scholarly journals Validation of the Accuracy of Postoperative Analysis Methods for Locating the Actual Position of Implants: An In Vitro Study

2020 ◽  
Vol 10 (20) ◽  
pp. 7266
Author(s):  
Se-Mok Oh ◽  
Du-Hyeong Lee
Keyword(s):  
In Vitro Study ◽  
Cone Beam ◽  
Measurement Variability ◽  
Implant Position ◽  
Actual Position ◽  
Mesh Model ◽  
Guide System ◽  
Automatic Matching ◽  
Post Hoc

Assessment of the accuracy of an implant guide system is essential, yet the reliability of postoperative methods for locating the implant position has still not been clarified. This study therefore sought to evaluate the accuracy of postoperative methods for locating the actual position of implants in terms of their linear and angular deviations. The implant position in a dentiform model was located using the following three methods: manual matching on a cone-beam computed tomography (CBCT) image (MC group), manual matching on a mesh model of CBCT (MM group), and automatic matching on a scan abutment of a scan image (AS group). Thirty clinicians adopted each method, and the estimated position of the implant in each group was compared three-dimensionally with the reference implant position using image analysis software in terms of the linear, vertical, and angular deviations. One-way analysis of variance (ANOVA) and Tukey’s post-hoc test were used for statistical analyses (α = 0.05). In general, the deviations were the largest in the MC group, followed by the MM group and the AS group. The ANOVA results suggested that all deviations values were markedly smaller in the AS group than in the MC group (p < 0.001). The interoperator measurement variability of all deviations was relatively smaller in the AS group than in the other two groups. The automatic matching method using scan abutments was more accurate than the manual matching methods using CBCT and mesh images in assessing the deviations that existed between the planned and actual positions of the implant. The use of scan abutments is recommended for the postoperative assessment of an implant’s placement location.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

scholarly journals Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt
Keyword(s):  
Gastroesophageal Reflux ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Wear ◽  
Control Group ◽  
Erosive Tooth Wear ◽  
Custom Made ◽  
Post Hoc ◽  
Bovine Enamel

Abstract Background This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. Methods Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. Results The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). Conclusions After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.

scholarly journals Accuracy of Guided Implant Surgery in the Edentulous Jaw Using Desktop 3D-Printed Mucosal Supported Guides

2021 ◽  
Vol 10 (3) ◽  
pp. 391
Author(s):  
Rani D’haese ◽  
Tom Vrombaut ◽  
Geert Hommez ◽  
Hugo De Bruyn ◽  
Stefan Vandeweghe
Keyword(s):  
In Vitro Study ◽  
Angular Deviation ◽  
Implant Surgery ◽  
Implant Position ◽  
Surgical Guides ◽  
Negative Effect ◽  
Bone Level ◽  
3D Printed ◽  
Implant Alignment

Purpose: The aim of this in vitro study is to evaluate the accuracy of implant position using mucosal supported surgical guides, produced by a desktop 3D printer. Methods: Ninety implants (Bone Level Roxolid, 4.1 mm × 10 mm, Straumann, Villerat, Switzerland) were placed in fifteen mandibular casts (Bonemodels, Castellón de la Plana, Spain). A mucosa-supported guide was designed and printed for each of the fifteen casts. After placement of the implants, the location was assessed by scanning the cast and scan bodies with an intra-oral scanner (Primescan®, Dentsply Sirona, York, PA, USA). Two comparisons were performed: one with the mucosa as a reference, and one where only the implants were aligned. Angular, coronal and apical deviations were measured. Results: The mean implant angular deviation for tissue and implant alignment were 3.25° (SD 1.69°) and 2.39° (SD 1.42°) respectively, the coronal deviation 0.82 mm (SD 0.43 mm) and 0.45 mm (SD 0.31 mm) and the apical deviation 0.99 mm (SD 0.45 mm) and 0.71 mm (SD 0.43 mm). All three variables were significantly different between the tissue and implant alignment (p < 0.001). Conclusion: Based on the results of this study, we conclude that guided implant surgery using desktop 3D printed mucosa-supported guides has a clinically acceptable level of accuracy. The resilience of the mucosa has a negative effect on the guide stability and increases the deviation in implant position.

scholarly journals External cooling efficiently controls intraosseous temperature rise caused by drilling in a drilling guide system: an in vitro study

2015 ◽  
Vol 53 (10) ◽  
pp. 963-967 ◽  
Author(s):  
Kristof Boa ◽  
Endre Varga ◽  
Gabor Pinter ◽  
Akos Csonka ◽  
Istvan Gargyan ◽  
...  
Keyword(s):  
Temperature Rise ◽  
In Vitro Study ◽  
Vitro Study ◽  
External Cooling ◽  
Guide System

The Influence of Using Different Types of Scan Bodies on the Transfer Accuracy of Implant Position: An In Vitro Study

2021 ◽  
Vol 34 (2) ◽  
pp. 254-260
Author(s):  
Alexander Schmidt ◽  
Jan-Wilhelm Billig ◽  
Maximiliane Schlenz ◽  
Bernd Wöstmann
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Implant Position ◽  
Different Types ◽  
Transfer Accuracy

scholarly journals Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  
Keyword(s):  
Room Temperature ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Bottom Surface ◽  
Steel Mold ◽  
Polymerization Condition ◽  
Post Hoc

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

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