Oral Impression Research Articles

Use Of Digital Technologies In Prosthodontic Clinical Practice Among Prosthodontists In Tamilnadu And Pondicherry

Background: Digital dentistry includes treatments performed by means of digital or computer-controlled components rather than using mechanical or electrical equipment. The advancement of digital technology and the commencement of Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) and 3D printing has brought large changes to the traditional manufacturing method, where manual work is carried out after oral impression taking. Aim: To conduct a questionnaire survey on use of digital technology in prosthodontic clinical practice among Prosthodontists in Tamilnadu and Pondicherry. Materials and methods: A cross-sectional questionnaire based online survey was undertaken amongst 183 Prosthodontists in Tamilnadu and Pondicherry (Group 1 – Both private practitioners and teaching faculty, Group 2 – Private practitioners, Group 3 – Teaching faculty). The questionnaire consisted of 21 questions which evaluated their awareness, knowledge and practices towards digital dentistry. Statistical analysis was done using Chi-square test in each group, using Statistical Package for the Social Sciences (SPSS) version 23.0. The p-value 0.05 was considered significant. Results: Majority of the study participants were private practitioners in the age group of 25 – 45 years(93%).Among the three groups private practitioners had good knowledge, practice and awareness about the application of digital technologies. Conclusion: Most of the participants were aware about digital technology in dentistry. The private practitioners showed better understanding about the digital technology. However, to make them familiar with CAD/CAM, dental education programs, workshops and hands on program should be conducted which will enable an emerging dentists who will be well versed with digital dentistry.

Riabilitazione implanto-protesica utilizzando lo scan-analog protocol: un caso clinico

Objectives: A digital workflow for prosthetic implant rehabilitation can start either from intraoral scans or from the scan of the patient cast models. However, the possibility of scanning oral impressions is little considered and evaluated in implant prosthodontics. The elimination of pouring cast models with scannable impression materials could bring advantages especially in implant-prosthodontics, because … Continued

The Compliance of Dentists toward Prescribing Prophylaxis Antibiotic for Special Care Patients at Risk of Having Infective Endocarditis

Background: Prescribing antibiotics (Abs) as a prophylactic before dental procedures is recommended by the American Academy of Pediatric Dentistry (AAPD) in patients with cardiac diseases to prevent a potentially life-threatening infection of the cardiac valves or endocardium called “infective endocarditis (IE).” Aim: This study aimed to assess the compliance of dentists in Makkah city with the AAPD recommendations of prescribing prophylaxis Abs for special care pediatric patients at risk of having IE. Materials and Methods: This was an observational cross-sectional study among dentists who are working at the major hospitals in Makkah city, Saudi Arabia. Participants' perception regarding the prescription of prophylactic Abs was measured using validated and reliable questions. The reliability analysis was used with a model of alpha (Cronbach) to study the properties of measurement scales and the items that compose the scales and the average inter-item correlation. Results: One hundred and thirty-two dental practitioners were participated. Dental care providers would prescribe Abs with dental extraction (92.4%), periodontal surgery (89.4%), nonsurgical root canal treatment beyond apex (77.3%), supragingival scaling (67.4%), and retraction cord placement (46.2%). On the other hand, dental practitioners would not prescribe Abs for orthodontic appliance (87.9%), intraoral radiograph (87.1%), primary teeth shedding (81.8%), tooth preparation when taking an oral impression (76.5%), local anesthesia infiltration (68.2%), and restoration of Class II caries with matrix and wedge (56.8%). A significantly lower knowledge score was obtained by general dental practitioners when compared with consultant and specialists (P = 0.044). Consultants and specialists recorded significantly lower knowledge on the prescription of prophylaxis Abs for Class II caries with matrix and wedge (P < 0.001) when compared with general dental practitioners. Conclusions: Most dentists followed the AAPD recommendations of prophylactic Abs for children who have a high risk of developing IE. However, Class II dental restorations with matrix and wedge and placement of retraction cord have recorded more invalid responses. General dental practitioners had lower knowledge when compared with consultants and specialists when prescribing Abs for children who have a high risk of developing IE.

Modified impression technique for extreme mouth-opening limitation caused by systemic scleroderma.

Systemic scleroderma is a relatively rare, autoimmune, chronic, and debilitating disease, and its etiology is unknown. The disease is characterized by vasomotor disturbances causing skin and mucosa hardening, hand stiffness, excess production of collagen fibers, and impairment of the internal organs associated with the immune system. Extreme mouth-opening limitation is one of the symptoms in the oral cavity, and compromises dental intervention. One of the fundamental steps when performing a dental procedure is dental arch impression. In the presented clinical case, limited mouth opening hindered the impression accuracy. The objective was to present an alternative impression technique for a patient affected by scleroderma, with limited mouth opening and the need for oral rehabilitation with a removable partial prosthesis in the maxillary arch. An individualized tray was developed with design characteristics that allowed access to the oral cavity and removal, after which it was possible to perform the oral impression, reproducing the areas of interest without causing injury to the oral tissues. The orientation plan was elaborated after obtaining the cast. The teeth were assembled, tested in the mouth, and sent to the laboratory for acrylization. The prosthesis was placed once ready. The alternative impression technique enabled oral rehabilitation of the patient despite the mouth-opening limitation, and provided an accurate impression and a good prosthetic result.

Evaluation of the influence of the impression technique, scanning direction and type of scanner on the accuracy of the final model

Objective: The purpose of this study is to evaluate the influence of the type of scanner and scanning direction on the accuracy of the final cast. Material and Methods: A partial master cast was used as a reference. A total of 128 scans were obtained and divided into two groups: the conventional method and the digital method. The digital group was divided into three groups: TRIOS 3, Omnicam and CS 3600. Each of these groups was subdivided according to the scanning direction, and each scan was overlaid on the digital reference cast to measure the trueness and precision of the procedures. Results: The overall precision values for the type of impression were 59.89 ± 13.08 mm for conventional and 13.42 ± 4.28 mm for digital; the values for trueness were 49.37 ± 19.13 mm for conventional and 53.53 ± 4.97 mm for digital; the scanning direction trueness values were 53.05 ± 4.36 mm for continuous and 54.03 ± 5.52 mm for segmented; and the precision values were 14.18 ± 4.67 mm for continuous and 12.67 ± 3.75 mm for segmented (p> 0.05). For the scanner type, the trueness values were 50.06 ± 2.65 mm for Trios 3, 57.45 ± 4.63 mm for Omnicam, and 52.57 ± 4.65 mm for Carestream; and those for precision were 11.7 ± 2.07 mm for Trios 3, 10.09 ± 2.24 mm for Omnicam, and 18.49 ± 2.42 mm for Carestream (p <0.05). Conclusions: The digital impression method is the most favorable method regarding precision; in terms of trueness, there are no differences between the types of impressions. KEYWORDS Conventional impression; Intra oral impression; Accuracy; Trueness.

Clinical Study Comparing The Internal Adaptation And Marginal Fit Of All-Ceramic Zirconia Fixed Restorations Obtained From Conventional And Digital Intra oral Impression Techniques. (Randomized Controlled Clinical Trial)

Clinical Study Comparing The Internal Adaptation And Marginal Fit Of All-Ceramic Zirconia Fixed Restorations Obtained From Conventional And Digital Intra oral Impression Techniques. (Randomized Controlled Clinical Trial)

Semi-Fixed Lip Bumper in Lesch-Nyhan Syndrome: An Interim Treatment Modality

Lesch-Nyhan syndrome is a rare X-linked, recessively inherited disorder of purine metabolism, caused by complete absence of the enzyme hypoxanthine-guanine phosphoribosyl transferase. This syndrome is characterized by 3 major features: neurological dysfunction, hyperuricemia, and cognitive and behavioral disturbances (e.g., self-mutilation, which begins at 2 to 3 years of age). Uncontrollable self-mutilation begins with biting of the perioral tissues and extends into patterns such as finger biting and head hitting. This report describes the case of a 31-month-old boy who was diagnosed with Lesch-Nyhan syndrome with severe lip injuries caused by self-mutilative behaviors. The behaviors were blocked with a semi-fixed lip bumper for a short period. The device was applied to the patient on the day of the visit without the requirement for an oral impression. It was easy to manage oral hygiene and adjust the device because it was detachable by clinicians and guardians. Therefore, a semi-fixed lip bumper may be useful as an interim appliance to block self-mutilative behaviors in children with Lesch-Nyhan syndrome.

Computerized optical impression making of edentulous jaws – An in vivo feasibility study

PurposeWithin the specialty of prosthodontics, oral impressions are ubiquitous tools utilized to transfer intraoral characteristics such as teeth, implants, and soft tissue into a physical state (stone cast) that is processable in a laboratory setting for the fabrication of dental restorations. In recent years, optical impression systems have become ubiquitous in clinical practice replacing the conventional method of impression making. The purpose of the present study was to evaluate the feasibility and accuracy of computerized optical impression making of edentulous jaws in an in vivo setting. Methods29 edentulous patients (27 maxillae and five mandibles) underwent conventional impressions as well as computerized optical impressions. The conventional impressions and the resulting stone casts were digitized and superimposed over the computerized/digitized optical impressions in order to obtain information on differences between the two datasets. Statistical analyses were performed to identify relevant deviations. ResultsThe overall mean difference between the stone cast, digital scans and the computerized optical scans were 336.7 ± 105.0 µm (n = 32), 363.7 ± 143.1 µm (n = 24), and 272.1 ± 168.5 µm (n = 29), respectively. The visual evaluations revealed highest deviations (≥ 500 µm) in the areas of the soft palate, the sublingual areas, and the vestibule (peripheral seal zone). ConclusionsWithin the limitations of the present study, the investigated scanners were not able currently to fully replace a conventional impression for the fabrication of a complete denture.

Evaluation of a Digital Protocol for Pre-Surgical Orthopedic Treatment of Cleft Lip and Palate in Newborn Patients: A Pilot Study.

The aim of this study was to evaluate the accuracy, invasiveness and impact on clinical results of a digital oral impression protocol in the pre-surgical orthopedic treatment (PSOT) of newborn cleft lip and palate (CLP) patients undergoing primary alveolar surgical repair. Six patients were divided, according to impression technique used, into a digital (intraoral scanner (IOS)) and a non-digital (tray and putty (T&P)) group. Parents considered IOS impressions to be less invasive, compared to T&P impressions. The clinician that took all the impressions considered the IOS to be less stressful compared to the T&P method. In two T&P patients, the impression was repeated because some important anatomical details were missing, in one case due to patient regurgitation during the first attempt. No impression was repeated, and any adverse event was reported in the IOS group. There were no significant differences between these two protocols in pre-surgical alveolar gap reduction and surgical challenge. The study results indicate that this digital protocol can accelerate the production process of the passive molding plate with an instantaneous transmission of the digital impression to the dental lab, maintaining the same accuracy level and clinical outcomes of classical techniques and reducing the invasiveness of impression taking, avoiding any risk of impression material ingestion or inhalation.

Milled versus moulded mock-ups based on the superimposition of 3D meshes from digital oral impressions: a comparative in vitro study in the aesthetic area

BackgroundAesthetic porcelain veneers proved to be a long-term reliable prosthetic solution, ensuring minimal invasiveness. The use of veneers requires an adhesive cementation technique, so maintaining as much enamel as possible is to ensure lasting success. A diagnostic mock-up is a key tool that allows a preview of the outcome of the aesthetic restoration: it is obtainable both in an analog and digital way. With the recent developments in impression technology and the ever so fast growing use of CAD-CAM technologies it is useful to understand the pros and cons of either one of these techniques (analog and digital) in order to identify the easier and more convenient workflow in aesthetic dentistry.MethodsAfter taking pictures and impressions of the dental arcs of a patient in need of aesthetic rehabilitation, 52 resin models were produced and a digital drawing of the smile was outlined. Both an analog and a digital wax-up were obtained from two of the 52 models: the latter was obtained using digital impressions and a dedicated software. The analog wax-up was then used to produce 25 matrices that have later been used to mould 25 resin mock-ups using a traditional moulding protocol (Control Group - CG). The digital wax-up was used to mill 25 PMMA mock-ups. Each mock-up, both milled and moulded (total 50), was then laid on the other 50 resin models as a digital impression of it was taken. The STL. files of the milled mock-ups were compared with the 3D CAD wax-up made using a specific software. The STL. files of the analog printed mock-ups were compared with the traditional wax-up design. A statistical analysis was carried out to evaluate the difference between the groups.ResultsThe statistical analysis showed a significant difference (P > 0.01) between the mean value of the distance between the points of the overlapping STL. meshes in GC (0.0468 mm) and in TG (Test Group - TG) (0,0109 mm).ConclusionsThe study showed a difference in accuracy between traditional moulded and milled mock-ups compared to their original wax-up. The data analysis reports that the digital method allows for greater accuracy. Within the limitations of this study, a fully digital workflow is to considered more reliable when it come to creating an esthetic mockup: the digital procedure has been shown to be more accurate than the one made manually which is much more operator dependent and it brings an increase to the chance of error, and that could ultimately affect the final result.

Presurgical Nasal Molding With a Nasal Spring in Patients With Mild-to-Moderate Nasal Deformity With Incomplete Unilateral Cleft Lip With or Without Cleft Palate.

Traditional nasoalveolar molding (NAM) requires steep learning curve for clinicians and significant compliance from parents. Nasal springs have been developed by the author to simplify presurgical nasal molding. This article presents the design, construction, and application of the spring. The treatment goal is to improve nasal deformity prior to primary repair in infants born with incomplete unilateral cleft lip with or without cleft palate. The design, fabrication, and utility of the nasal spring are described. The spring has a simpler design and construction compared to a traditional NAM appliance. Two patients with incomplete unilateral cleft lip with and without cleft palate are presented. The spring is constructed and delivered. The active arm of the spring can be 3-dimensionally (3-D) adjusted to mold the alar cartilage of the affected nostril. The spring does not require an oral plate for adherence as a traditional NAM appliance does, hence an oral impression is not needed. The spring is easy for clinicians to adjust. It also requires less compliance by parents. The presurgical molding achieved by the use of a nasal spring improved surgical nasolabial aesthetic outcomes. The nasal springs are effective in reducing the initial cleft nasal deformity. This facilitates primary surgical cleft lip and nose correction and improves surgical outcomes in patients with incomplete unilateral cleft lip with or without cleft palate.

The Effect of Pungent and Tingling Compounds from Piper nigrum L. on Background K+ Currents.

Black peppercorns (Piper nigrum L.) elicit a pungent and tingling oral impression. Their pungency is partially explained by the agonist activity of some of their active principles, especially piperine, on TRP channels. However, we recently showed that piperine, as well as other pungent compounds, also possess a marked effect on two-pore domain (KCNK, K2P) K+ channels. Members of this family play a key role in maintaining the resting membrane potential of excitable cells. Interestingly, tingling compounds have been shown to induce neuronal excitation by inhibiting KCNK channels. We addressed the question of whether it was plausible that KCNK channels could constitute a physiologically relevant target for the sensory active compounds present in black peppercorns. Because previous studies have demonstrated that mouse trigeminal neurons respond to several pungent compounds, to which humans are also sensitive, we used a primary culture of mouse trigeminal neurons to investigate whether the effect of piperine on these cell types could also be mediated by KCNK channels. We observed that even in the presence of classical TRP-antagonists, piperine was still able to activate a fraction of trigeminal neurons. Furthermore, our results showed that piperine is capable of inducing neuronal depolarization by a mechanism that does not require extracellular Na+ or Ca2+. This depolarization was mediated by the inhibition of a background K+ conductance, most likely corresponding to the KCNK channels of the TASK subfamily. We then performed a screening with 12 other pungent and/or tingling chemosensates isolated from black peppercorns. These compounds were evaluated on Xenopus laevis oocytes expressing the human orthologues of KCNK3, KNCK9 and KCNK18, which we previously showed to be inhibited by piperine. Remarkably, almost all of the isolated chemosensates inhibited the basal activity of hKCNK3, with 1-(octadeca-2E,4E,13/12Z-trienoyl)pyrrolidine acting as one of the most potent natural blockers for hKCNK3 found to date. Our results suggest that KCNK channels, especially KCNK3, are likely to play a complementary role to TRP channels in the complex orosensory impression elicited by black peppercorns, while they also help to expand the pharmacological knowledge of KCNK channels.

Multimedia patient education to assist oral impression taking during dental treatment: A pilot study

IntroductionProper cooperation between patient and dentist is of great help to make a good oral impression. However, patients are frequently confused when information is given through traditional verbal description. The present study compared the effectiveness of the multimedia information delivery ways with the traditional verbal manner on patients’ understanding level in oral impression taking. MethodsThe recruited 191 participating patients were randomly assigned to the control group (the verbal group) and two intervention groups (the video group and the picture group) according to the information delivery manner. After intervention, the patients’ understanding degree was measured by questionnaire and performance evaluation of behavior feedback on the provided information quantitatively. Also, patients’ self-assessment of satisfaction was interviewed by telephone. All data was analyzed by SPSS 14.0 software, and p≤0.05 was set as significant difference in advance. ResultsOne-Way ANOVA and Chi-square showed there were no statistically significant differences in the mean age, gender composition, and educational level among the three groups (P>0.05). In both questionnaire assessment and performance evaluation, One-Way ANOVA followed by LSD indicate that the video group gained a higher score than the verbal group or the picture group (P<0.05). The questionnaire score in the picture group is significantly higher than in the control group (P<0.05), but no significant difference was shown between these two groups in patients’ performance evaluation (P>0.05). Higher percentage of satisfaction was reported by patients in the two multimedia groups than that in the control group. DiscussionOral impression taking is a consecutive process that requires action cooperation between dentists and patients simultaneously. This particularity makes it more suitable for multimedia delivery. The delivery of tailored information using multimedia in this study was favored by most patients and could improve the degree of patient understanding of the oral impression taking procedures.

Dentistry in nasal reconstruction

Introduction: Popularity of aesthetic nasal surgery is testament to the importance patients place on the cosmetic appearance of the nose. Some nasal defects following tumour surgery require a Rhinectomy or partial Rhinectomy. Nasal defects can have significant psychological and functional morbidity. There are various surgical options for reconstruction of nasal defects. There a variety of reconstructive methods including prosthetic. Dentists are used to taking intra oral impressions. We used this expertise to reconstruct patient specific splints.

Structural and Sensory Characterization of Key Pungent and Tingling Compounds from Black Pepper (Piper nigrum L.)

To gain a more comprehensive knowledge on whether, besides the well-known piperine, other compounds are responsible for the pungent and tingling oral impression imparted by black pepper, an ethanol extract prepared from black pepper (Piper nigrum L.) was screened for its key sensory-active nonvolatiles by application of taste dilution analysis (TDA). Purification of the compounds perceived with the highest sensory impact, followed by LC-MS and 1D/2D NMR experiments as well as synthesis, led to the structure determination of 25 key pungent and tingling phytochemicals, among which the eight amides 1-(octadeca-2E,4E,13Z-trienyl)piperidine, 1-(octadeca-2E,4E,13Z-trienyl)pyrrolidine, (2E,4E,13Z)-N-isobutyl-octadeca-2,4,13-trienamide, 1-(octadeca-2E,4E,12Z-trienoyl)-pyrrolidine, 1-(eicosa-2E,4E,15Z-trienyl)piperidine, 1-(eicosa-2E,4E,15Z-trienyl)pyrrolidine, (2E,4E,15Z)-N-isobutyl-eicosa-2,4,15-trienamide, and 1-(eicosa-2E,4E,14Z-trienoyl)-pyrrolidine were not yet reported in literature. Sensory studies by means of a modified half-tongue test revealed recognition thresholds ranging from 3.0 to 1150.2 nmol/cm² for pungency and from 520.6 to 2162.1 nmol/cm² for the tingling orosensation depending on their chemical structure.

D-Bite (Digital-Bite): tecnica di costruzione CAD/CAM

Objectives To manufacture an occlusal splint based on CAD/CAM technology. Materials and methods Plaster casts made from oral impressions were scanned with CAD/CAM technology. The CAD/CAM device employed was a structured light-based scanner. CAD generates a 3D digital image that can be used to design the splint. During the CAM phase, the D-Bite (Digital Bite) was created from a block of polymethyl methacrylate (PMMA) with a thickness of about 20 mm. Results The production of a digitally designed D-Bite (Digital Bite). The D-Bite manufacturing technique is standardized thanks to computer-assisted procedures. Conclusions The D-Bite manufactured with CAD/CAM technology provided excellent biological and esthetic results, and the manufacturing technique was simple and rapid.

The effect of impression of the inherent deformation after adding the circular marker on oral impression

Objective To investigate the effect of impression of the inherent deformation after adding the circular marker on oral impression. Methods Two metal molds were made by American Dental Association standards. Six metal circular needles were inserted on one of molds. Two groups of impression sample which named A and B were made by two metal molds. Marker line on the impressions were measured and observed by measuring microscope to compare the impressions (group A and B) with the deformation extent and the deformation law. Croup t test method of SAS6.12 software was adopted to analyze the dimensional changes of the samples. Results The deformation range of two. groups( A and B) of alginate impressions was 0.38% ～ 0.58% and 0.43% ～ 0. 66%. Two groups of silicone impressions' deformation range was 0.38% ～ 0.42% and 0.33% ～ 0.49%. There was no significant difference between the two groups (P > 0.05 ). Conclusion The method with adding markers points on the oral impression would the impression of the inherent deformation. This marking method wag feasible. Key words: Dental impression technique; Location directories and signs; Odontometry

Dentists' knowledge and implementation of the 2007 American Heart Association guidelines for prevention of infective endocarditis

Our aim was to evaluate the knowledge and implementations of the 2007 American Heart Association guidelines for the prevention of infective endocarditis (IE) among practicing Israeli dentists, 12 months after their publication. A total of 118 dentists completed a questionnaire regarding required antibiotic prophylaxis for 10 specific cardiac patient subtypes before invasive dental treatment, prophylactic need in at-risk patients for IE in 10 dental procedures, and prophylactic regimen for nonallergic patients. Correct answer response for cardiac conditions was 81.3% (highest failure: mitral valve prolapse [MVP] with regurgitation). There was a consensus among the participants regarding antibiotic regimen for high-risk patients during several dental procedures, such as intraoral radiography, tooth extraction, and periodontal surgery, but a controversy for other procedures. The procedures of disagreement were endodontic treatment, tooth preparation with oral impressions, and restoration of class II caries lesion. Correct antimicrobial agent, dose, and timing were prescribed by 99%, 93.8%, and 100% of the respondents, respectively. Relatively high level of knowledge of the new guidelines was found among dentists, reflecting both familiarity of the practitioners with the guidelines and acceptance of guidelines. Prophylactic need is ambiguous during restorative, endodontic and prosthetic procedures. Educational resources should emphasize these guidelines, specifically the reduced risk level for MVP with regurgitation patients.

Techniques of cephalometry, photography, and oral impressions for infants

Techniques for collecting serial longitudinal data on young infant dental patients have been outlined. The data are primarily used to study the growth patterns of various structures of oral, facial, and cranial regions and are first collected during infancy. The data are collected biannually before the child is two years of age, and they are collected annually thereafter. The objective is to study the effects of various surgical procedures on the growth patterns of these regions.

Impression Materials: The Rationale of the Non-elastic Impression Materials

When utilizing the zinc oxide and eugenol pastes, it is necessary tor the operator to familiarize himself thoroughly with the physical and chemical properties and the indications and advantages before attempting the fabrication of an oral impression and the subsequent finished denture. When properly utilized, the zinc oxide and eugenol pastes are easily manipulated and produce dimensionally reliable impressions which consistently reproduce fine detail in full dentures, partial dentures, immediate dentures and relining service techniques. It is for these reasons that Temple University School of Dentistry has used the paste material for the past seven years in the Prosthetic Clinic.