Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:16 Issue: 4, Autumn 2022

Background:

 Bone reconstruction with appropriate quality and quantity for dental implant replacement in the alveolar ridge is a challenge in dentistry. As dental pulp stem cells (DPSCs) could be a new perspective in bone regeneration in the future, this study investigated the bone regeneration process by DPSCs.

Methods: 

Electronic searches for articles in the PubMed, EMBASE, and Scopus databases were completed until 21 April 2022. The most important inclusion criteria for selecting in vivo studies reporting quantitative data based on new bone volume and new bone area. The quality assessment was performed based on Cochrane’s checklist.

Results: 

After the title, abstract, and full-text screening of 762 studies, 23 studies were included. A meta-analysis of 70 studies that reported bone regeneration based on new bone area showed a statistically significant favorable influence on bone tissue regeneration compared to the control groups (P<0.00001, standardized mean difference [SMD]=2.40, 95% CI: 1.55‒3.26; I 2=83%). Also, the meta-analysis of 14 studies that reported new bone regeneration based on bone volume showed a statistically significant favorable influence on bone tissue regeneration compared to the control groups (P=0.0003, SMD=1.85, 95% CI: 0.85‒2.85; I2=84%).

Conclusion: 

This systematic review indicated that DPSCs in tissue regeneration therapy significantly affected bone tissue complex regeneration. However, more and less diverse preclinical studies will enable more powerful meta-analyses in the future.

In the recent day, there has been an exponential growth in the usage of clear aligners for orthodontic treatment. As with any removable appliance, the compliance of patients to remove it during ingestion of food is, at times, poor. Thus, the stability of the clear aligner to be “clear” becomes questionable. This in-vitro study examined how the clear aligners changed colour on exposure to various indigenous food products used in everyday life.

Aligners from 5 different companies (K Line, Clearbite Aligners, The Aligner Company, iAligners and MaxDent CA Digital) were exposed for 12 hours and 24 hours to various indigenous substances (tea, green tea, coffee, turmeric, saffron and Kashmiri red chili powder) and a control solution (distilled water) in-vitro. The color change was assessed with the help of VITA Easyshade compact colorimeter based on Commission Internationale de I’Eclairage L*a*b* color system. Values were then modified to NBS units for clinical relevance.

The hue of the transparent aligners was noticed to change in a statistically meaningful way when exposed to turmeric, saffron, Kashmiri red chili powder and coffee in decreasing order and mild color change in tea and green tea at both 12 hours and 24 hours intervals.

Aligners are prone to color change when exposed to indigenous foods that contain staining properties.

The purpose of this study was to assess the push-out bond strength of calcium-silicate and silicone based root canal sealers in bulk and with main cone.

Roots (n=48) randomly divided into 4 groups (n=12) according to the obturation protocol; (1) iRoot SP in bulk; (2) iRoot SP with gutta-percha; (3) GuttaFlow Bioseal in bulk; (4) GuttaFlow Bioseal with gutta-percha. Six horizontal sections were obtained from each root (n=72). Effect of sealers on bond strength was statistically significant (P<0.05).

Highest mean value was obtained in iRoot-Bulk group and lowest in GuttaFlow Bioseal-GP group. Both iRoot SP groups had significantly higher bond strength values than both GuttaFlow Bioseal groups (P<0.05). There was no significant difference between iRoot-GP and iRoot-Bulk groups (P=0.603) also GuttaFlow Bioseal-GP and GuttaFlow Bioseal-Bulk groups (P=0.684).

Based on findings, using calcium silicate-based sealer in bulk can be also suitable in clinical practice.

This study aimed to investigate whether the alignment of the teeth while smiling alters the visual perception by laypeople using eye tracking.

Facial images (two males and two females) were digitally edited to show a smile pattern with aligned teeth and one with crowded teeth. Sixty laypeople were selected to observe the images. The number of fixations, fixation duration, and time until the first fixation were recorded using an eye-tracking system. The results were qualitatively calculated with dot maps. Numerical data were analyzed using an independent Student’s t test.

There were no significant differences in fixation duration and the number of fixations in the crowded smile, mainly that of the male. The fixation times for the teeth were significantly different when the participants viewed the male subjects with a crowded smile (P<0.05). Dot maps showed greater attention to the smile with crowded teeth in both genders.

The crowded maxillary incisor smile attracted more visual attention to males from laypeople.

Using antibacterial agents to remove the foul odor of the implant cavity and prevent peri-implantitis can affect the detorque values and lead to the loosening of the abutment screw. This study investigated the effects of tetracycline and chlorhexidine gel on detorque values.

This in vitro study was carried out on three groups of five implants. Group G1 was the control group, and no material was applied to the implant cavity. In group G2, the implant cavity was first filled with artificial saliva and then with chlorhexidine gel. In group G3, the implant cavity was first filled with artificial saliva and then with tetracycline. The abutments were tightened with 25 N/cm2 and then loosened. Finally, the detorque values were calculated.

The highest detorque values were recorded in group G1. Group G3 showed the lowest detorque values. ANOVA showed significant differences in mean detorque values (P<0.05) between the three groups.

According to this study, applying antibacterial agents decreased the detorque values and increased the risk of screw loosening. The reduction of detorque values was more pronounced with the oil-based antibacterial agent (tetracycline).

The present study assessed the quality of images and the presence of marginal gaps on cone-beam computed tomography (CBCT) images of teeth restored with all-ceramic and metal-ceramic crowns and compared the gap sizes observed on CBCT images with those obtained on micro-CT images.

Thirty teeth restored with metal-ceramic and all-ceramic crowns, properly adapted and with gaps of 0.30 and 0.50 mm, were submitted to micro-CT and CBCT scans. Linear measurements corresponding to the marginal gap (MG) and the absolute marginal discrepancy (AMD) were obtained. The objective assessment of the quality of CBCT images was performed using the contrast-to-noise ratio (CNR), and the subjective assessment was defined by the diagnoses made by five examiners regarding the presence or absence of gaps.

The measurements were always higher for CBCT, with a significant difference regarding AMD. No significant difference in image quality was observed using CNR between the crowns tested. Low accuracy and sensitivity values could be observed for both crowns.

Marginal mismatch measures were overestimated in CBCT images. No difference in image quality was observed between the crowns. The correct diagnosis of gaps was considered low, irrespective of crown type and gap size.

Aesthetic expectations have increased the use of aesthetic materials in dentistry. Lithium disilicates are frequently used materials for these expectations. Bleaching is another method used to provide aesthetics. Bleaching processes on restorative materials are not fully known. This study investigated the effect of at-home and in-office bleaching methods on the color change, surface roughness, and topography of lithium disilicate glass-ceramic materials produced with two different techniques and subjected to different polishing procedures.

A total of 144 disc-shaped pressed and computer-aided design (CAD) lithium disilicate glass-ceramic specimens were randomly divided into four groups. Glazing and three different chair-side polishing procedures were performed. The specimens in each group were randomly divided into two groups and subjected to at-home and in-office bleaching processes (n=9). The home bleaching process was repeated with 16% carbamide peroxide agent for six hours for seven days, while the in-office bleaching process was applied with 40% hydrogen peroxide agent for two sessions of 20 minutes. After the bleaching processes, the final color and surface roughness experiments of the specimens were carried out, and the results were recorded. ANOVA and Tukey multiple comparison tests were used FOR the statistical analysis of the data (α=0.05).

The material*polish*bleaching, polish*bleaching, material*bleaching, and material*polishing interactions were not statistically significant regarding color and roughness changes of both specimens (P>0.05).

Both bleaching processes can be safely applied to lithium disilicate glass-ceramic materials.

Implant-supported cantilever prostheses enable a more straightforward rehabilitation and may be a therapeutic option to reduce treatment morbidity, costs, and time. This study evaluated the clinical outcomes of fixed implant-supported partial dentures made of monolithic zirconia with a cantilever design to replace missing posterior teeth.

Fifteen partially edentulous patients received 34 implants and were provided with 16 zirconia fixed partial prostheses (FPPs) with one cantilever extension replacing mandibular or maxillary missing posterior and lateral teeth. Patients were re-examined for up to 4 years. Patient ages ranged from 41 to 65 years, with a mean age of 53±12 years; 47% were female, and 53% were male. The patients were observed for a mean period of 42±6 months with a minimum of 3 years and a maximum of 4 years.

Peri-implantitis was observed in two cases. No chipping or fracture of any FPP was detected. Loosening of the abutment screw was a technical complication in one case. The rehabilitation survival rate was 100%. Implant-supported zirconia FPP with one mesial cantilever extension provides an aesthetic, functional treatment alternative to replace missing molars, premolars, and canines. These excellent clinical outcomes occurred over a mean observation time of 42±6 months.

Using monolithic zirconia milled with CAD-CAM technology might be an alternative to the metal-ceramic restoration in implant-supported FPP with one cantilever.

The present study evaluated the clinical and radiographic outcomes of Biodentine pulpotomy for 24 months in symptomatic vital mature permanent teeth with caries exposure.

Seventy-three patients with a chief complaint of spontaneous pain in permanent teeth were screened. Finally, 47 mature permanent teeth underwent a Biodentine pulpotomy procedure. Clinical evaluation of 47 teeth was carried out at 1, 3, 6, 9, 12, and 24 months and radiographic evaluations were made at 6, 12, and 24 months. The success of Biodentine pulpotomy was evaluated using Pearson’s chi-square test. The significance level was determined at P<0.05.

At 24 months, the clinical and radiographic success rate was 97.78%, with only one clinical failure at 9 months.

The clinical and radiographic success of Biodentine pulpotomy was high (97.78%). Thus, Biodentine pulpotomy can be an alternative to root canal treatment (RCT) in symptomatic vital mature permanent teeth.

Dentigerous cysts are common odontogenic cysts of the jaw but are rarely associated with supernumerary teeth. Few cases of large dentigerous cysts associated with anterior maxillary supernumerary teeth have been reported. The English literature has documented only four cases of dentigerous cysts>40 mm in diameter associated with supernumerary teeth. A 47-year-old man was referred to our hospital, complaining of minor pain in the maxillary gingiva. Computed tomography revealed a well-defined oval unilocular radiolucent lesion (50×45×35 mm) in the right maxilla, including two impacted supernumerary teeth. A dentigerous cyst associated with impacted anterior maxillary supernumerary teeth was diagnosed. The two impacted teeth were surgically removed, and the cyst was enucleated using the Caldwell-Luc approach. Histopathology confirmed the diagnosis of a large dentigerous cyst associated with impacted anterior maxillary supernumerary teeth. The postoperative course has been uneventful for two years. We also reviewed the relevant English literature.

In the article entitled “Evaluation of Pharyngeal Airway Dimensions and Hyoid Bone Position in Children After Adenoidectomy or Adenotonsillectomy: A Cephalometric Study” which appeared in J Dent Res Dent Clin Dent Prospect 2022;16(2): 81-86. doi: 10.34172/joddd.2022.013, the name of the first author was misspelled. The correct name of the first author is Muhammed Hilmi Buyukcavus. The original version of the article has been updated to reflect these corrections.