Three-Dimensional Measurements of the Palate and Dental Arch Perimeter as Predictors for Maxillary Palatal Canine Impaction-A Cone-Beam Computed Tomography Image Analysis.

(1) Background: Accurate diagnosis and treatment plans in orthodontics were facilitated by novel technologies. The prediction of occlusal problems is of utmost importance for clinicians. This present study aimed to find any possible correlation between unilateral and bilateral palatally impacted maxillary canine, palatal dimensions, and maxillary arch perimeter using digital measurements and determine the factors that could be used as predictors for maxillary palatal canine impaction. (2) Method: A cross-sectional study was conducted on cone-beam computed tomography images of orthodontic patients aged 15 to 25. Palatal dimensions and maxillary arch perimeter were digitally measured using Materialize Interactive Medical Image Control System. (3) Results: A significant difference was found between the case and the study groups regarding palatal depth, length, and arch perimeter, except for the palatal width. A weak correlation was reported in palatal depth and length with canine impaction, whereas the correlation was moderate concerning the arch perimeter. They can be used as predictors for palatal canine impaction. (4) Conclusion: Palatal dimensions and dental arch perimeter affect maxillary palatal canine impaction. Deficient arch perimeter, palatal depth, and length could be helpful in the prediction of maxillary palatal canine impaction.

Visual inspection of root patterns and radiographic estimation of its canal configurations by confirmation using sectioning method. An ex vivo study on maxillary first premolar teeth.

BACKGROUND: A thorough understanding of the original root and canal anatomy is a critical technical prerequisite for performing cleaning and shaping treatments. Therefore, this research aimed to characterize maxillary first premolar teeth' root morphology and canal architecture. METHODS: One hundred forty-two extracted human adult maxillary first premolar teeth have been retrieved. The extracted teeth were thoroughly cleaned and irrigated to eliminate any remaining debris or blood. They were then preserved in formalin solution until they were eligible for screening. To begin, a visual examination was employed to ascertain the number of roots and their geometry in each sample. Then, utilizing digital radiography in two plains, mesiodistal and distomesial, to further determine those parameters. Finally, a sectioning technique had been used to have the samples cut mesiodistally into slices to validate the internal root canal architecture and identify the number of root canals and their varieties in accordance with Vertucci's categorization system. The canal layout, the pulp chamber, and the root canals were all highlighted (marked) using a fine tip marker in a permanent orange hue to make the canal features more accessible and accurate to visualize. All of the processes were conducted by two highly qualified dentists. The sample size was estimated statistically using the Sealed Envelope program, and the percentage of each configuration was derived in proportion to the overall sample size in order to establish the percentage of each type in each configuration. RESULTS: From the 142 teeth examined, 42 (29.57%) had one root, 97 (68.31%) had two roots, and only three premolars (2.12%) had three roots. Concerning canal configurations, 100 teeth (70.43%) had type (IV) canal configuration, followed by 37 teeth (26.05%) had types (V), three teeth (2.12%) had type (VIII), and one tooth (0.70%) for each of type (I) and type (II). CONCLUSIONS: The anatomical pattern of inspected maxillary first premolars are mainly two rooted and predominantly have a type (IV) canal morphology.

Scanning Electron Microscope Image Analysis of Bonding Surfaces following Removal of Composite Resin Restoration Using Er: YAG Laser: In Vitro Study.

It is impossible to remove tooth-colored restorations by mechanical means without unnecessary damage to the adjacent sound tooth structure. This study is aimed at investigating erbium-doped yttrium aluminum garnet (Er: YAG) laser (Hoya ConBio, VersaWave, CA, USA) in removing composite resin restorations and assessing the change in morphology of bonding surfaces using a scanning electron microscope (EDX, CAMSCANNER, 3200LV, UK). The investigators collected thirty extracted sound human premolar teeth for this investigation, and the conventional design class V cavity was prepared on the buccal surface of each specimen. The specimens were allocated randomly into three groups, according to the procedure used for the ablation of the composite restoration: group A (high-speed diamond fissure bur), group B, and group C (Er: YAG laser) using a different pulse repetition rate of 20 Hz (group B) and 25 Hz (group C). The AutoCAD software program (Autodesk, Inc., 2016) was used to calculate the surface area and the resulting dimensional change of the cavities after restoration removal. The cavities were filled with composite resin and randomly assigned into two groups conforming to the methods applied to eliminate the restoration; diamond turbine fissure bur and laser. In each group, two specimens were selected randomly for scanning electron microscope analysis of bonding surfaces. The least meantime for the composite resin removal was observed in the high-speed diamond bur, significantly less than both Er-YAG laser groups (p < 0.001). However, at a higher pulse repetition rate, time-consuming decreased. The results showed that laser is more conservative in removing composite resin restoration as the change was most remarkable in group A (0.800 mm), then group C (0.466 mm), and the slightest change is in group B (0.372 mm) (p = 0.014). The dentin surface of group A showed a smooth surface with no opened dentinal tubule and intact smear layer. In groups B and C, dentin surfaces were irregular, scaly, or flaky, and dentinal tubules were opened without a smear layer. Therefore, Er: YAG laser is effective for composite resin removal considering the parameters chosen in this study with fewer changes in cavity surface area and better microretentive features.

Impact of Bleaching before or after Veneer Preparation on Color Masking Ability of Laminate Veneers: An In Vitro Study.

PURPOSE: This study evaluates the effect of bleaching before or after veneer preparation and the depth of preparation on color masking ability of laminate veneers. Methods. Sixty extracted premolars were artificially stained to vita shade A4, verified by digital spectrophotometer (Vita Easy Shade V), and then divided into three groups: NB = nonbleached, BBP = bleaching before preparation, and BAP = bleaching after preparation. Based on the preparation depths, each group was further divided into two subgroups: S1 = 0.5 mm and S2 = 1.0 mm. BBP and BAP were subjected to one session of in-office bleaching using 35% hydrogen peroxide. IPS e-max CAD veneers of 0.5 and 1.0 mm thickness (corresponding to the preparation depths) of the same shade and translucency (HT A1) were cemented immediately to the bleached surfaces. Immediately after cementation, the color change ΔE between the baseline (after staining) and the resulted shades was measured using the Vita Easy Shade V digital spectrophotometer and CIELab color system. RESULTS: Bleached groups exhibited a significant ΔE value compared to the nonbleached group (p < 0.05). BAP showed the highest ΔE value. No significant difference was found between BBP and BAP. S2 revealed a significant ΔE value than S1 (p < 0.05). No significant difference was found between S1of BAP and S2 of NB, BBP, and BAP (p > 0.05). Regarding the color coordinates, the difference between the tested groups was highly significant in lightness (ΔL∗) (p < 0.001), while no significant differences were found in green/red value (Δa∗) and yellow/blue value (Δb∗) (p > 0.05). CONCLUSIONS: In cases of severe tooth discoloration, one session of in-office bleaching before or after veneer preparation and the preparation depth do not influence the color masking ability of laminate veneers.

Root canal curvature as a prognostic factor influencing the diagnostic accuracy of radiographic working length determination and postoperative canal axis modification: an in vitro comparative study.

BACKGROUND: Radiographic analysis of tooth morphology is mandatory for accurate calibration of the degree of canal curvature angle and radiographic working length to its real dimensions in case difficulty assessment protocols. This study aimed to determine the impact of the degree of root canal curvature angle on maintaining the real working length and the original canal axis of prepared root canals using a reciprocating rotary instrumentation technique. METHODS: Radiographic image analysis was performed on 60 extracted single-rooted human premolar teeth with a moderate canal curvature (10°-25°) and severe canal curvature (26°-70°). Working length and longitudinal canal axis were determined using cone-beam computed tomography (CBCT) and digital periapical radiography. The real canal length was determined by subtracting 0.5 mm from the actual canal length. Root canals were prepared using the WaveOne Gold reciprocating file (Dentsply Maillefer, Ballaigues, Switzerland). RESULTS: There was no significant relation of the degree of canal curvature angle to the accuracy of radiographic working length estimated on CBCT and digital periapical radiographic techniques (P > 0.05). Postinstrumentation changes in the original canal axis between moderate and severe canal curvature angles, assessed on CBCT and periapical digital radiographic images were statistically non-significant (P > 0.05). CONCLUSIONS: A standardized digital periapical radiographic method performed similarly to the CBCT technique near to its true working length. No significant interaction exists between the diagnostic working length estimation, postoperative root canal axis modification, and the degree of canal curvature angle, using reciprocating rotary instrumentation technique.

The frequency of the second mesiobuccal canal in maxillary first molars among a sample of the Kurdistan Region-Iraq population - A retrospective cone-beam computed tomography evaluation.

BACKGROUND/PURPOSE: One of the most complexes in root and canal anatomy is the maxillary first permanent molar. This study aimed to analyze the frequency of mesiobuccal (MB2) canal and its apical portals of exit, in patients belonging to different gender-age groups and determine the possible relation with sex and age. MATERIALS AND METHODS: A CBCT scan images were accessed from a documented database of 343 patients (178 male, 165 female), who had an oral and maxillofacial examination. The age of the patients ranging from 12 to 63 years. The frequency of the MB2 canal and its portals of exit apically were observed. Age and gender correlation were calculated using the χ2 test. P < 0.05 was considered significant. RESULTS: A total of 634 maxillary first molars (335 male, 299 female) were included. The MB2 canal was found in 53.78% of the cases. A significantly higher incidence of the MB2 canal was detected in males than in females. No correlation in the presence and/or absence of the MB2 canal in terms of age. When MB2 canal present, a single apical foramen was observed in 66.28% of the cases, two apical foramina were present in 33.72% of the cases. CONCLUSION: MB2 canals may be present in approximately half of the cases, from which one third of the cases have their own apical portal of exit.

Estimation Accuracy of Root Canal Curvatures from Different Dental Diagnostic Imaging Techniques: An In Vitro Experimental Study.

In clinical endodontics, preoperative estimation of root canal curvature is crucial regarding the prevention of iatrogenic errors. Reproduction of the two-dimensional radiographic images causes certain proximal view curvatures not seen. Therefore, the present study is aimed at investigating the degree of root canal curvature identified in different radiographic views. A total of 60 human permanent single-rooted teeth with varying degrees of curvature were selected. The root canal curvature for each tooth was measured on cone-beam computed tomography (CBCT) images (clinical view), standard digital periapical view (0° angle), digital periapical horizontal parallax view (30° angle), and digital periapical proximal view (0° angle), by using the Schneider method. No statistically significant difference was found in the degree of curvatures estimated on CBCT images and standard digital periapical view (0° angle) in the same tooth. The results revealed a significant difference between the proximal view and the other three groups (p < 0.05). There was no significant difference in this respect between the horizontal parallax view (30° angle), clinical view (CBCT images), and standard digital periapical view (p > 0.05). Proximal view curvatures cannot be predicted or estimated only from examining a clinical view radiograph. A horizontal parallax view (30° angle) is highly recommended as specific guidelines on how to estimate root canal curvature in case difficulty assessment protocols.

Preoperative Estimation of Endodontic Working Length with Cone-Beam Computed Tomography and Standardized Paralleling Technique in comparison to Its Real Length.

An accurate estimation of the working canal length is essential for successful root canal treatment. This study is aimed at investigating the diagnostic accuracy of root canal length estimation on cone-beam computed tomography (CBCT) scans and digital paralleling radiographs (PAs), using the real canal length as a gold standard, and at evaluating the influence of canal curvature on this estimation. Sixty extracted human premolar teeth were selected for this study. Root canal length measurement was performed on CBCT scans (NewTom, Giano, Verona, Italy) and digital paralleling radiography (EzRay Air W; Vatech, Korea). The real working length was established by subtracting 0.5 mm from the actual canal length. No significant difference was found between CBCT and digital paralleling radiography. There was a tendency for underestimation of the root canal length measured on the CBCT images in 52 (86.7%) of the examined teeth and overestimation in 5 teeth (8.3%). All the digital radiographs slightly overestimated the real canal length. The analysis revealed a strong correlation between the estimation from moderate to severe curvature for digital radiography and CBCT images. Preoperative working length estimation can be made closest to its real clinical canal length on the standardized paralleling technique, using a long (16-inch) target-receptor distance.

Evaluation of antibacterial effects of 5-aminolevulinic acid in combination with light emitting diode (LED: 635nm) with different disinfection methods.

This study evaluates the in vitro antibacterial effects of 5-ALA (photoactive dye) in regard to different disinfection methods (2% Chlorhexidine gluconate, 1% Sodium Hypochlorite) on cariogenic bacteria (Streptococcus mutans and Streptococcus sobrinus). After inoculation of dentin specimens with S. mutans and S. sobrinus separately, the reduction in bacterial count was evaluated by the colony counting method. A total of sixty specimens were assigned to six groups (Ten per each group, with five in each group inoculated with S. mutans and the other five inoculated with S.sobrinus); group one: positive control where no treatment was performed, group two: 1% NaOCl was applied, group three: 2% CHX was used, group four: 5-ALA with LED light (635 nm) was applied, group five: 5-ALA was used without LED light activation, group six: LED light was used without dye application. There was a significant reduction in the number of S. mutans in the group treated with 5-ALA with LED light, followed by CHX and then NaOCl, whilst minimum bacterial reduction was detected in the groups that were treated with LED light alone and 5-ALA without LED. However, NaOCl exhibited a better effect regarding reduction of S. sobrinus, followed by 5-ALA and LED light and then CHX. All the disinfected groups showed a significant relation with the positive control non-treated group(p < 0.05).

Four years of clinical experience with the efficacy of Pulpotec® as a root canal dressing for the management and control of odontogenic pain: a prospective randomized clinical trial.

AIM: The purpose of this prospective clinical study was to discover clinically the influence of Pulpotec® (Produits Dentaires S.A., Switzerland) on the incidence of inter-appointment flare-up, with a view to advance the resolution of pain and/or swelling in patients presenting for emergency root canal treatment. METHOD: In a prospective randomized clinical trial, pulpotec paste was used as an intracanal medicament in multi-appointment root canal treatment in 860 teeth (510 symptomatic and 350 asymptomatic) belonging to 860 patients from February 2008 to March 2012. The follow-up visit was scheduled, and the incidence and severity of inter-appointment pain was recorded at different time periods (8, 24, and 48 h, 3 days, and 1 week after the treatment) on simple descriptive pain intensity scale. Patients who experienced intense pain and/or swelling (flare-up) after the first treatment visit were given an emergency appointment during which pulpotec was used as an intracanal dressing. RESULTS: The incidence of intense pain was 10 (1.16%) and 6 (0.69%) of the treatment cases at 24 and 48 h, respectively. Moderate pain was described only by 137 patients within the 24 h-3 days time interval after treatment. At 7 days, all patients experienced no pain or only weak pain levels. CONCLUSION: Pulpotec intracanal dressing is beneficial in rapid resolution of pain and/or swelling in emergency root canal treatment and in controlling postoperative pain in multi-appointment root canal treatment.