Tubule Density and Diameter in Coronal Dentin from Primary and Permanent Human Teeth

2013 ◽  
Vol 19 (6) ◽  
pp. 1445-1449 ◽  
Author(s):  
Tathiane L. Lenzi ◽  
Camila de Almeida B. Guglielmi ◽  
Victor E. Arana-Chavez ◽  
Daniela P. Raggio

AbstractThis study compared dentinal tubule density and diameter of human primary and permanent teeth at different depths of the coronal dentin. Crowns of eight primary second molars and eight permanent third molars were serially sectioned into three disks of ~0.5 mm thickness (superficial, middle, and deep layers), perpendicular to the long axis. Tubule density and diameter were evaluated in 2,000× and 3,000× magnifications by scanning electron microscopy. Data obtained were subjected to two-way repeated measures ANOVA and Tukey's post hoc test (α = 0.05). Tubule density was greater in primary teeth compared with permanent ones, regardless of depth (primary: 124,329 ± 43,594 mm2; permanent: 45,972 ± 21,098 mm2). In general, the tubule density increased as the dentin depth increased, except to the superficial and middle layers from permanent teeth. Tubule diameter was larger in the dentin layer close to the pulp chamber (superficial: 2.4 ± 0.07 μm; middle: 3.70 ± 0.06 μm; deep: 4.28 ± 0.04 μm). No difference was observed between primary (3.48 ± 0.81 μm) and permanent teeth (3.47 ± 0.73 μm). The tubule diameter increases as the dentin depth increases for primary and permanent teeth; however, the tubule density is higher in primary teeth.

2021 ◽  
Vol 34 (1) ◽  
pp. 27-34
Author(s):  
Carlos Vieira ◽  
Francyelle Pires ◽  
Wallisen Hattori ◽  
Cleudmar de Araújo ◽  
Marcelo Garcia-Junior ◽  
...  

The risk of fracture or strain in mini-screws is higher if diameter, length, type of alloy or insertion angle is selected inappropriately. The aims of this study were to test the structural resistance of two types of orthodontic mini-screws –one made of stainless steel and another of titanium– from an international brand and to evaluate the efficacy of two other titanium miniscrews of Brazilian origin, during an extra-alveolar anchorage procedure. The mini-screws analyzed were: Bomei stainless steel and Bomei titanium / Taiwan, Morelli titanium and Neodent titanium/ Brazil. Experiments were conducted on pig mandibles to simulate the process of extra-alveolar anchorage. Two insertion processes were used: Direct at 30º, and Indirect, starting at 60º and ending at 30º with gradual continuous movement. Strain was evaluated using Optical and Scanning Electron Microscopy. Data were evaluated using Kruskal-Wallis non-parametric statistical analysis and post hoc Tamhane test. Significant statistical differences in strain were observed among the mini-screws used in the extra-alveolar insertions, both for the direct and indirect procedures. In the indirect insertion tests, both stainless steel and titanium mini-screws suffered deformation, showing that angling can be an important factor in mini-screw failure rates. The change in angle during the insertion movement increased deformation rates independently of alloy type, increasing the risk of failure. These results could help orthodontists in choosing mini-screws for extra-alveolar anchorage, which can be performed with direct or indirect insertion. In vivo studies should be conducted to confirm the findings of this study.


Author(s):  
Ruiqi Yang ◽  
Jun Tian ◽  
Xiangya Huang ◽  
Shuxiang Lei ◽  
Yanling Cai ◽  
...  

Abstract Objectives This study aimed to evaluate dentinal tubule penetration and the retreatability of EndoSequence BC Sealer HiFlow (HiFlow), iRoot SP, and AH Plus when using the single-cone (SC) or continuous wave condensation (CWC) technique. Materials and methods Sixty-five single-rooted teeth were instrumented and randomly divided into 5 groups: group 1, AH Plus/CWC; group 2, iRoot SP/CWC; group 3, iRoot SP/SC; group 4, HiFlow/CWC; and group 5, HiFlow/SC. The ability to re-establish patency during endodontic retreatment was recorded, as was the time taken to reach the working length. Dentinal tubule penetration and remaining debris after retreatment were evaluated by confocal microscopy and scanning electron microscopy. Data were analyzed by Kruskal-Wallis test and Dunn’s multiple comparisons test (α = 0.05). Results The HiFlow/CWC and iRoot SP/CWC groups required more time to reach the working length than groups that underwent the SC technique regardless of the sealer used (P < .05). The HiFlow/CWC group showed a significantly higher percentage of sealer penetration area than that of the iRoot SP/SC at 4 mm from the apex (P < .05) and penetrated deeper into dentinal tubules than iRoot SP/SC at both 8-mm and 12-mm levels (P < .05). Moreover, the HiFlow/CWC and HiFlow/SC groups demonstrated less remaining sealer along the canal wall than AH Plus/CWC group at 4-mm level (P < .05). Conclusions HiFlow/CWC technique showed better performance in dentinal tubule penetration than that of iRoot SP/SC. Both HiFlow and iRoot SP combined with CWC technique groups required more retreatment time than the other groups. Furthermore, using HiFlow with either the CWC or SC technique left less remaining sealer at 4-mm level than using AH Plus with the CWC technique during retreatment. Clinical relevance With favorable performance in dentinal tubule penetration and retreatability in endodontic retreatment, the combined use of EndoSequence BC Sealer HiFlow with the recommended continuous wave condensation technique may be a worthwhile choice in root canal treatment.


Author(s):  
Janina Golob Deeb ◽  
Connor McCall ◽  
William Dahlke ◽  
Caroline Carrico ◽  
Kinga Grzech-Leśniak

(1) Background: Prefabricated zirconia crowns are used to restore teeth in children. The purpose of this study was to evaluate the removal of these crowns with the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser; (2) Methods: Twelve primary and 13 permanent teeth were prepared and prefabricated zirconia crowns were passively fitted and cemented with two resin modified glass-ionomer cements. Surface areas of prepared teeth and crowns were calculated. Crowns were removed using two laser settings: 4.5 Watts, 15 Hertz, 20 water/ 20 air, and 5 Watts, 15 Hertz, 50 water/50 air. The retrieval time and temperature changes were tested recorded. Data were analyzed using ANOVA with Tuckey&rsquo;s adjusted post hoc pairwise comparison t-test; (3) Results: The average time for crown removal was: 3 minutes, 47.7 seconds for permanent; and 2 minutes 5 seconds for primary teeth. The mean temperature changes were 2.48℃ (SD=1.43) for permanent; and 3.14℃ (SD=1.88) for primary teeth. The time to debond was significantly positively correlated with tooth inner surface area and volume, outer crown volume, and the cement volume; (4) Conclusions: Use of the Er,Cr:YSGG laser is an effective, safe and non-invasive method to remove prefabricated zirconia crowns cemented with RMGI cements from permanent and primary teeth.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5569
Author(s):  
Janina Golob Deeb ◽  
Connor McCall ◽  
Caroline K. Carrico ◽  
William O. Dahlke ◽  
Kinga Grzech-Leśniak

(1) Background: Prefabricated zirconia crowns are used to restore teeth in children. The purpose of this study was to evaluate the removal of these crowns with the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser; (2) Methods: A total of 12 primary and 12 permanent teeth were prepared and prefabricated zirconia crowns were passively fitted and cemented with two resin modified glass-ionomer (RMGI) cements. Surface areas of prepared teeth and crowns were calculated. Crowns were removed using two laser settings: 4.5 Watts, 15 Hertz, 20 water/20 air, and 5 Watts, 15 Hertz, 50 water/50 air. The retrieval time and temperature changes were tested recorded. Data were analyzed using ANOVA with Tukey’s adjusted post hoc pairwise comparison t-test; (3) Results: The average time for crown removal was: 3 min, 47.7 s for permanent; and 2 min 5 s for primary teeth. The mean temperature changes were 2.48 °C (SD = 1.43) for permanent; and 3.14 °C (SD = 1.88) for primary teeth. The time to debond was significantly positively correlated with tooth inner surface area and volume, outer crown volume, and the cement volume; (4) Conclusions: Use of the Er,Cr:YSGG laser is an effective, safe and non-invasive method to remove prefabricated zirconia crowns cemented with RMGI cements from permanent and primary teeth.


Author(s):  
F. S. Ayupova ◽  
S. N. Alekseenko ◽  
V. Ya. Zobenko ◽  
T. V. Gayvoronskaya

Relevance. To study the incidence of different types of resorption of multirooted primary teeth, to specify indications for deciduous molar extraction to prevent eruption abnormalities of permanent posterior teeth in mixed dentition.Materials and methods. Root resorption of 375 multirooted primary teeth (166 first primary molars and 209 second primary molars) was studied on panoramic X-rays of 60 children (30 girls and 30 boys) aged between 7 and 15. Illustrated classification by T.F. Vinogradova (1967) improved by authors was used to determine type and degree of root resorption of multi-rooted primary teeth. Received data were described with absolute values of number of cases and percentage. Chi-square was used to detect differences in sign incidence rate between groups, p<0.05 was considered statistically significant.Results. There were no statistically significant gender differences (p>0,05) in type and degree of root resorption of multirooted primary teeth. Type A resorption prevailed and constituted 53.3% of all primary molars. Disturbances in root resorption of multirooted primary teeth in mixed dentition were related to health condition of primary teeth. Transition of even resorption to unven was considered a risk factor of delayed eruption and aberrant position of permanent teeth, and indication for extraction of a primary molar in question. Conclusions. 1) Even root resorption (type A) was detected in 53.3% of primary molars in mixed dentition by orthopantomography. 2) Transition from even resorption of primary molar roots to uneven resorption was associated with eruption deviations and delayed premolar eruption. 3) Timely extraction of primary molars with uneven root resorption facilitated correct eruption of premolars and increased effectiveness of secondary prevention of malocclusion in children.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dulanji K. Kuruppu ◽  
Joshua Tobin ◽  
Yan Dong ◽  
Sheena K. Aurora ◽  
Laura Yunes-Medina ◽  
...  

Abstract Background Galcanezumab is a calcitonin gene-related peptide (CGRP) monoclonal antibody (mAb) indicated for the preventive treatment of migraine. While galcanezumab has demonstrated efficacy in patients who did not respond to prior preventive medications in general, its efficacy in patients who did not benefit from individual, commonly prescribed preventive treatments due to inadequate efficacy or safety/tolerability remains unknown. Methods CONQUER was a 3-month, randomized, double-blind, placebo-controlled, phase 3b study that enrolled patients with episodic or chronic migraine who had 2 to 4 migraine preventive medication category failures in the past 10 years. Patients were randomly assigned 1:1 to receive placebo (N = 230) or galcanezumab 120 mg/month (240 mg loading dose; N = 232). Post hoc analyses were conducted to determine the efficacy of galcanezumab in patients who had not benefited from six of the most commonly prescribed migraine preventive medications. The mean change from baseline in monthly migraine headache days and ≥ 50 % response rates were assessed over months 1–3. Improvement in Migraine-Specific Questionnaire Role Function-Restrictive (MSQ-RFR) scores were assessed at month 3. The endpoints were estimated via mixed model with repeated measures. Results The most common treatment failures due to inadequate efficacy or safety/tolerability, which at least 20 % of patients reported trying without benefit, included topiramate, amitriptyline, propranolol, valproate or divalproex, onabotulinum toxin A, and metoprolol. Patients who had not previously benefited from these treatments had a greater mean reduction in monthly migraine headache days across months 1–3 in the galcanezumab group compared to placebo (all p < 0.01). More patients treated with galcanezumab experienced a ≥ 50 % reduction from baseline in monthly migraine headache days across months 1–3 compared to placebo (all p < 0.05). Galcanezumab-treated patients had a greater improvement in mean MSQ-RFR scores at month 3 compared to placebo (all p < 0.01). Conclusions In this population, galcanezumab was effective in reducing monthly migraine headache days, improving response rates, and enhancing quality of life in patients who had not previously benefited from topiramate, amitriptyline, propranolol, valproate or divalproex, onabotulinum toxin A, and/or metoprolol due to inadequate efficacy or safety/tolerability. Trial registration ClinicalTrials.gov NCT03559257 (CONQUER).


2021 ◽  
Vol 10 (13) ◽  
pp. 2760
Author(s):  
María León-López ◽  
Daniel Cabanillas-Balsera ◽  
Victoria Areal-Quecuty ◽  
Jenifer Martín-González ◽  
María C. Jiménez-Sánchez ◽  
...  

Aim. To conduct a systematic review and meta-analysis according to the following PICO question: in extracted human permanent teeth, does preflaring, compared with unflared canals, influence the accuracy of WL determination with EAL? Material and Methods. A systematic review was conducted according to the PRISMA checklist, using the following databases: PubMed, Science Direct, Scopus, and Web of Science. Studies related to WL determination using EAL both in preflared and unflared root canals of extracted human teeth were included. The outcome of interest was the accuracy of the electronic WL determination. A quality assessment of the included studies was performed, determining the risk of bias. The meta-analyses were calculated with the 5.4 RevMan software using the inverse variance method with random effects. PROSPERO registration: CRD42021243412. Results. Ten experimental studies fulfilled the inclusion criteria, and most of them found that preflaring increases the accuracy of the EALs in WL determination. The calculated OR was 1.98 (95% CI = 1.65–2.37; p < 0.00001; I2 = 10%), indicating that the determination of WL by EALs is almost twice as accurate in preflared canals. The accuracy of Root ZX in WL determination increases more than three times (OR = 3.25; p < 0.00001). Preflaring with Protaper files significantly increases the accuracy of EALs (OR = 1.76; p < 0.00001). The total risk of bias of the included studies was low. No obvious publication bias was observed. Conclusions. The results indicate a significant increase in the accuracy of WL determination with EAL after preflaring, doubling the percentage of exact measurements. Preflaring should be recommended as an important step during mechanical enlargement of the root canal, not only because it improves the access of the files to the canal, but also because it allows one to obtain more accurate electronic determinations of WL.


2007 ◽  
Vol 77 (4) ◽  
pp. 735-741 ◽  
Author(s):  
Richard Scott Conley ◽  
Scott B. Boyd ◽  
Harry L. Legan ◽  
Christopher C. Jernigan ◽  
Craig Starling ◽  
...  

Abstract An impacted or missing permanent tooth can add significant complications to an otherwise straightforward case. When multiple impacted teeth are present, the case complexity increases further. Developing a treatment sequence, determining appropriate anchorage, and planning and executing sound biomechanics can be a challenge. The following case report illustrates a patient reportedly diagnosed with mild scleroderma as an adolescent. He presented for orthodontic treatment as an adult with multiple retained primary teeth and multiple impacted teeth. Diagnosis, treatment planning, and various methods of managing guided eruption of impacted teeth will be discussed. Following orthodontic treatment that required extraction of multiple primary and permanent teeth as well as exposure and ligation of multiple permanent teeth by an oral surgeon, the patient finished with a significantly improved functional and esthetic result.


2013 ◽  
Vol 38 (5) ◽  
pp. E154-E165 ◽  
Author(s):  
E Mobarak ◽  
R Seyam

SUMMARY Objective The purpose of the study was to evaluate the nanoleakage and bond strength of different self adhesive systems cured with a modified-layering technique (MLT) to dentin of weakened roots. Methods Twenty-one maxillary incisors were decoronated and then root canals were instrumented and obturated with the cold lateral compaction technique. Weakened roots were simulated by flaring root canals until only 1 mm dentin thickness remained. Teeth were distributed into three groups. The canals were backfilled with Vertise Flow (VF group), a self-adhering system, following a modified-layering technique using two light-transmitting posts, sizes 6 and 3. DT Light Post size 2 was cemented using the same material. Remaining roots were prepared and cured in the same way as the VF group. However, in the TS/MF group, Clearfil Tri-S Bond (TS) adhesive and Clearfil Majesty Flow (MF) composite were used, while in the ED/PF group, ED primer II (ED)/Panavia F2.0 (PF) were used. After one week of storage, each root was sectioned to obtain six slices (two slices from each root third: coronal, middle and apical) of 0.9 ± 0.1 mm thickness. Interfacial nanoleakage expression was analyzed using a field emission scanning electron microscope (FEG-SEM), and the micro push-out bond strength (μPOBS) was measured at different root regions. Modes of failure were also determined using SEM. Data were statistically analyzed using two-way analysis of variance with repeated measures and Tukey post hoc test (p≤0.05). Results With MLT, all adhesive systems showed nanoleakage. For μPOBS, there was a statistically significant effect for adhesive systems (p&lt;0.001) but not for root region (p&lt;0.64) or for their interaction (p=0.99). Tukey post hoc test revealed that the bond strength of the VF group was significantly higher than the TS/MF and ED/PF groups for all root regions. Conclusion All of the tested self-adhesive systems cured using MLT had slight nanoleakage and were not sensitive to root regional differences. Self-adhering systems had higher bond strength than self-etch adhesives.


2005 ◽  
Vol 29 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Enrique Bimstein ◽  
Michael McIlwain ◽  
Joseph Katz ◽  
Greg Jerrell ◽  
Robert Primosch

The present case, of a child with an idiopathic immune deficiency and aggressive periodontitis in the primary dentition, serves as an example for the treatment considerations in these cases. Extraction of all the primary teeth proved to be the most adequate treatment. It allowed the child to eat properly and prevented unwanted infections that could endanger the life of the child. The newly erupted permanent teeth have been subjected to careful oral hygiene, clorhexidine topical applications, and have mild gingival inflammation and no attachment loss.


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