Conventional Alginate Impressions Research Articles

Intraoral optical impression versus conventional impression for fully edentulous maxilla: an in vivo comparative study.

The aim of the present in vivo study was to compare the clinical trueness of primary mucostatic impressions obtained either by a classical alginate or an optical intraoral scanner technique in patients with a fully edentulous maxilla. A total of 30 patients with a fully edentulous maxilla were included in the study and underwent both conventional impressions and intraoral optical impressions (Trios 3). The conventional impressions were casted and the resulting plaster casts were digitized using a desktop scanner (Imetric D104i). These digitized impressions were superimposed over the optical impressions to compare the differences between the two data sets. Statistical analyses were performed to identify relevant deviations. For the 30 intraoral impressions, 80.88% of the surface areas were below the tolerance threshold of 25 µm and were thus considered similar to the areas scanned with the desktop scanner from the reference plaster cast. Interestingly, the differences (19.12% of the surface areas) were localized in depressible areas such as the vestibule, soft palate, incisive papilla, and flabby ridges. These locations were consistent with the mean of positive differences of +22.8 µm, indicating deformation or less compression with the use of the intraoral scanner. The digital primary impression of the fully edentulous maxilla can be considered similar to the conventional alginate impression except in the depressible areas. Considering the mucostatic objective of such a primary impression, one may consider the optical impression to be more accurate than the conventional one.

Comparative evaluation of the dimensional accuracy of two commercially available extended pour alginates and a conventional alginate impression material at various time intervals – An in vitro study

Because of its acceptable accuracy, affordable price, accessible availability, and simplicity of handling, alginate impression materials continue to be a crucial component of dental practice despite many developments.The purpose of this study was to evaluate and compare the dimensional accuracy of two commercially available extended pour alginates (Cavex ColorChange and Algeniux) and a conventional alginate impression material (Zelgan) at different time intervals. On a maxillary model (Columbia Dentoform, Long Island City, N.Y.) the canines and the first molars were replaced with metal dies. This was selected as the master model. A ‘+’ mark was inscribed on these metal dies to serve as a reference for measurements. A self-cure acrylic resin custom tray was fabricated such that it was positioned over the model in the same spatial relationship with equal amount of space between the tray and model every time an impression was made. A total of 180 impressions were made of the master model, 15 impressions with each material at four different time intervals; immediate, 30 minutes, 48 hours (2 days) and 120 hours (5 days) to obtain gypsum cast. Manufacturer recommended water/powder ratios and storage conditions were followed in the process. Following the designated storage time interval, the casts were poured in minimum expansion Type IV dental stone. Measurements were done with a coordinate measuring machine after 7 days when the casts were completely dry. To evaluate and compare the dimensional accuracy of materials across various time points, for each group, the mean and standard deviation were estimated and subjected to statistical analysis. Two Way Repeated Measure Analysis of Variance (ANOVA) was performed to determine if the dimensions differed significantly across groups with time. The pair wise analysis for materials and time points was performed using Tukey’s post-hoc test. The p value was taken as significant when less than 0.05.Across different time points, a minimum % change was observed at immediate time point, which gradually increased at 30 minutes and at 48 hour, but at 120 hour the % change was maximum for all dimensions. Among three groups, Cavex ColorChange material showed minimum % change across time points, whereas Zelgan group showed maximum % change across all dimensions. All the paired differences were statistically insignificant (p > 0.05) for Algeniux and Cavex ColorChange group. But for Zelgan group, the difference between all the pairs of time points were statistically significant (p < 0.05), except for the pair immediate vs. 30 minutes. These results suggest that Zelgan material showed significant changes after 30 min for all the dimensions.: The results revealed that both the extended pour alginates Cavex ColorChange and Algeniux produced dimensionally accurate casts at all time intervals while the conventional alginate, Zelgan was accurate only at immediate and 30-minute time interval. It was also observed that, among the 4-time intervals investigated, most accurate casts were obtained when the impressions were poured immediately.

A comparison study: The use of digital and conventional impression techniques in dental hygiene education.

The study aimed to assess the applicability of digital intraoral scanning in dental hygiene education and compare the quality, efficiency, and ease of use to conventional impression techniques. Twenty-eight first-year dental hygiene students (DH1) at UTHealth Houston School of Dentistry (UTSD) participated in this 2022 study. Each student participated in two 4-h lab sessions. Students took traditional alginate impressions and digital intraoral scans using Planmeca Romexis on standardized teeth during the first and second sessions. Both techniques were assessed by faculty for quality and efficiency using a standardized rubric. Participants completed a post-survey providing insight into their perceptions of both techniques and ease of use. The study had 100% participation in the lab sessions and survey responses (N=28). The results showed digital scanning produced a statistically higher quality product than conventional alginate impressions (p=0.023). The study found no statistical difference in the efficiency between the two methods. The majority of students (82%) agreed that digital intraoral scanning was easy to use (p=0.001), and 89% agreed they would use digital intraoral scanning in clinical courses to help with patient care (p=0.03). In this study, dental hygiene students with limited clinical experience learned new technology and used it to produce quality impressions compared to the conventional technique, indicating the value of introducing digital dentistry early in dental hygiene education.

Comparative Analysis of the Comfort of Children and Adolescents in Digital and Conventional Full-Arch Impression Methods: A Crossover Randomized Trial.

A monocentric, analytical, controlled crossover study was designed to compare conventional impression and digital impression with two intraoral scanners (iTeroTM and PrimescanTM) in children and teenagers. Patient comfort was evaluated using a 100 mm VAS scale adapted to Spanish and for children. A descriptive and analytical statistical method was conducted with a confidence level of 95% (p ≤ 0.05) and asymptotic or bilateral significance. A total of 51 subjects were enrolled in the study (mean age = 12.35 years). Although the group of 10-14-year-olds was the most numerous, gender was equally distributed among the age groups. None of the variables on the VAS scale showed differences between the gender categories (p > 0.05). There were differences (p < 0.05) with respect to the age categories, as the middle adolescent group showed the worst general perception and total comfort during the conventional impression. Statistically significant differences were found between all VAS scale items and the three impression methods (p < 0.05). The digital impression technique is superior in terms of total comfort to the conventional alginate impression in children and adolescents.

Comparative evaluation of accuracy, time and patient acceptance between intraoral scanner and conventional alginate impression technique – An invivo study

Orthodontists use various dental records such as dental models or casts for diagnosis and treatment planning which includes making of dental impressions and study casts. Conventional alginate impressions are challenging for the patients with extreme gag reflex, irritation &amp; discomfort. Recently 3D technology has led to development of scanning and digital models, but one major concern has been the accuracy. So this study was done to compare the accuracy, time and patient acceptance between intraoral scanner and conventional alginate impression technique. 15 patients were selected. Alginate impressions were made using zhermack neocolloid. The patients were subjected to digital scanning with Medit i500 intraoral scanner. Procedures were timed. After the impressions, each patient was asked to complete survey. Tooth width measurements were made using digital vernier caliper from stone models. In the second method digital images were measured using medit link software. Anterior and overall Bolton ratio was calculated to determine accuracy. Digital impressions are accurate and comparable to conventional impressions as tooth width measurements did not differ significantly. Conventional impression consumed more time. Patients preferred digital impressions.Intraoral scanners are accepted by patients and they have comparable accuracy and time efficient compared to conventional impression.

What to Prefer in Patients with Multibracket Appliances? Digital vs. Conventional Full-Arch Impressions-A Reference Aid-Based In Vivo Study.

This study aimed to investigate the transfer accuracy and required time for digital full-arch impressions obtained from intraoral scanners (IOSs) versus conventional alginate impressions (CAIs) in patients with multibracket appliances (MBA). Thirty patients with buccal MBAs (metal brackets, archwire removed) were examined using an established reference aid method. Impression-taking using four IOSs (Primescan, Trios 4, Medit i700, Emerald S) and one CAI with subsequent plaster casting were conducted. One-hundred-twenty (n = 30 × 4) scans were analyzed with 3D software (GOM Inspect) and 30 (n = 30 × 1) casts were assessed using a coordinate measurement machine. Six distances and six angles were measured and compared to the reference aid values (ANOVA; p < 0.05). Except for the intermolar distance, transfer accuracy was significantly higher with IOSs than with CAIs (p < 0.05). No such difference was found regarding the six angles. In patients with MBAs, digital impression-taking using IOSs can be recommended. For all measured variables except one, the transfer accuracy of IOSs was better than or at least equivalent to the data from CAIs. In addition, significantly (p < 0.001) less time was necessary for all IOSs in comparison to CAIs plus plaster casting.

The transfer accuracy of digital and conventional full-arch impressions influenced by fixed orthodontic appliances: a reference aid–based in vitro study

ObjectivesThe aim of this in vitro study was to investigate the influence of fixed orthodontic appliances (FOAs) on the transfer accuracy of full-arch impressions by five intraoral scanners (IOSs): CS3600, Primescan, Trios 4, Medit i500, Emerald S, and one conventional alginate impression (CAI).Materials and methodsTo compare the data with the actual model situation, an established reference aid–based method was applied. A test model with human teeth was used and modified for each testing group, resulting in five different settings: natural teeth (group A), metal brackets without/with wire (groups B/C), ceramic brackets without/with wire (groups D/E). A total of 300 (n = 12 × 5 × 5) scan datasets of IOSs were analyzed using a 3D software (GOM Inspect) and 60 (n = 12 × 5) plaster casts of CAI were measured with a coordinate measurement machine. The deviations between the reference aid and the impressions were determined.ResultsFor all groups with brackets (B to E), IOSs showed a higher transfer accuracy compared to CAI, even for long-span distances. However, some significant differences between the IOSs were observed (p < 0.05).ConclusionsWithin the limitations of this in vitro study, IOSs can be recommended for impressions with and without FOAs, even if CAI showed the smallest average deviations in settings without FOAs.Clinical relevanceIOSs are widely used in orthodontics and the current study demonstrated that their use enables fast impression taking even in settings with fixed orthodontic appliances. In addition, for these settings, the transfer accuracy is higher than with conventional alginate impressions. Nevertheless, a re-investigation in a clinical setting should be performed to verify the current in vitro findings.

Digital Intraoral Scanners and Alginate Impressions in Reproducing Full Dental Arches: A Comparative 3D Assessment

The purpose of this in vivo study was to compare in vivo full arch intraoral scans obtained using two intraoral scanners and conventional impression. Twenty patients were scanned using TRIOS and iTero scanners, as well as conventional impression. Dental models obtained from alginate impression were scanned with a laboratory desktop scanner. Individual intraoral scan data were compared with corresponding model scans using three-dimensional (3D) surface analysis. The average surface deviations were calculated for quantitative evaluation, and these values were compared between two intraoral scanners using the paired t-test. In the 3D surface analysis, most deviations between intraoral scans and model scans presented on the posterior teeth. The average surface deviations were less than 0.10 ± 0.03 mm. The results of 3D surface analysis indicated that there was 0.10 mm of overall deviation between conventional alginate impressions and in vivo full dental arch intraoral scans. Clinicians should take this into consideration when performing intraoral scanning for full dental arches.

Accuracy of intraoral scans in the mixed dentition: a prospective non-randomized comparative clinical trial

ObjectiveIn-vivo accuracy of intraoral scans of complete mixed dentitions of patients in active treatment have not yet been investigated. The aim was to test the hypothesis that dimensional differences between intraoral scans and conventional alginate impressions in the mixed dentition are clinically irrelevant.MethodsTrial design: Prospective non-randomized comparative clinical trial. Based on sample size calculation 44 evaluable mixed dentition jaws of patients in active orthodontic treatment were included. Each patient received an alginate impression following an intraoral scan (TRIOS® Ortho). Plaster cast was fabricated and scanned with an external scanner (ATOS-SO®). Both STL datasets were analyzed with the 3D inspection and mesh processing software GOM Inspect®. Statistical analysis comprised sample size calculation, t-test as well as nonparametric tests.ResultsThe absolute mean difference between digital plaster casts and intraoral scans is 0.022 mm ± 0.027 mm (median 0.015 mm). The obtained measurements are in the range of comparable studies on full arch permanent dentitions. Gender, the size of the jaw represented by the dentition stage and upper respectively lower jaw, as well the malocclusion have no effect on the total deviations between digital plaster casts and intraoral scans. Detectable impression errors were bubbles in fissures and marginal ridges as well as incomplete alginate flow and detachment from the tray. Detectable scanning errors were incomplete distal surface of the most distal molar.ConclusionDimensional differences between intraoral scans and conventional alginate impressions in the mixed dentition are clinically irrelevant for orthodontic purposes. In all clinical situations of active treatment in the mixed dentition, the intraoral scans are more detailed and less error-prone.

Is It Cost Effective to Add an Intraoral Scanner to an Oral and Maxillofacial Surgery Practice?

Intraoral scanners (IOSs), which create digital "impressions" of dental arches, have become popular for prosthetic and orthodontic applications. Adoption in oral and maxillofacial surgery (OMS) practices has been slower, likely because of high implementation costs and low-volume use. The purpose of this study was to evaluate costs for introduction of an IOS into an OMS practice. The authors hypothesized that digital impressions would be more efficient in time and cost compared with conventional impressions and that implementation costs would be offset within 1year. This was a prospective study that included patients who had digital impressions during the first year after introduction of an IOS to the practice. Conventional alginate impressions obtained at the same visit were included for comparison. Variables included time for each step in each impression process, IOS experience of the operator obtaining the impression, and associated costs. Per-arch costs for each technique were calculated using time-driven activity-based costing methodology. Sixty-three digital impressions and 31 conventional impressions were included. Mean total times for digital and conventional impressions were 14.1±1.3 and 19.4±4.0minutes per arch, respectively. On a per-patient basis (2 arches for digital impressions and 4 arches for conventional impressions because of the inability to create duplicate stone models from each alginate impression), total impression times were 24.8±2.7minutes for digital and 67.2±14.8minutes for conventional impressions. Total calculated costs for digital and conventional impressions were $21.42 and $29.40 per arch and $37.66 and $102.10 per patient, respectively. In a practice with 2 patients for impressions per working day (500 per year), it would take 1.04years to offset the purchase of the IOS; with 5 sets of impressions per day (1,250 per year), it would take 5months. Digital impressions are more efficient and cost effective than standard impressions, and implementation costs can be offset within the first year.

A novel in vivo method to evaluate trueness of digital impressions

BackgroundIntraoral scanners are devices for capturing digital impressions in dentistry. Until now, several in vitro studies have assessed the trueness of digital impressions, but in vivo studies are missing. Therefore, the purpose of this study was to introduce a new method to assess trueness of intraoral scanners and digital impressions in an in vivo clinical set-up.MethodsA digital impression using an intraoral scanner (Trios® 3 Cart wired, 3Shape, Copenhagen, Denmark) and a conventional alginate impression (Cavex Impressional®, Cavex, Haarlem, the Netherlands) as clinical reference were made for two patients assigned for full mouth extraction. A total of 30 teeth were collected upon surgery after impressions making. The gypsum model created from conventional impression and extracted teeth were then scanned in a lab scanner (Activity 885®, SmartOptics, Bochum, Germany). Digital model of the intraoral scanner (DM), digital model of the conventional gypsum cast (CM) and those of the extracted natural teeth (NT) were imported to a reverse engineering software (3-matic®, Materialise, Leuven, Belgium) in which the three models were registered then DM and CM were compared to their corresponding teeth in NT by distance map calculations.ResultsDM had statistically insignificant better trueness when compared to CM for total dataset (p = 0.15), statistically insignificant better trueness for CM when mandibular arches analyzed alone (p = 0.56), while a significantly better DM trueness (p = 0.013) was found when only maxillary arches were compared.ConclusionsOur results show that digital impression technique is clinically as good as or better than the current reference standard for study models of orthognathic surgery patients.

Comparison of digital intraoral scanners and alginate impressions: Time and patient satisfaction.

Recent technological advances have made intraoral scans and digital models a possibility and a promising alternative to conventional alginate impressions. Several factors should be examined when considering an intraoral scanner, including patient acceptance and efficiency. The objectives of this study were to assess and compare patient satisfaction and time required between 2 intraoral scanners and conventional alginate impressions. An initial pilot study was completed to create a valid and reliable survey instrument that would measure 3 areas of patient satisfaction with the impression experience. A visual analog scale survey was developed and administered to 180 orthodontic patients receiving 1 of 3 types of impressions: (1) iTero Element intraoral scan (Align Technologies, San Jose, Calif), n=60; (2) TRIOS Color intraoral scan (3Shape, Copenhagen, Denmark), n=60; and (3) conventional alginate impression (imprEssix Color Change; Dentsply Sirona, York, Pa), n=60, and the time required to obtain the impressions was recorded. Reliability was evaluated with intraclass correlation coefficient values for 17 paired questionnaires, and all questions were found to be reliable (intraclass correlation coefficient, ≥0.65). For the main study, 180 subjects completed timed impressions and surveys. Data indicated that subjects receiving intraoral scans preferred the digital impressions, and subjects receiving alginate impressions were neutral regarding impression preference, and that efficiency varied based on the impression method. Intraoral scanners are accepted by orthodontic patients, and they have comparable efficiency with conventional impression methods depending on the type of scanner.

Comparison of two intraoral scanners based on three-dimensional surface analysis

BackgroundThis in vivo study evaluated the difference of two well-known intraoral scanners used in dentistry, namely iTero (Align Technology) and TRIOS (3Shape).MethodsThirty-two participants underwent intraoral scans with TRIOS and iTero scanners, as well as conventional alginate impressions. The scans obtained with the two intraoral scanners were compared with each other and were also compared with the corresponding model scans by means of three-dimensional surface analysis. The average differences between the two intraoral scans on the surfaces were evaluated by color-mapping. The average differences in the three-dimensional direction between each intraoral scans and its corresponding model scan were calculated at all points on the surfaces.ResultsThe average differences between the two intraoral scanners were 0.057 mm at the maxilla and 0.069 mm at the mandible. Color histograms showed that local deviations between the two scanners occurred in the posterior area. As for difference in the three-dimensional direction, there was no statistically significant difference between two scanners.ConclusionsAlthough there were some deviations in visible inspection, there was no statistical significance between the two intraoral scanners.

Clinical comparison of conventional and additive manufactured stabilization splints

The aim of this study was to compare conventional and digital additive manufacturing of hard occlusal stabilization splints (SS) using technical and clinical parameters. 14 subjects were subjected to DC/TMD Axis I clinical examination protocol and Axis II questionnaire. The subjects underwent treatment with splints over a period of 12 weeks. All subjects underwent both conventional alginate impression and intraoral digital scanning. Seven subjects received conventional manufactured stabilization splints (CM-SS), and seven subjects received CAD-CAM additive manufactured stabilization splints (AM-SS). 12 subjects completed the 12 weeks follow-up period. The subjects significantly preferred digital intraoral scanning compared to conventional alginate impression. There was a significant difference in VAS between CM-SS and AM-SS. The mean VAS result was 15 for AM-SS and 42 for CM-SS, 0 represented excellent comfort and 100 very uncomfortable. This was significant. Splint manufacturing method had no influence on treatment outcome. There was no significant difference in mean delta change for unassisted jaw opening from baseline to 12 weeks between the two groups, for CM-SS it was 2 mm difference and for AM-SS the difference was 3 mm. All subjects in both treatment groups showed improved oral function. In this study, the scanning procedure is more accepted by the subjects than alginate impressions, however the first procedure was more time consuming.

Comparative evaluation of anticandidal activity of pre-incorporated quaternary ammonium compound disinfectant alginate with 5.25% sodium hypochlorite spray disinfectant on the conventional alginate: An In Vivo study

ContextA lot of research and literature exists regarding the methods of disinfecting alginates; however, there is still need for a infallible, quick, and standardized method, which can be used as chair side disinfectant for alginate impressions in patients with candida related denture stomatitis. AimAn In Vivo study was undertaken to evaluate the anticandidal activity of pre-incorporated quaternary ammonium compound disinfectant in the alginate with conventional alginate impression material disinfected with 5.25% sodium hypochlorite spray (1min) in primary impressions of completely edentulous patients with denture stomatitis. Methods and materialGroup 1 consisted of 10 conventional alginate (Imprint) impressions disinfected by 5.25% sodium hypochlorite spray for 1min. Group 2 consisted of 10 pre-incorporated quaternary ammonium compound alginates (Jeltrate Plus). Totally, 20 swabs (10 per group) were collected from palatal concavities of primary impressions and inoculated on Sabouraud GC Agar media at 37°C for 24–96h. Digital colony counter was used for counting colony-forming units (CFU). Statistical analysis usedThe data analysis was done using descriptive statistics and independent t-test. ResultsAccording to p value (p<0.01), there was a statistical significant difference in mean values of the two groups. Group 1 showed significant anticandidal activity in comparison to Group 2. ConclusionsAccording to limitations of this In Vivo study, sodium hypochlorite (5.25% for 1min) spray disinfectant is more clinically effective as compared to the pre-incorporated quaternary ammonium compound alginate for patients with denture stomatitis.

Tooth width measurement using the Lythos digital scanner

Abstract Introduction Digital models have become more widely accepted for orthodontic diagnostic purposes. Intraoral scanners have the advantage of eliminating the need for conventional impressions. The aim of the present study was to assess the reliability and reproducibility of the Lythos intraoral scanner and to determine if a significant advantage is delivered over stone model and caliper measurements in tooth width and Bolton ratio accuracy. Methods The study comprised 30 typodont models for which conventional alginate impressions and digital scans were obtained to generate stone and digital models, respectively. Mesiodistal tooth width measurements and Bolton ratios were obtained with either calipers and stone models or with Digicast (Ormco Lythos digital model software, Ormco, CA, USA) software using digital models. Pearson’s correlation coefficients tested intra-examiner reliability. Interclass correlation coefficients were used to assess agreement between examiners (reproducibility). The differences in the mean tooth width measurements and Bolton ratios from the typodont values and either the digital or conventional method were used to assess validity by applying two tailed t-tests. Results The measurements obtained from the Lythos and stone models had near perfect intra-examiner agreement (Pearson ≥ 0.98). The inter-examiner reproducibility for tooth widths, anterior Bolton and overall Bolton ratio was high and similar for both methods (Lythos scanner Interclass correlation coefficient (ICC) above 0.89, stone models ICC above 0.92). Stone model measurements were statistically twice as accurate as those derived from the digital system (0.032 mm versus 0.074 mm). There were no significant differences in accuracy between the methods for Bolton calculations. Clinically, there was no difference between the methods for tooth width measurements and Bolton calculations. Conclusions The Lythos system is as reliable and reproducible as conventional calipers and stone models in tooth width measurements and Bolton calculations. The caliper method presents a statistically more valid tooth width measurement technique but the clinical significance of this is questionable.

Simultaneous Virtual Planning Implant Surgical Guides and Immediate Laboratory-Fabricated Provisionals: An Impressionless Technique.

Abstract Since the emergence of dental implants as treatment modality, there has been a constant evolution to improve the accuracy, efficiency and long term success even in the most complicated cases. In this day and age, patient's expectations are higher than ever to achieve their desired treatment in a prompt and convenient manner. To meet these expectations implant therapy has grown to be highly sophisticated. For the past decade, computed tomography (CT) scans have been utilized to improve the treatment planning process. Further more they have been used to fabricate surgical guides, making implant placement not only more accurate but also safer. On the other hand, advancements in the implant prosthetics now have made immediate restorations more feasible. This article reviews two cases, where dental implants are based through a CT fabricated surgical guide, and immediately restored with a lab fabricated screw retained bridge. This novel technique utilizes intraoral digital scanner instead of the conventional alginate impression and combines the electronic data with the CT images to fabricate both the surgical guide and the immediate provisional restoration.

Analysis of the linear dimensions of the high stability alginate cast models with casting delays

Introduction: Dimensional stability of alginate impression is important to obtain an accurate cast. This study was to find the linear dimensional changes of the cast made from delayed pour high stability alginate impression after 5 days. Methods: This experimental laboratory study used 20 samples, divided into 4 groups. First and third group were the generated cast produced by immediately pour into high stability and conventional alginate impressions. Second and fourth group were the generated cast produced by delayed pour into high stability and conventional alginate impression for 5 days in storage with 100% humidity. Dimensional changes were measured on the upper part of the cast from buccal-lingual and mesial-distal direction beside measuring on the outer distance between the upper cast used Mitutoyo digital caliper scaled 0.01 mm. The data were analyzed using ANOVA (α = 0.05).Results: Mesial-distal (a) diameter average of group I, II, IV were respectively 8.410 mm, 8.520 mm, and 8.620 mm, compared with III as control was 8.420 mm. Meanwhile, diameter averages of mesial-distal (b) were 8.314 mm, 8.416 mm, 8.513 mm, and 8.315 mm. The averages of distance between each teeth (c) were 13.312 mm, 13.240 mm 13.191 mm, and 13.316 mm. The diameter averages of buccal-lingual (d) were 8.411 mm, 8.530 mm, 8.608 mm and 8.410 mm. The diameter averages of buccal-lingual (e) were 8.350 mm, 8.441 mm, 8.524 mm, and 8.340 mm. ANOVA test of the results of distance measurements between teeth (c) produces a calculated F value of 147.850, higher than the F table value (3.239). There were significant diferencess dimensional changes on gypsum cast made from high stability alginate impression and then poured after 5 days. Conclusion: There were diferencess linier dimensional changes on gypsum cast made from high stability alginate impression and then poured after 5 days.

How fast are your alginate impressions cast?

Dental UpdateVol. 38, No. 7 AbstractsHow fast are your alginate impressions cast?Peter CarrottePeter CarrotteSearch for more papers by this authorPeter CarrottePublished Online:20 Jun 2017https://doi.org/10.12968/denu.2011.38.7.470AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail View article References Accuracy and dimensional stability of extended-pour and conventional alginate impression materials. Imbery TA, Nehring J, Janus C and Moon PC. J Am Dent Assoc 2010; 141: 32–39. Medline, Google Scholar FiguresReferencesRelatedDetails 2 September 2011Volume 38Issue 7ISSN (print): 0305-5000ISSN (online): 2515-589X Metrics History Published online 20 June 2017 Published in print 2 September 2011 Information© George Warman Publications (UK) LimitedPDF download

Accuracy and dimensional stability of extended-pour and conventional alginate impression materials

The authors conducted a study to determine if two irreversible hydrocolloid impression materials (Cavex ColorChange, Cavex Holland BV, Haarlem, Netherlands; Jeltrate Plus Antimicrobial Dustless Alginate Impression Material, Dentsply Caulk, Milford, Del.) stored for five days were dimensionally accurate. The authors modified Ivorine teeth (Columbia Dentoform, Long Island City, N.Y.) on a Dentoform model (1560 series model, Columbia Dentoform) to allow measurements of tooth and arch width. They made impressions and generated casts immediately and at five additional times. They recorded tooth and arch widths on the casts and compared the measurements with those for the standard model. Compared with measurements for the model, the greatest measured difference in casts was 0.003 inches for Cavex ColorChange (extended-pour alginate) and 0.005 inches for Jeltrate Plus Antimicrobial Dustless Alginate Impression Material (conventional alginate). The percentage of dimensional change ranged from -0.496 to 0.161 percent for the extended-pour alginate and from -0.174 to 0.912 percent for the conventional alginate. Results of analysis of variance and paired t tests indicated that when generated immediately and at day 5, casts produced from both impression materials were not statistically different from the standard model (P < .05). When stored properly, both alginate materials can produce accurate impressions at day 5 for diagnostic casts and for fabrication of acrylic appliances.