AIM: To evaluate the fracture resistance and failure pattern of three different cavity designs restored with monolithic zirconia.
MATERIALS AND METHODS: Human maxillary premolars atraumatically extracted for orthodontic reasons were chosen. A total of 40 teeth were selected and divided into four groups (n=10). Group I-Sound teeth (control with no preparation). Group II-MOD Inlay, Group III-Partial Onlay, Group IV-Complete Onlay. Restorations were fabricated with monolithic partially sintered zirconia CAD (SAGEMAX- NexxZr). All the 30 samples were cemented using Multilink Automix (Ivoclar) and subjected to fracture resistance testing using Universal Testing Machine (UTM) (Instron) with a steel ball of 3.5 mm diameter at crosshead speed of 0.5 mm/minute. Stereomicroscope was used to evaluate the modes of failure of the fractured specimen. Fracture resistance was tested using parametric one way ANOVA test, unpaired t-test and Tukey test. Fracture patterns were assessed using non-parametric Chi-square test.
RESULTS: Group IV (Complete Onlay) presented highest fracture resistance and showed statistical significant difference. Group II (MOD Inlay) and Group III (Partial Onlay) showed significantly lower values than the Group I (Sound teeth). However, Groups I, II and III presented no significant difference from each other. Coming to the modes of failure, Group II (MOD Inlay) and Group III (Partial Onlay) presented mixed type of failures; Group IV (Complete Onlay) demonstrated 70% Type I failures.
CONCLUSION: Of the three cavity designs evaluated, Complete Onlay had shown a significant increase in the fracture resistance than the Sound teeth.
Materials and Methods: This an in vitro study was done by preparing cavities on the buccocervical surface of 62 extracted premolar teeth which randomly assigned to two groups (n = 31) where Group 1 was restored with nanocomposite and Group 2 was cemented with porcelain cervical inlays. They were then subjected to thermocycling before immersion in 2% methylene blue dye for 24 h. Dye penetration depths were measured using Leica imaging system For statistical analysis, independent t-test was used to analyze the results (P < 0.05).
Results: Porcelain cervical inlay restorations demonstrated statistically lesser microleakage depth for the cervical margins (P = 0.018) when compared to CR. Deeper microleakage depth at the cervical compared to coronal margins of CR (P = 0.006) but no significant difference of both margins for porcelain cervical inlays (P = 0.600).
Conclusion: Porcelain cervical inlays show lesser microleakage than CR which could be alternative treatment option in restoring NCCL with better marginal seal and esthetics.
METHODS: Thirty adult participants (25 females and 5 males; mean age, 22.66 ± 3.27 years) with moderate upper labial segment crowding were randomly assigned into intervention and control groups using block randomization. All participants had first premolar extractions, bonded conventional fixed appliances, and 0.014-in, followed by 0.018-in nickel-titanium archwire placement for initial alignment. The intervention group received a 3-mm deep MOPs procedure under local anesthesia using a Propel device (Propel Ortho Singapore, Pte, Ltd, Winstedt Rd, Singapore) on the labial attached gingivae of maxillary incisors at monthly visits until complete alignment. Little's irregularity index was used to assess the overall changes and measure the change of tooth alignment of the 6 maxillary anterior teeth. Assessor blinding was employed.
RESULTS: There was no statistically significant difference in the median overall alignment duration between MOPs and control groups (139 days [95% confidence interval, 115.32-161.83] vs 143 days [95% confidence interval, 107.12-179.74]; hazard ratio, 0.829; P = 0.467). The MOPs procedure had no significant effect on the alignment duration (P = 0.657) and no overall significant difference in alignment improvement percentage among 2 groups on the basis of time (F = 2.53; P = 0.124). No harm was encountered.
CONCLUSIONS: The application of MOPs is no more effective in accelerating initial orthodontic alignment than conventional treatment.
TRIAL REGISTRATION: This trial was registered at the ISRCTN registry with the study ID ISRCTN15080404.
PROTOCOL: https://doi.org/10.1186/ISRCTN15080404.
FUNDING: This work was supported by the Postgraduate Trust Fund, Faculty of Dentistry, Universiti Teknologi MARA.
METHODOLOGY: STROBE guidelines were used to design a study using 60 periodontal ligament samples obtained from healthy lower premolars where extraction was indicated for orthodontic reasons. Prior to extraction 40 of these premolars were equally divided into four groups and root canals were prepared using different systems: Mtwo, Reciproc Blue, HyFlex EDM and Plex-V. Ten premolars were prepared with hand files and served as a positive control group. The remaining 10 premolars where extracted without treatment and served as a negative control group. All periodontal ligament samples were processed to measure the expression of SP, CGRP and their receptors by radioimmunoassay. Kruskal-Wallis and Duncan tests were performed to determine statistically significant differences between the groups for each variable.
RESULTS: Greater expression of all the peptides measured were found in the hand-file preparation group, followed by the Reciproc Blue, Mtwo, HyFlex EDM and Plex-V groups. The lower SP, CGRP and their receptors values were for the intact teeth control group. Kruskal-Wallis test showed statistically significant differences amongst groups (p
Material and method: Sixty freshly extracted human single-rooted mandibular premolar teeth were selected for the study. Teeth with fractured root, cracks, anddilacerations were rejected. All teeth were cleaned with ultrasonic scalers. Standard access opening was done and root canal treatment was performed with rotary files followed by obturation. After storing in saline for a week apical 3 mm of the root was resected at 900 angles to the long axis of the root. Retro cavity preparation was done with ultrasonic tips. The teeth were divided into four groups of 15 specimens each. Group I - Biodentin, GroupII-Bioaggregate, Group III - MTA Plus, and Group IV - MTA. After the restoration of retro cavities of all the teeth as per manufacture instructions, two coats of nail varnish were applied to leave apical 3 mm. All teeth were stored in 2% methylene blue for 72 h followed by emersion in 65% nitric acid for the next 72 h for Dye extraction. The obtained supernatant solution was then centrifuged and optical density or absorbance was measured with a UV spectrophotometer.
Result: Microleakage was found to be increasing in this order: Biodentin 0.01).
Conclusion: All materials exhibit some amount of microleakage. Biodentin shows the least microleakage among all the bioceramic material groups. Hence, Biodentin and bioaggregate are better material of choice for the retrograde filling to prevent microleakage.
MATERIALS AND METHODS: Thirty single-rooted mandibular premolars were standardized and prepared using ProTaper rotary files. The specimens were divided into a control group and two experimental groups receiving Diapex and Odontopaste medicament, either filled with iRoot SP or OrthoMTA, for 1 week. Each root was sectioned transversally, and the push-out bond strength and failure modes were evaluated. The data were analyzed using Kruskal Wallis and Mann-Whitney U post hoc test.
RESULTS: There was no significant difference between the bond strength of iRoot SP and OrthoMTA without medicaments and with the prior placement of Diapex (p value > 0.05). However, iRoot SP showed significantly higher bond strength with the prior placement of Odontopaste (p value < 0.05). Also, there was no association between bond strength of OrthoMTA with or without intracanal medicament (p value > 0.05) and between failure mode and root filling materials (p value > 0.05). The prominent failure mode for all groups was cohesive.
CONCLUSION: Prior application of Diapex has no effect on the bond strength of iRoot SP and OrthoMTA. However, Odontopaste improved the bond strength of iRoot SP.
CLINICAL SIGNIFICANCE: Dislodgment resistance of root canal filling from root dentin could be an indicator of the durability and prognosis of endodontic treated teeth.
METHODS: Five single maxillary premolar extraction sockets received PRF-CS grafts and five single maxillary premolar sockets received PRF-X grafts. Linear (horizontal and vertical) measurements were accomplished using Cone Beam Computed Tomography (CBCT) images and volumetric changes were assessed using MIMICS software. Soft tissue level changes were measured using Stonecast models. All measurements were recorded at baseline (before extraction) and at 5-months post-extraction.
RESULTS: Significant reduction in vertical and horizontal dimensions were observed in both groups except for distal bone height (DBH = 0.44 ± 0.45 mm, p = 0.09) and palatal bone height (PBH = 0.39 ± 0.34 mm, p = 0.06) in PRF-X group. PRF-CS group demonstrated mean horizontal shrinkage of 1.27 ± 0.82 mm (p = 0.02), when compared with PRF-X group (1.40 ± 0.85 mm, p = 0.02). Vertical resorption for mesial bone height (MBH = 0.56 ± 0.25 mm, p = 0.008), buccal bone height (BBH = 1.62 ± 0.91 mm, p = 0.01) and palatal bone height (PBH = 1.39 ± 0.87 mm, p = 0.02) in PRF-CS group was more than resorption in PRF-X group (MBH = 0.28 ± 0.14 mm, p = 0.01, BBH = 0.63 ± 0.39 mm, p = 0.02 and PBH = 0.39 ± 0.34 mm, p = 0.06). Volumetric bone resorption was significant within both groups (PRF-CS = 168.33 ± 63.68 mm3, p = 0.004; PRF-X = 102.88 ± 32.93 mm3, p = 0.002), though not significant (p = 0.08) when compared between groups. In PRF-X group, the distal soft tissue level (DSH = 1.00 ± 0.50 mm, p = 0.03) demonstrated almost 2 times more reduction when compared with PRF-CS group (DSH = 1.00 ± 1.00 mm, 0.08). The reduction of the buccal soft tissue level was pronounced in PRF-CS group (BSH = 2.00 ± 2.00 mm, p = 0.06) when compared with PRF-X group (BSH = 1.00 ± 1.50 mm, p = 0.05).
CONCLUSIONS: PRF-CS grafted sites showed no significant difference with PRF-X grafted sites in linear and volumetric dimensional changes and might show clinical benefits for socket augmentation. The study is officially registered with ClinicalTrials.gov Registration (NCT03851289).
MATERIALS AND METHODS: This study is conducted at Hospital Universiti Sains Malaysia. UCLP group comprised 48 patients with nonsyndromic UCLP who have had the lip and palate repaired, whereas the control group comprised 48 healthy noncleft cases. The lateral cephalometrics measurements were used to determine the vertical height, sagittal depth of the face, and cranial base length and angle. Maxillary arch dimensions were measured on the study cast including arch width, depth, and length.
RESULTS: Vertical facial height and sagittal depth measurements showed a significant decrease (P < 0.05) in the mean growth pattern in UCLP group. The anterior cranial base length (S-N) was shorter in UCLP children (P < 0.001), while Ba-N length had no significant difference (P = 0.639). Nasion-Sella Tursica-Basion angle was significantly higher in the UCLP group (P = 0.016). Dental arch width with reference to canine-to-canine and first premolar-to- first premolar distance was significantly larger in control (P = 0.001).
CONCLUSION: Mean vertical and sagittal facial dimensions in the UCLP children who do not undergo orthodontic treatment are significantly lesser in all directions of growth than healthy noncleft children. The maxillary dental arch had a normal depth but constricted in width and arch length.