regarding the best storage medium, a critical time for avulsed tooth replantation and tooth management before replantation.

Human periodontal fibroblasts viability stored in Custodiol® , coconut water, and propolis. An ex vivo study

BACKGROUND/AIMS

Successful replantation of an avulsed tooth depends on the regeneration of periodontal ligament (PDL) attachment which is affected by the transport medium, dry time, and storage time. Various storage media have been studied but the search for the optimum storage medium is still needed to determine the ideal material and storage time to maintain PDL cells. The aim of this study was to determine the ability of Custodiol® , coconut water (CW) from different stages of maturity, and propolis as storage media for avulsed teeth by evaluating the viability of PDL cells for different time intervals.

MATERIALS AND METHODS

PDL cultures were subjected to Cutodiol® , immature, half mature, and mature coconut water, and different concentrations of propolis in Dulbecco's Modified Eagles Medium (DMEM). Culture plates with the tested media were incubated for 1, 2, 6, 24, 48, 72, and 168 hour. PDL fibroblast cell viability was assessed by MTT assay.

RESULTS

CW showed significantly higher viability of cells than other groups at 6 hour with half mature CW being superior. Propolis at 6.25 mg/mL in DMEM resulted in 138% viable PDL and it was able to preserve PDL cells for up to 168 hour.

CONCLUSIONS

Half mature and mature CW are superior storage media if replantation of avulsed teeth is within 6 hour. Propolis in DMEM could be a potential storage media for prolonged storage intervals up to 48 hour.

Efficiency of Castor Oil as a Storage Medium for Avulsed Teeth in Maintaining the Viability of Periodontal Ligament Cells

STATEMENT OF THE PROBLEM

Researchers always seek a new storage medium for avulsed teeth. Castor oil is a vegetable oil with several advantages such as antimicrobial and antioxidant properties, low toxicity, and glutathione preservation capability, low cost, and high availability.

PURPOSE

The purpose of this study was to evaluate and compare the capacity of castor oil as a new storage medium in preserving the viability of periodontal ligament (PDL) cells compared to Hank's balanced salt solution (HBSS) and milk.

MATERIALS AND METHOD

Forty freshly extracted human teeth were divided into 3 experimental and 2 control groups. The experimental teeth were stored dry for 30 min and then immersed for 45 min in one of the following media; castor oil, HBSS, and milk. The positive and negative control groups were exposed to 0 min and 2 h of dry time respectively with no immersion in any storage medium. The teeth were then treated with dispase grade II and collagenase and the number of viable PDL cells were counted. Data were analyzed using Kruskal- Wallis test.

RESULTS

The percentage of viable cells treated with castor oil, HBSS and milk counted immediately after removal from these media were 46.93, 51.02 and 55.10 % respectively. The statistical analysis revealed that the value for castor oil was significantly lower than HBSS and milk (p> 0.05).

CONCLUSION

Within the parameters of this study, it appears that castor oil cannot be served as an ideal medium for storage of avulsed tooth. More investigations under in vivo conditions are required to justify the results of this study.

Simplified conditions for storing and cryopreservation of dental pulp stem cells

OBJECTIVES

This study aimed to simplify the collection, isolation and cryopreservation procedure of human dental pulp stem cells (DPSCs) to ease the establishment of dental stem cell banking.

DESIGN

Extracted third molars were collected and stored either in growth medium or in gentamicin-saline (480μg/ml) for 6, 9 or 12h. DPSCs were isolated and subjected to cryopreservation by a controlled-rate or rapid freezing method in 5 or 10% DMSO. Flow cytometry and growth pattern of DPSCs before and after cryopreservation were conducted.

RESULTS

Rate of contamination by which the extracted teeth were stored in control and gentamicin-saline were 9.1% (N=33) and 2.3% (N=43), respectively. Successful cell isolation rate of teeth preserved in gentamicin-saline at 6h (92.9%) was comparable to those of growth media group (90.3%). At 9 and 12h, the rates dropped significantly to 75% and 54%, respectively. Cryopreservation by controlled-rate freezing either in 5 or 10% DMSO resulted in a significantly higher percentage of viable cells than by rapid freezing. Cells conserved by controlled-rate freezing in 5% DMSO showed a pattern of growth similar to control unfrozen cells; 10% DMSO significantly deteriorated the growth pattern of the cells. After thawing, DPSCs conserved by controlled-rate freezing still expressed stemness characteristics, although hematopoietic stem cell markers were slightly increased.

CONCLUSION

Gentamicin-saline was effective in preserving human teeth for DPSC isolation. Controlled-rate freezing in 5% DMSO gave the highest rate of cell viability. This study simplifies the storage conditions and proposes a simple method for cryopreservation of DPSCs.

Nature's Benefaction as a Life Saver for an Avulsed Tooth: An In vitro Study

INTRODUCTION

Dentoalveolar trauma is a very common and avulsion is the most frequent injury. Treatment of choice following avulsion is immediate reimplantation. However, in cases where this might not be possible the prognosis of reimplanted teeth can be improved by the selection of an appropriate storage media. Prevention of ankylosis and replacement resorption depends more on the potential of storage media to maintain cell viability rather than the extraalveolar time period.

AIM

To compare and evaluate the efficacy of different storage media in maintaining the viability of Periodontal Ligament (PDL) cells in an avulsed tooth.

MATERIALS AND METHODS

A total of 58 freshly extracted human premolar teeth were divided into four experimental groups and two control groups. The positive and negative controls corresponded to 0 minute and an eight hours dry time, respectively. The experimental teeth were stored dry for 30 minutes and then immersed in one of the four media: Hank's Balanced Salt Solution (HBSS), coconut water, aloe vera and saline for 45 minutes. The teeth were then treated with Collagenase Type II and Dispase for 30 minutes. The number of viable PDL cells were counted with a haemocytometer and analysed. The statistical analysis was done using SPSS version 15.0. The Analysis of Variance (ANOVA) and Post-hoc tests (Tukey-HSD) were performed to reveal the statistical significance. The values were represented in number (%) and mean±SD.

RESULTS

Statistical analysis demonstrated that among the experimental groups maximum percentage of viable cells were seen in HBSS (87.33%) followed by coconut water (79.87%), aloe vera (70.59%) and saline (50.56%).

CONCLUSION

Within the parameters of this study, it can be concluded that the HBSS is the most effective storage media in maintaining the viability of PDL cells. However, in Indian scenario where availability of HBSS is questionable, coconut water can be considered as the best natural storage media for an avulsed tooth followed by aloe vera.

Effects of tooth storage media on periodontal ligament preservation

BACKGROUND/AIMS

An easily available tooth storage medium is required to preserve a tooth after avulsion. Milk and Hank's balanced salt solution (HBSS) are recommended as tooth storage media, and egg white is also reported to be comparable with milk. The aim of this study was to histologically and immunohistochemically evaluate the effect of different tooth storage media on the periodontal ligament (PDL) of extracted teeth.

MATERIALS AND METHODS

This experiment used HBSS, milk, and egg white as tooth storage media. A total of ninety-six 6-week-old male Sprague-Dawley rats were used in these experiments. In each experiment, six rats were used for each medium and for the control group. Extracted rat molar teeth were immersed in these three different storage media for 1 hour. In each medium, six samples (n=18) were fixed immediately, and the remaining samples (n=54) were subcutaneously transplanted. In the control group (n=24), the extracted teeth were fixed or transplanted immediately after extraction. At day 4, 1 and 2 weeks after transplantation, the teeth were examined by radiographic, histological, and immunohistochemical methods. The number of PDL cells in the storage media was also counted.

RESULTS

Teeth immersed for 1 hour in milk showed the thinnest PDL. Immunohistochemistry of periostin and CD68 labeling suggested degradation of the extracellular matrix in the PDL. In the media used for immersion, more PDL cells were observed in milk than in the other solutions. After transplantation, the HBSS and egg white groups maintained adequate thickness of PDL but in the milk group, thinner PDL and ankylosis were observed.

CONCLUSION

Adequate thickness of PDL was maintained in the egg white group, whereas the milk group showed disturbance in the PDL, which may lead to ankylosis.

An In vitro Comparison of Coconut Water, Milk, and Saline in Maintaining Periodontal Ligament Cell Viability

Background and Objectives:

Two of the most critical factors affecting the prognosis of an avulsed tooth after replantation are extraoral dry time and the storage media in which the tooth is placed before treatment is rendered. The present study is undertaken to evaluate the periodontal ligament (PDL) cell viability after storage of teeth in different storage media, namely, coconut water, milk, and saline.

Materials and Methods:

Forty sound human premolars undergoing extraction for orthodontic purpose were selected. The teeth were allowed to lie dry on sand/mud for 30 min followed by which they were randomly divided and stored in three different media, i.e., coconut water, milk, and saline. After 45-min storage in their respective media, the root surface was then scraped for PDL tissue.

Results:

The ANOVA and Newman–Keuls post hoc procedure for statistical analysis of viable cell count under a light microscope using hemocytometer demonstrated that coconut water preserved significantly more PDL cells viable (P < 0.05) compared with milk and saline.

Conclusion:

Storage media help in preserving the viability of PDL cells when immediate replantation is not possible. This study evaluated the posttraumatic PDL cells’ viability following storage in three different storage media. Within the parameters of this study, it was found that coconut water is the most effective media for maintaining the viability of PDL.

Evaluation of coconut water neutralized by different agents on the viability of human fibroblasts: an in vitro study

Abstract Objective This study evaluated four types of pH adjustment of the coconut water (CW) on viability of human fibroblasts (HFF). Material and method Natural and industrialized CW were adjusted to pH 7.0 using: (1) Sodium Hidroxide (NaOH), (2) Sodium bicarbonate (NaHCO3), (3) Triethanolamine (C6H15NO3), (4) 2-Amino-2-Methil-1-Propanol (C4H11NO). Fibroblasts were plated at 2×104/ well in 96 well plates and maintained in the CW solutions for 2 h and 4 h. Positive control was represented by HFF maintained in DMEM and the negative control by tap water. Cell viability was analyzed by MTT formazan method. Data were analyzed by 3-way ANOVA followed by Tukey’s and Dunnet’s test. Result There are no significant effect on the cell viability regarding type of CW, period of evaluation, and the interactions between CW and period of evaluation, CW and pH adjustment method, pH adjustment method and period of evaluation (p>0.05). Conclusion The product used for CW pH adjustment did not influenced HFF viability, thought there are a tendency of better performance in natural CW.

Storage media for avulsed teeth: a literature review

Dental avulsion is the most severe type of traumatic tooth injuries because it causes damage to several structures and results in the complete displacement of the tooth from its socket in the alveolar bone. The ideal situation is to replant an exarticulated tooth immediately after avulsion because the extraoral time is a determinant factor for treatment success and for a good prognosis. However, it is not always possible. The success of replantation depends on a number of factors that may contribute to accelerate or minimize the occurrence of root resorption or ankylosis, among which is the type and characteristics of the medium used for temporary storage during the time elapsed between avulsion and replantation. Maintaining the tooth in an adequate wet medium that can preserve, as longer as possible, the vitality of the periodontal ligament cells that remain on root surface is the key to success of replantation. Recent research has led to the development of storage media that produce conditions that closely resemble the original socket environment, with adequate osmolality (cell pressure), pH, nutritional metabolites and glucose, and thus create the best possible conditions for storage. Although these storage media can now be purchased in the form of retail products, the most common scenario is that such a product will not be readily available at the moment of the accident This paper reviews the literature on the different storage media that have been investigated for avulsed teeth based on full-length papers retrieved from PubMed/Medline, Lilacs, BBO and SciELO electronic databases using the key words 'storage medium', 'transportation medium', 'avulsion', 'tooth avulsion', 'replantation', 'tooth replantation', 'milk' and 'propolis'. After application of inclusion and exclusion criteria, 39 papers were selected and critically reviewed with respect to the characteristics, efficacy and ease of access of the storage medium. The review of the literature showed that a wide array of types of wet storage media have been evaluated in laboratory studies and clinical reports, including cell and tissue culture solutions like Hank's Balanced Salt Solution (HBSS); medical/hospital products developed specifically for organ storage purposes, such as Viaspan® and Euro-Collins®; culture media, like Minimum Essential Medium (MEM); saline; natural products like water, saliva, bovine milk and its variations, propolis, green tea, Morus rubra (red mulberry), egg white and coconut water; rehydrating solutions, like Gatorade® and Ricetral, and even contact lens solutions. Based on the literature, it could be stated that, so far, apart from Based on the literature, it could be stated that, so far, apart from solutions designed specifically for storage and culture purposes, regular pasteurized whole milk is the most frequently recommended and with the best prognosis among other solutions that are likely to be available at the scene of an accident, such as water, saline or saliva. Its advantages include its high availability, ready accessibility, physiologically compatible pH and osmolality (fluid pressure) with the root-surface adhered PDL cells, presence of nutrients and growth factors. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on.

Effect of fibroblast growth factor on injured periodontal ligament and cementum after tooth replantation in dogs

PURPOSE

The purpose of this animal study was to perform a histological and histomorphometric analysis in order to elucidate the effect of fibroblast growth factor-2 (FGF-2) on injured periodontal ligament (PDL) and cementum after tooth replantation in dogs.

METHODS

The roots of 36 mandibular premolars from six mongrel dogs were used in this study. The roots were randomly divided into three groups: (1) a positive control group (n=12), in which the PDL was retained; (2) a negative control group (n=12), in which the PDL and the cementum between the notches were removed; and (3) an experimental group (n=12), in which the PDL and the cementum between the notches were removed and the roots were soaked in an FGF-2 solution (30 µg/0.1 mL). After treating the root surfaces, the extracted roots were replanted into extraction sockets. The animals were sacrificed four and eight weeks after surgery for histologic and histomorphometric evaluation.

RESULTS

At four and eight weeks, normal PDLs covered the roots in the positive control group. In the negative control group, most replanted roots showed signs of replacement resorption. In the experimental group, new PDL-like tissue and cementum-like tissue were observed to partially occupy the region between the root surfaces and the newly formed bone. Histomorphometric analysis showed that the mean length of the newly formed cementum-like tissue on the roots treated with FGF-2 was significantly greater than that of the tissue on the roots in the negative control group (four weeks, P=0.008; eight weeks, P=0.042). However, no significant differences were observed between the roots treated with FGF-2 and the negative control roots with respect to newly formed PDL-like tissue.

CONCLUSIONS

The results of this study suggest that use of FGF-2 on injured root surfaces promotes cementogenesis after tooth replacement in dogs.

Instant transport media for biopsied soft tissue specimens: a comparative study

Background. Formalin, a traditionally preferred fixative in the field of pathology, has restricted usage in private settings. Since its toxicity violates the Occupational Safety and Health Administration regulations, an eco-friendly alternative would be the need of the hour. Hence an instant media which is economical and nontoxic and enables easy transport of biopsied soft tissue specimens in its original state is of vital importance. Materials and Methods. Commercially available fresh goat buccal mucosa specimens were sliced into smaller bits of equal dimensions and placed in six different containers containing 20% honey, 30% jaggery, milk, and ice for 1 hr, 6 hours, 12 hours, and 24 hours each with formalin as a positive control. After the set time interval, the specimens were fixed in 10% buffered formalin for 24 hours followed by routine processing and staining. The histologic interpretations were a blinded procedure and evaluated by two experts. Results were statistically analysed. Results. 30% jaggery proved to be an ideal transport media showing high quality preservation after 24 hours. 20% honey and ice showed optimal tissue preservation up to 6 hours following which quality deteriorated. Tissues transported in milk showed poor preservation. Conclusion. 30% jaggery can be endorsed in routine histopathological analysis as a transport media.

What is the Best Root Surface Treatment for Avulsed Teeth?

Dental avulsion is the most severe type of traumatic tooth injuries since it causes damage to several structures and results in avulsion of the tooth from its socket. Management protocols for avulsed teeth should include management of the pulp and periodontal ligament (PDL) cells in order to improve the long-term prognosis and survival of these teeth. The prognosis of the treatment as well as the survival of an avulsed tooth depends on intrinsic and extrinsic factors, such as the duration of the tooth's extra-alveolar period, replantation time, the type of storage medium, PDL status and duration of splinting. Recent research has led to the development of storage media. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on. On the other hand in case of delayed replantation, due to the great risk of tooth loss after avulsion, different root surface treatments have been proposed to prevent and delay root resorption before replantation. For this purpose, researchers have applied some different root surface treatment modalities in delayed replantation of avulsed teeth. Several protocols have been used to maintain PDL viability; some involve fluorides, steroids, sodium alendronate, enamel matrix derivatives (EMD) and basic fibroblast growth factor (bFGF, FGF-2). Among these applications, bFGF shows promising results in the regeneration of natural tooth structures and tissues. Better understanding of mechanism of bFGF may help to improve new technologies of regeneration of tooth structures.

Taurolidine specifically inhibits growth of neuroblastoma cell lines in vitro

BACKGROUND

Neuroblastoma is a common pediatric solid tumor with poor outcome for metastatic disease. Thus, novel therapeutic options are of main interest. The anti-neoplastic properties of taurolidine have been demonstrated on a variety of human cancer cells. However, data on neuroblastoma is lacking. Therefore, our aim was to evaluate the effect of taurolidine on growth of neuroblastoma cell lines.

MATERIALS AND METHODS

Neuroblastoma SK-N-BE(2)-M17 and SK-N-SH cells and nonmalignant human umbilical vein endothelial cells as controls were incubated with increasing concentrations of taurolidine (100, 250, 500 µM). Cell growth was examined after 12, 24, and 48 hours of exposure.

RESULTS

Inhibition of cell growth by taurolidine was seen in both malignant cell lines. When compared with human umbilical vein endothelial cells, the neuroblastoma cell lines were significantly more responsive to taurolidine.

CONCLUSIONS

The observed negative impact on cell growth, highly distinctive in SK-N-BE(2)-M17 and SK-N-SH, implies a taurolidine-specific mode of action that appears dependent on differences on cellular and molecular level. Further investigations are warranted to evaluate its mechanism and probable clinical use.

Dentinal tubules sealing by means of diode lasers (810 and 980 nm): a preliminary in vitro study

OBJECTIVE

The aim of this study was to evaluate the effect on dentinal surfaces of diode lasers (810 and 980 nm) at different parameters.

MATERIALS AND METHODS

Twenty-four caries-free human impacted wisdom teeth were used. The crowns were sectioned transversely in order to expose the dentin. The smear layer was removed by a 1 min application of ethylenediaminetetraacetic acid (EDTA). Each surface was divided into four quadrants irradiated at a different output power setting for each kind of laser: 0.8, 1, 1.6, and 2 W (energy densities: 2547, 3184, 5092, and 6366 J/cm(2), irradiation speed 1 mm/sec; optical fiber diameter: 200 μm; continuous and noncontact mode). Half of the samples were stained with a graphite paste. All specimens were sent for scanning electron microscopic (SEM) analysis. Pulp temperature increases in additional 20 teeth were measured by a thermocouple.

RESULTS

Diode laser irradiations at 0.8 and 1 W led to occlusion or narrowing of dentin tubules without provoking fissures or cracks. The application of graphite paste increased the thermal effects in dentin. Measurements of pulp temperature showed that irradiations at 0.8 and 1 W for a period of 10 sec in continuous mode increased pulp temperature (T ≤2°C).

CONCLUSIONS

Diode lasers (810 and 980 nm) used at 0.8 and 1 W for 10 sec in continuous mode were able to seal the dentin tubules. These parameters can be considered harmless for pulp vitality, and may be effective in the treatment of dentinal hypersensitivity.

The effect of propolis as a biological storage media on periodontal ligament cell survival in an avulsed tooth: an in vitro study

OBJECTIVE

Both the length of extra-alveolar time and type of storage media are significant factors that can affect the long-term prognosis of replanted teeth. This study aims to compare propolis 50%, propolis 10%, Hank's balanced salt solution (HBSS), milk and egg white on periodontal ligament (PDL) cell survival for different time points.

MATERIALS AND METHODS

: In this in vitro experimental study, we divided 60 extracted teeth without any periodontal diseases into five experimental and two control groups that consisted each experimental group with 10 and each control group with 5 teeth. The storage times were one and three hours for each media. The controls corresponded to 0-minute (positive) and 12-hour (negative) dry time. Rinsing in the experimental media, the teeth were treated with dispase and collagenase for one hour. Cell viability was determined by using trypan blue exclusion. Statistical analysis of the data was accomplished by using two-way analysis of variance (ANOVA) complemented by the Tukey's HSD post-hoc.

RESULTS

Within one hour, there was no significant difference between the two propolis groups, however these two groups had significantly more viable PDL cells compared to the other experimental media (p<0.05). The results of the three-hour group showed that propolis 10% was significantly better than egg white, whereas both propolis 10% and 50% were significantly better than milk (p<0.05).

CONCLUSION

Based on PDL cell viability, propolis could be recommended as a suitable biological storage media for avulsed teeth.

Effect of Coconut Water Concentration on Survival of Bench-Dried Periodontal Ligament Cells

Background : Coconut water is a biological and sterile liquid. It contains a variety of electrolytes, sugars and amino acids. The purpose of this study is to evaluate the effect of concentration and maturity of coconut water on its ability to preserve human PDL cell viability after exposure to dry time of up to 120 minutes using an in vitro cell culture model.

Methods : PDL cells were obtained from sound permanent first molars which were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM). Cultures were subjected to 0, 30, 60, 90 and 120 minutes dry periods then incubated with 100 and 50% young and mature coconut water for 45 minutes at room temperature (18-26°C). Untreated cells at 0 and 120 minutes, and cells incubated in DMEM served as controls. PDL cell viability was assessed by MTT assay. Statistical analysis of data was accomplished by using one-way analysis of variance complemented by Tukey test, and the level of significance was 5% (p < 0.05).

Results : 100% mature coconut water (MCW) was better than 50% dilutions obtained from mature or young coconuts. However, no significant benefit to the cells was noticed from the addition of the soaking step prior to 30 minutes dry time.

Conclusion : Avulsed teeth which are left dry for > 30 minutes may be benefited from soaking in 100% mature coconut water; further studies on simulated avulsion in animal models are needed to verify the above results.