Influence of Different Wax Hardening Agents on Surface Roughness of Refractory Cast Investment Materials

Background: Phosphate-bonded investments produce a refractory cast model with rough surface and undesirable properties. Dental Surface hardening agents are then applied to refractory investment materials to enhance its properties. Purpose: compare and evaluate the effects of different dental cast hardening agents (Bees wax, Carnauba wax, and Ceresin wax) on surface roughness of refractory model investment material. Approach: 30 specimens were constructed from commercially available phosphate bonded investment material. Specimens were subjected to a roughness test before dipping in handing agents, then divided into three groups according to the type of wax in which they were dipped. (10 specimens for each type). Surface roughness test was done by a profilometer where three readings were taken for all the specimens' surfaces randomly. The mean was then extracted for the roughness values before and after dipping in waxes. Results: the mean and standard deviation were tabulated and statistically analyzed using students T- test. The roughness values were decreased after the specimens were dipped in waxes (P value < 0.001 HS highly significant). Conclusion: The dipping process with hardening agents has significantly improved the surface roughness of the specimens' investment materials.

ORTHODONTIC TREATMENT FOR CONGENITAL CLEFT LIP AND PALATE IN CHILDREN

One in 1,000 newborns appears with a congenital maxillofacial anomaly, which accounts for about 0.04% of the world's entire population of the planet. Patients with cleft lip and palate have a significantly lower quality of life. Early orthodontic treatment (EOT) offered to children from the first days of life is a preparatory link in the preoperative period, laying favorable grounds for surgical intervention. EOT is a reasonable option to separate the oral cavity from the nasal cavity, to prevent consequent issues as well as to bring feeding back to the normal. This study involved clinical examinations and early orthodontic treatment of 84 children with congenital bilateral cleft upper lip and palate (CBCULP) from the first days of life and infants based on their referrals coming from all regions of the Republic of Tajikistan embracing the period of 2015 to 2019. Newborns with bilateral CULP within 5 days following birth, and infants who were referred for early orthodontic treatment, had their upper jaw cast model prepared using specially designed and modified spoons for taking impressions in case of cleft lip and palate. Within the study, unrelated marriages prevailed 3.4 times over related ones, which accounted for 22.6% of the cases examined. There were 1.58 times more boys than girls. Close relatives featured congenital maxillofacial abnormalities in 16.1% of the cases. The share of related marriages was 12.9%. Follow-up period — 2016–2017; the patients' age — from the birth period to 1 year. The children were divided into two groups. In the main group, EOT was performed using a dental obturator for orthodontic treatment of children with CBCULP prior to the surgery (n=43). In the comparison group, treatment was carried out in the conventional way (n=41). Before the surgery, all the children were examined through clinical, anthropometric and photometric methods. The statistical processing of the obtained data revealed that before the start of treatment, the studied groups were comparable with no statistically significant differences identified. After the treatment, the age, the weight, as well as the height of the children expectably changed in both groups (p<0.001).

Using the “One Shot” Concept for Immediate Loading Implant Protocol in Edentulous Patient Rehabilitation with a Fixed Prosthesis: A 6-Year Follow-Up

Immediate-loaded implants with a fixed prosthesis are a viable option for the restoration of edentulous ridges. Several procedures now allow for the fabrication of immediate-loading provisional and definitive prostheses. However, this complex treatment is not accessible to all patients with budget restrictions. By using a unique master model with a single titanium framework prosthesis can simplify and shorten the treatment, as well as reduce costs. After surgical placement of implant fixtures, an interim prosthesis was fabricated using a laser-welded definitive titanium framework. The prosthesis was fitted intraorally following the immediate loading protocols. The master cast model used to fabricate interim prosthesis was conserved and subsequently used in modifying the final prosthesis. After the healing process and complete soft tissue stability, an impression was made to register the clearance between the gingiva and resin. The light silicone material was directly injected under the prosthesis screwed in the mouth. In the master cast model, the stone was eliminated between the implants and a new plaster was poured to modify the crest profile with the posthealing new shape. With this modified model, it is possible to rehabilitate the denture to the new gingival anatomy in 3 to 4 hours and, if necessary, the tooth rearrangement. This “one shot” concept combines the single definitive titanium welded framework and limited laboratory work with a unique master model thereby decreasing the cost and the time of treatment.

Planejamento virtual utilizando software de livre acesso

The orthodontic setup is a tool used for tridimensional simulation for visual treatment planning. Its analysis allows to plan the mechanics to be used during the orthodontic treatment. For this purpose, it is necessary to duplicate the cast model, to cut the teeth and replace them in their respective cast bases. However, this process demands laboratory time and physical space for cast models storage. The traditional setup with cast models has been substituted by the 3D virtual version once it does not demand physical space for storage. Despite the learning curve, the 3D virtual computerized process has a reduced time when compared to the setup with cast models. But the software high cost is still the main point of disadvantage for its use. Thus, the aim of this study is to describe a step-by-step of 3D virtual orthodontic setup process, by using an open-source software.

Trueness of 12 intraoral scanners in the full-arch implant impression: a comparative in vitro study

Background The literature has not yet validated the use of intraoral scanners (IOSs) for full-arch (FA) implant impression. Hence, the aim of this in vitro study was to assess and compare the trueness of 12 different IOSs in FA implant impression. Methods A stone-cast model of a totally edentulous maxilla with 6 implant analogues and scanbodies (SBs) was scanned with a desktop scanner (Freedom UHD®) to capture a reference model (RM), and with 12 IOSs (ITERO ELEMENTS 5D®; PRIMESCAN® and OMNICAM®; CS 3700® and CS 3600®; TRIOS3®; i-500®; EMERALD S® and EMERALD®; VIRTUO VIVO® and DWIO®; RUNEYES QUICKSCAN®). Ten scans were taken using each IOS, and each was compared to the RM, to evaluate trueness. A mesh/mesh method and a nurbs/nurbs method were used to evaluate the overall trueness of the scans; linear and cross distances between the SBs were used to evaluate the local trueness of the scans. The analysis was performed using reverse engineering software (Studio®, Geomagics; Magics®, Materialise). A statistical evaluation was performed. Results With the mesh/mesh method, the best results were obtained by CS 3700® (mean error 30.4 μm) followed by ITERO ELEMENTS 5D® (31.4 μm), i-500® (32.2 μm), TRIOS 3® (36.4 μm), CS 3600® (36.5 μm), PRIMESCAN® (38.4 μm), VIRTUO VIVO® (43.8 μm), RUNEYES® (44.4 μm), EMERALD S® (52.9 μm), EMERALD® (76.1 μm), OMNICAM® (79.6 μm) and DWIO® (98.4 μm). With the nurbs/nurbs method, the best results were obtained by ITERO ELEMENTS 5D® (mean error 16.1 μm), followed by PRIMESCAN® (19.3 μm), TRIOS 3® (20.2 μm), i-500® (20.8 μm), CS 3700® (21.9 μm), CS 3600® (24.4 μm), VIRTUO VIVO® (32.0 μm), RUNEYES® (33.9 μm), EMERALD S® (36.8 μm), OMNICAM® (47.0 μm), EMERALD® (51.9 μm) and DWIO® (69.9 μm). Statistically significant differences were found between the IOSs. Linear and cross distances between the SBs (local trueness analysis) confirmed the data that emerged from the overall trueness evaluation. Conclusions Different levels of trueness were found among the IOSs evaluated in this study. Further studies are needed to confirm these results.

Upper Lip Horizontal Line: Characteristics of a Dynamic Facial Line

Background: Upper lip appearance received major attention with the introduction of diverse treatment modalities, including lip augmentation, rhinoplasty surgery, and dental treatment designed to support the upper lip. Our objectives were to define the prevalence and characteristics of the upper lip horizontal line (ULHL), which is a dynamic line appearing during a smile, in relation to gender, malocclusions, aging, and facial morphology. Methods: First, the prevalence and gender distribution of ULHL was examined from standardized en-face imaging at full smile of 643 randomly selected patients. Second, cephalometric and dental cast model analyses were made for 97 consecutive patients divided into three age groups. Results: ULHL appears in 13.8% of the population examined, and prevailed significantly more in females (78%). The prevalence of ULHL was not related to age nor to malocclusion. Patients presenting ULHL showed shorter upper lip and deeper lip sulcus. The skeletal pattern showed longer mid-face, shorter lower facial height and greater prevalence of a gummy smile. Conclusions: Female patients with short upper lip, concavity of the upper lip, and gummy smile are more likely to exhibit ULHL. The ULHL is not age-related and can be identified in children and young adults. Therefore, it should be considered when selecting diverse treatment modalities involving the upper lip.

The First Clinical Use of Augmented Reality to Treat Salivary Stones

In this study, we report our first experience of applying the concretion visualization method using augmented reality technology. A clinical case of a new surgical intervention on the parotid salivary gland with the localization of salivary stone in its parenchyma is considered. During additional diagnostics, it was found that the size of the concretion exceeds 5 mm which did not allow us to use the endoscopic technologies. That was the reason for the choice of surgical intervention external access using salivary stone visualization with the help of augmented reality. The preoperative procedures included making the upper jaw cast model, fitting the model and individual mouthguard with an X-ray contrast marker and marker slot. In addition to this, computed tomography of the head and neck using a mouthguard was made. During surgery under general anesthesia with nasal intubation, the mouthguard together with the marker is installed in the patient’s mouth and the surgeon puts on the glasses to visualize the stone image in place of its localization. This method enables to visualize the salivary stone on all surgery stages no matter what type of approach is used or performing hydropreparation. That is why using the augmented reality appears promising and is to be studied further.