Irreversible Hydrocolloid Impression Research Articles

Antimicrobial Efficiency of Hypochlorous Acid Incorporation and its Effect on Surface Properties of Irreversible Hydrocolloid Materials

Objective: Conventional approaches for disinfection, including spraying and immersion, resulted in only surface disinfection of impressions. As a result, self-disinfecting impression materials incorporated with antimicrobial compounds require more extensive studies. The incorporation of a disinfectant into irreversible hydrocolloid impression materials could eliminate the need for the disinfection step by conventional approaches, including spraying and immersion which only result in surface disinfection of impressions. The study was aimed to investigate the effect of incorporation of hypochlorous acid in irreversible hydrocolloid materials on antimicrobial efficiency, detail reproduction, and dimensional stability. Materials and Methods: Hypochlorous acid (HOCl) was used in two concentrations, 100 ppm and 200 ppm, and mixed with alginate powder to compare with the control group (distilled water mixed with alginate). Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosawere chosen for assessing the antimicrobial activity with the disk diffusion test. In addition, the dimensional stability and reproduction of details were tested. Results: The results revealed that both HOCl concentrations of 100 ppm and 200 ppm imposed significant antimicrobial activity against all three tested microorganisms. There was no significant difference regarding reproduction of details, but the addition of the antimicrobial had a significant adverse effect on the alginate’s dimensional stability. Conclusion: It may be concluded that the incorporation of HOCL into irreversible hydrocolloid impression material resulted in an impression with antimicrobial activity. In addition, there was no effect on the impression materials ability to reproduce surface details, but the antimicrobial addition may affect its dimensional stability.

An in-vivo Analysis of the Positional Relationship of Palatal Rugae with Maxillary Teeth in Different Arch Forms Among Young Dentulous Gujarati Individuals-A Pilot Study

Background- The palatal rugae are transverse folds of tissue located in the anterior portion of the hard palate. They are considered to be reliable landmarks with manifold uses in the field of orthodontics and forensics. The current study was carried out with the aim of determining if a positional relationship of palatal rugae exists with the maxillary teeth in individuals with different maxillary arch forms. Material and method- The study was carried out in 100 participitants (87 females and 13 males) . Irreversible hydrocolloid impressions were made and casts were poured in Type 3 dental stone. The casts were divided according to arch forms as taper, ovoid and square. Palatal rugae on the casts were assessed digitally and the position of the most posterior rugae evaluated in relation with the adjacent maxillary teeth. Results –It was observed that the palatal rugae had a higly significant positional relationship with the maxillary posterior teeth(p value <0.0001) . In the ovoid and square arches, majority of the individuals had the most posterior rugae lying at the level of distal margin of 2nd premolar while in cases of taper dental arches, maximum number of individuals had the distal margin of 1st premolar coincide with the most posteriorly located rugae. Conclusion- Hence, it can be concluded that the most posterior limit of the rugae may serve as a reliable guide for the arrangement of the maxillary teeth in different arch forms. Key Words- Palatal Rugae, maxillary anterior teeth , denture aesthetics

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study

Introduction Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual’s dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. Objectives To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Methodology Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. Expected Result It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Conclusion Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren’t many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study.

Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual's dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren't many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

The Physical Properties of Vanillin-Incorporated Irreversible Hydrocolloid Impression Material

Irreversible hydrocolloid impression material is extensively used in dentistry to record and duplicate the details of tooth structure, surrounding tissue, and other intraoral structures. The materials allow dentists to work more easily and perform better diagnosis and treatment planning. When used, the material is exposed to oral microorganisms, some are pathogens, from the patient’s teeth, mucosa, blood, and saliva. These pathogens can be absorbed into the material and transmitted to dentists and other dental workers. Hydrocolloid impression material incorporated with vanillin has been shown to exhibit antimicrobial potential, however, its physical properties have not been performed. Therefore, this study aims to investigate the physical properties of a vanillin-incorporated irreversible hydrocolloid impression material on four different physical properties: working time, setting time, elastic recovery, and strain-in compression. The impression powder was mixed with varying concentrations of vanillin (0.1%, 0.5%, and 1.0% w/w) using the electric vacuum mixer. The impression material without vanillin was used as a control. All the tests were done following the ISO specification 21563: 2021 for dental materials with 15 specimens for each test. The result showed that at concentrations of 0%, 0.1%, and 0.5% w/w vanillin, no significant change in the four physical properties has been observed. However, the working time and setting time values of impression material with 1% vanillin were reduced significantly and did not meet the ISO standard. In conclusion, the incorporation of 0.1%, 0.5%, and 1% w/w vanillin into irreversible hydrocolloid impression material showed a significant reduction in setting time and working time. However, when considering the ISO standard specifications, the 0.1% and 0.5% w/w vanillin-added materials can still be used due to their acceptable values of all physical properties (setting time, working time, elastic recovery, and strain-in compression). These impression materials will be valuable for use in clinical settings to reduce the disinfection procedure and the risk of cross-contamination.

Dimensional Stability of Additively Manufactured Diagnostic Maxillary Casts Fabricated with Different Model Resins.

To evaluate the effect of model resin type and time interval on the dimensional stability of additively manufactured diagnostic casts. Ten irreversible hydrocolloid impressions and 10 impressions from an intraoral scanner were made from a reference maxillary stone cast, which was also digitized with a laboratory scanner. Conventional impressions were poured in type III stone (SC), while digital impressions were used to additively manufacture casts with a nanographene-reinforced model resin (GP) or a model resin (DM). All casts were digitized with the same laboratory scanner 1 day (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) after fabrication. Cast scans were superimposed over the reference cast scan to evaluate dimensional stability. Data were analyzed with Bonferroni-corrected repeated measures ANOVA (α = .05). The interaction between the main factors (material type and time interval) affected anterior teeth deviations, while the individual main factors affected anterior teeth and entire-cast deviations (P ≤ .008). Within anterior teeth, DM had the lowest deviations at T3, and GP mostly had lower values at T2 and lower deviations at T3 than at T0 (P ≤ .041). SC had the highest pooled anterior teeth deviations, and GP had the highest pooled entire cast deviations (P < .001). T3 had lower pooled anterior teeth deviations than at T0, T1, and T4, and higher pooled entire cast deviations than T1 were demonstrated (P ≤ .027). The trueness of nanographene-reinforced casts was either similar to or higher than that of other casts. Dimensional changes were acceptable during the course of 1 month.

Effect of Tooth Mobility on the Accuracy of Conventional Impressions: A Pilot Study.

To study the influence of tooth mobility on the accuracy of conventional impressions. In total, 10 patients with mobile anterior teeth and 10 healthy patients were treated with conventional impressions and intraoral digital impressions. The digital impression group was recorded as standard data, the mobile teeth group was recorded as the experimental group, and the healthy anterior teeth group was recorded as the control group. We imported digital impression and irreversible hydrocolloid impression files into Geomagic Wrap and marked reference points to execute N-point alignment, then we recorded the coordinates. Paired-samples t test was used to analyze whether the point coordinates of mobile teeth were statistically significant (a = .05). One-way ANOVA was used to analyze whether there was a relationship between coordinate differences and tooth mobility in the distal, coronal, and buccal directions (a = .05). In the buccal and coronal directions, the difference was statistically significant between the conventional and digital impression groups. In the buccal direction, the accuracy differences of I-degree and II-degree mobile teeth were 0.149 mm and 0.401 mm, respectively. In the coronal direction, the differences were 0.128 mm and 0.233 mm, respectively. Meanwhile, ANOVA analysis showed that there was a relationship between point coordinate difference and tooth mobility in the buccal and coronal directions. Conventional impressions can influence the accuracy of mobile tooth impressions. Therefore, digital impressions should be adopted for mobile teeth impressions.

Dextrose neuroprolotherapy and occlusal splint treatment outcomes in occlusal trauma: Evaluation through ultrasound imaging.

Occlusal trauma has become a common phenomenon among individuals today. Its primary source is bruxism, which involves unusual activities such as clenching and grinding during the day or sleep. The hypothesis is that with 5% dextrose neuroprolotherapy, both the trigger points and affected nerves will be healed, and the muscle will be relieved by eliminating the pain. This study aimed to compare the short-term ultrasonographic results of patients treated with occlusal splint and 5% dextrose neuroprolotherapy for bruxism. Patients were divided into two groups: the dextrose neuroprolotherapy group and the occlusal splint group. In the first group, patients were administered 5% dextrose three times at one-week intervals using the dextrose neuroprolotherapy method. Impressions for both jaws were made using a high-viscosity irreversible hydrocolloid impression material in the second group. An occlusal splint was tailored to fit the upper jaw. Patients were assessed for masseter muscle thickness and strain ratio using ultrasonography before and 3 months after the treatment. No statistically significant differences were found between the two groups for all measures. Statistically significant differences were observed in the strain ratio of the left musculus massetericus in the resting position and the thickness of the left musculus massetericus in the contracted position exclusively in the neuroprolotherapy group (p=0.001, p=0.011, respectively). Differences in the strain ratio of both sides of the contracted musculus massetericus were demonstrated in both groups (neuroprolotherapy group: right side p<0.001, left side p=0.007, splint group: right side p=0.005, left side p=0.012). This study demonstrates that 5% dextrose neuroprolotherapy is an effective treatment comparable to an occlusal splint. Objectively visualizing changes in the masseter muscle through ultrasound provides clear results in the context of occlusal trauma and bruxism.

OPPORTUNITIES FOR TREATMENT WITH A TEMPORARY OBTURATOR MADE OF THERMOPLASTIC FOIL

Prosthetic treatment with a temporary obturator is an intermediate stage in the overall prosthetic rehabilitation of patients with maxillary resection. According to prevailing opinions, treatment with a temporary obturator should start around 2 weeks to 2-3 months after resection and to continue until the final completion of the healing processes in the defect. Due to the dynamic changes in the defect, this treatment stage is associated with many difficulties, requiring frequent correction of the obturator and up to 12-14 clinical visits on average. The aim of the research is to track the opportunity for fabrication of a temporary obturator of thermoplastic foil with vacuum forming apparatus and its efficiency for restoring speech and fluid intake in patients with maxillary resection. For the aim of the study we conducted a treatment of a 45-year-old patient operated a week ago for maxillary carcinoma. As a result, the left alveolar bone and a part of the hard palate with a diameter of 10 mm were resected, with teeth 13 to 23, 16 and 17 preserved. The defect was padded with gauze and an impression with an irreversible hydrocolloid impression material was taken. In the laboratory a grade 4 plaster working model was cast on which the borders of the palatal plate were outlined. For the frontal teeth, these were the cervical areas of the teeth, and for the distal - their equators. In the area of the defect and the missing teeth the border reached the transitional fold, and distally - the soft palate. The plate was made from foil of 1 mm diameter which was drawn onto the model with a vacuum forming apparatus and was cut along the indicated borders. The palatal plate - obturator successfully closed the comunication to the nasal cavity and restored the opportunity for fluid intake, which was the main problem for the patient. The use of a foil with a thickness of 1 mm provided stability and resistance of the construction. As a result of this, the necessary hermetic seal of the defect was achieved and the speech of the patient was normalised. The described treatment methodology with a temporary obturator allows the successful restoration of speech and fluid intake during the healing processes in the defect. The main advantages of the method are the fast and easy fabrication, the opportunity for multiple corrections and the short period of adaptation.

TO CORRELATE THE RELATIONSHIP OF THE DISTANCE BETWEEN LINGUAL FRENAL ATTACHMENT AND MANDIBULAR INCISAL EDGE POSITION AS AN AID IN ESTABLISHING MANDIBULAR OCCLUSAL PLANE: A CROSS-SECTIONAL SURVEY

Background: The determination of vertical dimension, aesthetics, phonetics and incisal guidance, depends on the placement of anterior teeth. Fewer studies are present for mandibular anterior teeth setting. Therefore this study aims at determining the correlation of distance between lingual frenal attachment and mandibular incisal edge position in dentulous subjects as an aid in establishing mandibular occlusal plane in edentulous patients. Methodology: 318 subjects (161 males and 157 females) under the age group of 18 to 30 years, who met the requisite criteria were seleceted. A mandibular cast was obtained from irreversible hydrocolloid impression in stock trays for each subject. The distance between the incisal edge of lower central incisor and anterior attachment of the lingual frenum was measured using digital vernier caliper. Result:It was observed that the distance between anterosuperior attachment of lingual frenumand mesioincisal edge of mandibular central incisor (CI) in female subjects was 12.19, with mean standard deviation (±SD) of 1.34. and 15.91 with mean standard deviation (±SD) 1.32 in male subjects respectively. Conclusion:Thus, the anterior attachment of lingual frenum is a reliable anatomic landmark and shall aid in setting the mandibular central incisors in a more natural position.

Comparison of Tearing strength and Dimensional Stability of Alginate Impression Material Mixed with Water and Chlorhexidine

Background:&#x0D; An irreversible hydrocolloid impression material combined with two different doses of chlorhexidine solution is tested for dimensional change and tearing strength. The aim of this study is to evaluate the impact of adding chlorhexidine with 2 different available concentrations on alginate impression material.&#x0D; Materials and Methods:&#x0D; According to the manufacturer's instructions, the irreversible hydrocolloid specimens is made and divided into 3groups (Group 1 is mixed with tap water as a control group, Group 2 is mixed with 0.12 chlorhexidine, and Group 3 is mixed with 0.2 chlorhexidine). Testing is done on the change in dimensions and the tearing strength.&#x0D; Results:&#x0D; Lesser dimensional change is observed at group two and is non-significant, and the group three is significantly more dimensionally stable when compared with group one, tearing strength of group one and two is nearly the same while the group three is more resistant to tear and the difference is significant&#x0D; Conclusion:&#x0D; The dimensional stability and tearing resistance of chlorhexidine self-disinfecting irreversible hydrocolloid impression material may vary greatly.

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study

Introduction- Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual's dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. Objectives- To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Methodology- Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. Expected Result- It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Conclusion- Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren't many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

The Antimicrobial Potential of Vanillin-Incorporated Irreversible Hydrocolloid Impression Material

The hydrocolloid impression material is one of the most important materials extensively used in several procedures in the dental field. It is mainly applied for diagnostic and planning in the rehabilitation of oral, orthodontic, and maxillofacial prostheses due to its biocompatibility with the oral tissues, low toxicity, ease of use, and relatively low cost. When doing the impression, the material might be contaminated with blood, saliva, and biofilm from within the patient’s mouth. In these procedures, there are high chance that the microorganisms can be transmitted from patients to the casting materials and then to the dentists or to the dental lab technicians. Several types of disinfectants have been introduced for use to disinfect dental impressions. This study aims to investigate the antimicrobial potential of vanillin-incorporated irreversible hydrocolloid impression material on Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans. The hydrocolloid impression material used in this study is Alginate, Kromopan class A type I, Lascod, Italy. Different concentrations of vanillin (0.1%, 0.5%, and 1% w/w) were added to the impression powder, and the impression samples were made by mixing the alginate powder with water and pouring them on sterile plastic plates. Staphylococcus aureus ATCC 5638, Klebsiella pneumoniae (clinical isolate), Escherichia coli ATCC 11775, and Candida albicans ATCC 10231 were prepared to 105 CFU/ml suspensions in sterile normal saline solution. A total of 100 μL of each microbial suspension was evenly spread onto the surface of the impression and left for 1 min. Then, a 2 x 2 cm2 sterile Whatman filter paper was placed on the impression sample surface to make an imprint and transferred to the Brain Heart Infusion (BHI) agar plate. The number of colonies growing on the BHI agar was counted after incubation at 37°C for 24-48 h. Impression material without vanillin was used as a control. It was found that adding vanillin to the materials could significantly inhibit all tested microorganisms, and the inhibitory efficiency ranged from 12% to 98%. K. pneumoniae showed the most resistance since the inhibitory effect started at 0.5% w/w vanillin and the maximum suppression was 84% at 1% w/w vanillin. On the other hand, S. aureus appeared to be the most sensitive species, as the suppressive response started at 0.1% w/w vanillin and the percentage of inhibition was as high as 98% at 1% w/w vanillin. In conclusion, we combined different concentrations of vanillin (0.1%, 0.5%, and 1% w/w) into the impression material and it showed a significant antimicrobial potential against all tested oral bacteria and yeasts (S. aureus, K. pneumoniae, E. coli, and C. albicans). The suppressive effects were dose-dependent and ranged from 12% to 98%. This did not only disinfect the impression material from the inside but also disinfected the impression from the time it was inserted into the patient’s mouth. Using this hydrocolloid impression material incorporated with vanillin could be beneficial to eliminate cross-infection for dental personnel. Nonetheless, further studies are necessary to investigate some physical properties of this impression material, such as setting time, tensile strength, elastic recovery, and detailed reproduction.

Silicone auricular prosthetics with adhesive retention: a case report

A-18-years-old male came to the Dental and Oral Hospital of Hasanuddin University with a complaint of losing his left ear due to a traffic accident several years ago and often feeling pain in his ear especially when blown by strong winds. The patient wants to make an auricular prosthesis so that his self-esteem returns to normal. The extraoral exa-mination showed convex profile, oval-shaped face, symmetrical eyes, nose and lips, submandibular lymph nodes ex-hibit without complaints. The right and left ears are not symmetrical. Manufacture of silicone auricular prosthesis with adhesive retention. Anatomical impressions of the patient's and his siblings' ears were performed as a guide for duplication of the patient's left ear using an irreversible hydrocolloid impression material. The wax pattern of the ear prosthesis that had been made on the die was paired with the patient to check the size accuracy and left and right symmetry. Then proceed with the process of acrylic packing and coloring. After the laboratory process was com-pleted, insertion is carried out. Signs of successful treatment: silicone ear prosthesis with adhesive retention has restored the patient appearance and self-esteem.

A comparative evaluation of antimicrobial property of traditional and three alternative disinfectants on irreversible hydrocolloid impressions: An in vitro study.

The aim was to compare the efficacy of various herbal disinfectants on irreversible hydrocolloid impressions and to investigate the effectiveness of three herbal disinfectants and a chemical disinfectant against particular pathogens. In vitro -a comparative study. The following methodology was followed to achieve the objectives. Four maxillary impressions were made for each selected patient with irreversible hydrocolloid impression material. The predisinfection swabs were taken from impression sites of teeth 17, 13, 27, and 23 (FDI system of tooth numbering). The impressions were immersed in all four different disinfectants such as 2% glutaraldehyde, Aloe vera solution, 50% neem oil, and apple vinegar solution, then the postdisinfection swabs were taken from the same sites 17,13,27,23 and then cultured onto sheep blood agar and examined for growth, and colony forming units (CFUs) of Streptococcus viridans, Streptococcus mutans, Streptococcus sanguis, and Actinomyces viscosus. The comparative analysis was done for the predisinfection and postdisinfection values in each study group. Descriptive analysis, Kruskal Wallis test, Mann Whitney post hoc test, Wilcoxon signed rank test. The results revealed that the mean CFUs of S. viridans, S. mutans, S. sanguis, and A. viscosus during postdisinfection samples were statistically significant when compared to predisinfection samples. Multiple comparison of the mean CFUs of all 4 microorganisms in the control group and in 50% Neem oil group was significantly lesser compared to A. vera and Apple Vinegar group. CFUs of S. viridans, S. mutans, S. sanguis, and A. viscosus significantly decreased in the 50% neem oil group as well as the control group. As a result, 50% Neem oil was a viable option for disinfecting alginate impressions.

Evaluation of the Efficacy of Novel Self Disinfectant Solution in Irreversible Hydrocolloid Impression Material - An Experimental Study.

Irreversible hydrocolloid materials are widely used for both diagnostic and definitive impression procedures. Impressions can be disinfected by immersion or spraying in any compatible disinfectant. Disinfectants should not adversely affect the dimensional stability of the impression and physical properties of impression material and subsequent dental cast. The study aims to evaluate the efficacy of a hypochlorous disinfectant solution mixed with irreversible hydrocolloid on setting time, antibacterial efficacy, and dimensional stability. Three groups were made with one control group and three alginate impression was made for each participants in the maxillary arch with 24-hours intervals between one another using the same brand of commercially available chromatic alginate. The working and setting time were noted. Bacterial swabs were collected using a dry sterile cotton swab in the mid palatal region. Dental casts were made using type III gypsum. The working and setting time had significant differences whereas the dimension among the cast has no significant difference. Microbial growth analysis had distinct differences among the groups. The self disinfection method using a pioneer solution of hypochlorous HOCl (100 ppm) to mix the alginate impression material rather than the water with the same powder-liquid ratio prescribed by the manufacturer had the same dimensional stability with improved antimicrobial action.

Digital Analysis of the Dimensional Change Of an Irreversible Hydrocolloid Impression Material (Alginate) with Varying Storage Times.

The aim of this study was to digitally measure the dimensional changes in an irreversible hydrocolloid impression material (alginate) resulting from varying storage times under optimal storage conditions. A single type V dental stone control cast was used to make 25 alginate impressions using perforated stock trays. The impressions were randomly assigned into five groups of five samples each (n=5 per group) with varying storage times: Group 1, poured at 15 minutes; Group 2, poured at one hour; Group 3, poured at 24 hours (one day); Group 4, poured at 72 hours (three days); Group 5, poured at 168 hours (seven days). All impressions were stored in sealed Ziploc® plastic bags with a wet paper towel (100% relative humidity) at room temperature and stored according to the assigned group storage times. All impressions were poured in type V dental stone according to the manufacturer's instructions. The casts were scanned with a digital 3D desktop scanner and saved as electronic stereolithography (.stl) files. Each .stl file of the scanned casts were superimposed on the .stl file of the control cast using Geomagic® Control X™ software. Three preselected fixed comparison measuring points (CMP) on each cast were compared to the control cast. Point one (CMP1) was on the midfacial surface of central incisor. Point two (CMP2) and point three (CMP3) were on the mesiobuccal proximal marginal ridge areas of third molars. The discrepancies between the files at each point were analysed with colour maps, and quantified (Table 1). The tolerance was set at ±10μm. CMP scores were analysed using one-way analysis of variance (ANOVA) and Kruskal-Wallis (K-W) non-parametric H tests. Average gap distances across groups ranged from 0.04mm (seven-day group) to 0.06mm (one hour and 24-hour groups). Colour maps indicated increased dimensional change with increased storage time up to one day. After three days, shrinkage up to 139μm was measured. ANOVA results for CMP1 (F[4,20] = 1.65, p = 0.020) and CMP3 (F[4,20] = 0.44, p = -0.78) were not statistically significant. Similarly, K-W results for CMP2 were not significant (χ2= 3.62, p = 0.46). Under optimal storage conditions, there were no significant dimensional changes in casts poured from alginate up to seven days.

Antifungal Activity of Magnesium Oxide and Zirconium Oxide Nanoparticles Incorporated into Alginate Impression Material. In Vitro Study

Aims: The aim of this study was to evaluate the antifungal effect of adding nanoparticles with different concentrations into irreversible hydrocolloid impression materials. Materials and Methods: This study evaluated the antifungal effect of MgO and ZrO2 nanoparticles by Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) and using the Agar-Well diffusion method after incorporation of different concentrations of nanoparticles into irreversible hydrocolloid impression material. Results: The results of this study showed that MIC and MFC of magnesium oxide nanoparticles were 0.2wt% and 0.3wt% respectively and for zirconium oxide nanoparticles were 5wt% and 10wt% respectively. Conclusions: The incorporation of MgO and ZrO2 into irreversible hydrocolloid impression materials acts as antifungal agents.

Utilization of brown algae (Sargassum Sp) as dental impression material

ABSTRACT&#x0D; Two-thirds of Indonesia's territory is mostly waters. The United Nations Convention on the Law of the Sea in 1982 stated that the area of ​​Indonesian waters is 5.8 million km2 and there are 27.2% of all flora and fauna species. Algae is one of the most abundant biological resources in Indonesian waters, which is about 8.6%. In Indonesian waters, there are about 28 species of brown algae from six genera including Dyctyota, Padine, Hormophysa, Sargassum, Turbinaria andHydroclathrus. Brown al-gae have a large alginate content in their cell walls, approximately 40% of their dry weight. The alginate contained in brown al-gae canbe used in industrial fields, such as the dental impression material industry. The main active ingredients in the manufac-ture of irreversible hydrocolloid impression materials are sodium alginate, potassium alginate, and triethanolamine alginate. Sodium alginate and potassium alginate can be extracted from brown algae species such as Sargassum sp.

A technique to facilitate impressions in patients with fixed orthodontic appliances

Accurate irreversible hydrocolloid impressions are difficult to obtain in patients undergoing fixed orthodontic treatment. Although various studies have validated the use of irreversible hydrocolloid material for routine impression-making, the undercuts created by the fixed appliances trap the impression material, resulting in deformation1 or dislodgement of the impression from the tray and sometimes even debonding of the brackets.2 Materials including beading wax, masking tape,3 and silicone putty4 have been proposed for covering the brackets and archwires to increase the accuracy of impressions.