Dental Root Surface Research Articles

Assessment of the root surface temperature during the use of intracanal agitation systems: In vitro study.

This study aimed to evaluate the temperature changes that the different methods of agitation of irrigants promote on the external dental root surface. Nine extracted human lower premolars were standardized by cone-beam computed tomography and used. The root canal was instrumented with a Reciproc 40.06 file. Temperature measurement was performed using K-type thermocouple sensors attached to the middle, cervical, and apical thirds of the teeth. The teeth had their roots immersed in distilled water at 37ºC, which were distributed into 3 experimental groups according to the mechanical agitation methods to be studied. US Group (n=3), Irrisonic Ultrasonic Tip activated through ultrasound; EC Group (n=3), Easyclean Tip coupled to a contra-angle low-speed handpiece; XP Group (n=3), XP-endo Finisher file coupled to an endodontic electrical motor. Temperature measurements were performed simultaneously with agitation and irrigation of intracanal irrigants. Statistical analysis was performed using SPSS software with a significance level of 5%. For multiple comparisons, the Tukey test was used. The association between mechanical agitation methods and root third was statistically significant. Regarding the temperatures recorded on the external surface of the roots, the ultrasonic tip was significantly higher than the XP-endo Finisher file and the Easyclean tip, which did not differ from each other. Regarding the ultrasonic tip, the external temperature in the middle third (39.46ºC) of the root was significantly lower than in the cervical (40.41ºC) and apical third (40.53ºC). None of the agitation methods of irrigants studied presented heating above 47ºC, and their use is safe for periodontal tissues.

Association of Dental Infections with Intracranial Atherosclerotic Stenosis

Introduction: Periodontal disease (PD) and dental caries are oral infections leading to tooth loss that are associated with atherosclerosis and cerebrovascular disease. We assessed the hypothesis that PD and caries are associated with asymptomatic intracranial atherosclerosis (ICAS) in the Atherosclerosis Risk in Communities (ARIC) study. Methods: Full-mouth clinical periodontal measurements (7 indices) collected at 6 sites per tooth from 6,155 subjects from the Dental Atherosclerosis Risk in Communities Study (DARIC) without prior stroke were used to differentiate seven PD stages (Periodontal Profile Class [PPC]-I to -VII) and dental caries on coronal dental surface (DS) and dental root surface (DRS). A stratified subset underwent 3D time-of-flight MR angiogram and 3D high isotropic-resolution black blood MRI. ICAS was graded according to the criteria established by the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial. We evaluated the relationship between PD stage and dental caries with asymptomatic ICAS, graded as no ICAS, <50% ICAS, and ≥50% ICAS. Results: Among dentate subjects who underwent vascular imaging, 801 (70%) had no ICAS, 232 (20%) had <50% ICAS, and 112 (10%) had ≥50% ICAS. Compared to participants without gum disease (PPC-I), participants with mild-moderate tooth loss (PPC-VI), severe tooth loss (PPC-VII), and severe PD (PPC-IV) had higher odds of having <50% ICAS. Participants with extensive gingivitis (PPC-V) had significantly higher odds of having ≥50% ICAS. This association remained significant after adjusting for confounding variables: age, gender, race, hypertension, diabetes, dyslipidemia, 3-level education, and smoking status. There was no association between dental caries (DS and DRS) and ICAS <50% and ≥50%. Conclusion: We report significant associations between mild-moderate tooth loss, severe tooth loss, and severe PD with <50% ICAS as well as an association between extensive gingivitis and ≥50% ICAS. We did not find an association between dental caries and ICAS.

A narrative review of imaging tools for imaging subgingival calculus.

The conventional method of detecting subgingival calculus involves using a periodontal probe to sense tactile differences on the dental root surface. Although efficient, this method can result in false positives and false negatives. This literature review explores alternative detection techniques that can detect subgingival calculus with improved accuracy and consistency. The accumulation of dental calculus below the gingival margin can foster periodontitis-inducing bacterial growth. Conventional methods of locating subgingival calculus are often inaccurate and highly dependent on clinician skill. This literature review evaluates techniques used to improve the accuracy of imaging and detecting subgingival calculus. Google Scholar, PubMed and PubMed Central databases were searched for peer-reviewed original articles evaluating subgingival calculus imaging and detection techniques. A total of 46 relevant articles ranging from 1981 to 2021 were included. This narrative review discusses the subgingival calculus detection and imaging capabilities of periodontal endoscopy in an in vivo study and of optical coherence tomography (OCT), fluorescence spectroscopy, and differential reflectometry in in vitro settings. Each technique has unique benefits and limitations that distinguishes it from the others. In vitro studies have revealed that techniques including periodontal endoscopy, OCT, fluorescence spectroscopy, or differential reflectometry allow for a more accurate diagnosis of subgingival calculus deposits in comparison to detection via periodontal probing. Despite the improved results, the common limitations of these techniques include longer operation times and expensive equipment. Further studies are needed to transition these imaging and detection methods to clinical environments.

IN VITRO EVALUATION OF THE ANTIMICROBIAL ACTIVITY OF FIVE HERBAL EXTRACTS AGAINST STREPTOCOCCUS MUTANS

Background: The emergence and extend of antibiotic resistance, together with the development of new strains of illness causes, are of enormous alarm to the global health community. Successful treatment of a illness involves the development of new pharmaceuticals or some promise source of novel drugs. Universally make use of medicinal plants of our community could be an outstanding source of drugs to fight off dental caries. This study is focused on discovering the antibacterial properties of the plants that are frequently being used as traditional medications. Methods: Five methanol extracts from Salvia officinalis, Commiphora myrrha, Boswellia carteril, Saussurea lappa and Dracaena cinnabari were examined for their antibacterial activities against most common bacterial oral pathogen, Streptococcus mutans. The antibacterial testing was carried out by using the disc diffusion and broth micro-dilution assays. Results: Methanol extracts of the five plants were effective against Streptococcus mutans with diameter zone of inhibition ranging from 63.6 to 21.0 mm. The results of the microdilution assay confirmed that the Salvia officinalis, Commiphora myrrha, Saussurea lappa and Dracaena cinnabari were effective against the Streptococcus mutans, exhibiting MIC values, ranging from 0.310 to 0.156 mg/ml. Conclusion: The results of our study indicate that the methanol extracts of plants used in this study have an antibacterial effect even at low concentration against the carcinogenic Streptococcus mutans bacteria, and they may be possible to combat Streptococcus mutans to increase the effectiveness of oral hygiene practices by incorporating the extracts of these plants into anti-caries such as Toothpastes and mouthwash. Peer Review History: Received: 18 January 2022; Revised: 13 February; Accepted: 8 March, Available online: 15 March 2022 Academic Editor: Dr. Asia Selman Abdullah, Pharmacy institute, University of Basrah, Iraq, asia_abdullah65@yahoo.com UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. Sangeetha Arullappan, Universiti Tunku Abdul Rahman, Malaysia, sangeetha@utar.edu.my Prof. Dr. Ali Gamal Ahmed Al-kaf, Sana'a university, Yemen, alialkaf21@gmail.com Similar Articles: ASSOCIATION BETWEEN THE STREPTOCOCCUS MUTANS BIOFILM FORMATION AND DENTAL CARIES EXPERIENCE AND ANTIBIOTICS RESISTANCE IN ADULT FEMALES ANALYSIS OF BIOFILMS FOR STREPTOCOCCUS MUTANS FROM DENTAL ROOT SURFACES OF ADULT PATIENTS WITH ROOT CARIES

ANALYSIS OF BIOFILMS FOR STREPTOCOCCUS MUTANS FROM DENTAL ROOT SURFACES OF ADULT PATIENTS WITH ROOT CARIES

Background and objectives: Knowledge of the pathogenicity of the primary etiological factor of root caries, the microbial biofilm, might provide important information for the development of diagnosis and treatment strategies. This study assessed the numbers and revealed the proportion of Mutans streptococci , which is potential important cariogenic organisms, in biofilms collected from lesions at root surfaces with active caries lesions (ARC), inactive caries lesions, and sound root surfaces (SRS).&#x0D; Material and methods: Samples were cultured in MSB agar for Mutans streptococci counts, and brain-heart infusion agar for total viable anaerobic counts. After incubation, the number of colony-forming units (CFUs) was determined and compared between groups by the Mann-Whitney U test with a significance level set at 95%. The proportion of counts of Mutans streptococci in the total viable microorganisms was also analyzed by Chi-square test. 108 samples (36 from each surface) from 36 patients were cultured and analyzed.&#x0D; Results: The mean±SD for the counts of active root caries lesions was 7.47±9.89 10, significantly higher than that of inactive root caries lesions (2.5±0.97) and sound root surfaces (3.03±0.71). In conclusion, a trend towards higher counts was evident for ARC. In the ARC lesions among the dominant oral anaerobic bacteria, we could not identify streptococcal colonies (unspecified) in 11% while in IRC lesions it occurred in 47%, and SRS it occurred in 47%. In addition, in ARC the samples were ≥0.1-≥10 (CFU x10) ≥0.1-≥10 colonies of Streptococcus mutans.&#x0D; Conclusion: In conclusion, a trend towards higher counts was evident for ARC and for most samples, the proportion of Streptococcus mutans was low relative to the viable number of total viable anaerobic microorganisms.&#x0D; &#x0D; Peer Review History: &#x0D; Received: 5 September 2021; Revised: 10 October; Accepted: 24 October, Available online: 15 November 2021&#x0D; Academic Editor: Ahmad Najib, Universitas Muslim Indonesia, Indones&#x0D; UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. &#x0D; Received file: Reviewer's Comments:&#x0D; Average Peer review marks at initial stage: 6.0/10&#x0D; Average Peer review marks at publication stage: 7.0/10&#x0D; Reviewers:&#x0D; Dr. Rawaa Souhil Al-Kayali, Aleppo University, Syria, rawah67@hotmail.com&#x0D; Dr. Tamer Elhabibi, Suez Canal University, Egypt, tamer_hassan@pharm.suez.edu.eg&#x0D; Similar Articles:&#x0D; ASSOCIATION BETWEEN THE STREPTOCOCCUS MUTANS BIOFILM FORMATION AND DENTAL CARIES EXPERIENCE AND ANTIBIOTICS RESISTANCE IN ADULT FEMALES&#x0D; CLINICAL FEATURES, AGE AND SEX DISTRIBUTIONS, RISK FACTORS AND THE TYPE OF BACTERIA ISOLATED IN PERIODONTITIS PATIENTS IN SANA'A, YEMEN

Selective Antimicrobial Therapies for Periodontitis: Win the "Battle and the War".

Traditional antimicrobial therapies for periodontitis (PD) have long focused on non-selective and direct approaches. Professional cleaning of the subgingival biofilm by instrumentation of dental root surfaces, known as scaling and root planning (SRP), is the mainstay of periodontal therapy and is indisputably effective. Non-physical approaches used as adjuncts to SRP, such as chemical and biological agents, will be the focus of this review. In this regard, traditional agents such as oral antiseptics and antibiotics, delivered either locally or systemically, were briefly reviewed as a backdrop. While generally effective in winning the “battle” against PD in the short term, by reducing its signs and symptoms, patients receiving such therapies are more susceptible to recurrence of PD. Moreover, the long-term consequences of such therapies are still in question. In particular, concern about chronic use of systemic antibiotics and their influence on the oral and gut microbiota is warranted, considering antibiotic resistance plasmids, and potential transfer between oral and non-oral microbes. In the interest of winning the “battle and the war”, new more selective and targeted antimicrobials and biologics for PD are being studied. These are principally indirect, blocking pathways involved in bacterial colonization, nutrient acquisition, inflammation or cellular invasion without directly killing the pathogens. This review will focus on current and prospective antimicrobial therapies for PD, emphasizing therapies that act indirectly on the microbiota, with clearly defined cellular and molecular targets.

In vitro study on conditioned dental root surfaces: evaluation of wettability, smear layer, and blood clot adhesion.

The aim was to investigate the efficacy of citric acid and ethylenediaminetetraacetic acid (EDTA)-based treatments on smear layer removal and blood clot formation and stabilization. After scaling and root planing, 126 root samples were divided into seven groups treated with: deionized water; saline; citric acid solution; Ultradent Citric Acid gel; EDTA solution; EDTA-based PrefGel; or untreated. Each group was divided into three subgroups: I for the evaluation of smear layer removal and surface wettability, II and III for the evaluation of blood clot formation and stabilization in static or dynamic rinsing conditions. Conditioning agent treatments increased surface wettability with respect to untreated samples (Ultradent: 45 ± 1 degrees, P = 6.2 × 10-3; EDTA: 36 ± 5 degrees, P = 8.9 × 10-7; PrefGel: 47 ± 7 degrees, P = 3.2 × 10-2). Smear layer removal (30% to 60% with respect to untreated samples) was observed for all the conditioning agents. Clot was absent on untreated samples and samples treated with deionized water. Clot quality was significantly higher for samples treated with conditioning agents (P < .05) and similar between group II and III (P > .05). A statistically significant difference (P = .027) was observed for clot coverage of the saline group, comparing static and dynamic rinsing, confirming the positive effect of treatments on clot stabilization. The use of conditioning agents improves smear layer removal and clot formation and stabilization with respect to scaling and root planing procedure only, which is, however, considered an essential procedure to promote wound healing in periodontal surgery.

An Experimental and Clinically Controlled Study of the Prevention of Dental Caries Using 1.23% Fluoride Gel in Elderly Patients.

ABSTRACTAim:To describe the enamel and dentin fluoride mineralization process in practical application and assess the fluoride gel (NaF 1.23%) effectiveness in dental caries prevention for elderly patients.Materials and Methods:Two different types of study were applied: (a) experimental study of fluoride mineralization of enamel and dentin in vitro; (b) clinical controlled interventional studies of the effectiveness in dental caries prevention using 1.23% fluoride gel. Experimental research was performed in laboratory conditions. Teeth of the elderly extracted due to dental diseases served as research objects. Enamel surface and dental root surface were examined under a scanning electron microscope (SEM) before and after demineralization with 37% phosphoric acid within 15 s, as well as after remineralization with toothpaste and 1.23% fluoride gel. Controlled clinical research included 218 older people divided into two groups (intervention group, n = 106; control group, n = 112). In the intervention group, the application of the gel lasts 4 min in the morning for 18 months. The control group received adult P/S toothpaste and a P/S toothbrush. The DIAGNOdent device was used to assess damage both before and after demineralization. For the clinical evaluation of dental caries, international caries detection and assessment system (ICDAS) has been used. Decay missing-filled index (DMFT), effective index (Ef-I), and intervention index (In-I) were determined. Statistical data were analyzed using Mann–Whitney U test and χ2 test. Differences were considered significant at P < 0.05.Results:An SEM image of the enamel surface and dental root surface after teeth remineralization with fluoride gel shows a hard enamel surface without cracks, even in color and structure. After brushing with toothpaste, numerous cracks remain on the surface of the enamel, and the surface layer of the enamel with a depth of 9.64 microns remains damaged without remineralization. After 18 months of intervention, the rate of dental caries in the control group increased from 42.1% to 68.8%, and in the intervention group it increased from 30.8% to 17.0%. A comparison of the 1.23% fluoride gel with toothpaste shows that the former exhibits performance in protecting teeth from decay and it is 108.2% more effective than the latter.Conclusions:Practical experiments proved the function of remineralizing the enamel and dentin of 1.23% fluoride gel on the teeth of the elderly. Intervention research has proven the performance of preventing dental decay from 1.23% fluoride gel for the elderly in question.

Dental root surface treatment with ethylenediaminetetraacetic acid does not improve enamel matrix derivative peptide treatment within intrabony defects: a retrospective study.

Dental root surface treatment with ethylenediaminetetraacetic acid does not improve enamel matrix derivative peptide treatment within intrabony defects: a retrospective study.

Randomized Clinical Trial on Preventing Root Caries among Community-Dwelling Elders.

Dental root caries is a common disease among elders. More efforts on preventing this disease are needed. Silver diammine fluoride (SDF) is known to prevent dental caries in primary teeth. However, clinical evidence of its efficacy in preventing root surface caries is limited. This clinical trial aimed to compare the effectiveness of SDF in preventing root caries among elders in a water fluoridated area. A total of 323 elders who had at least 5 teeth with exposed root surfaces and who had self-care ability were randomly allocated into 3 intervention groups: group 1 (placebo control), annual application of tonic water; group 2, annual application of SDF solution; group 3, annual application of SDF solution, immediately followed by potassium iodide (KI) solution. Oral hygiene instructions and fluoride toothpaste were provided to all subjects. Status of dental root surface was assessed every 6 mo by the same independent examiner. After 30 mo, 257 (79.6%) elders were reviewed. The mean numbers of root surface with new caries experience in the control, SDF, and SDF/KI groups were 1.1, 0.4, and 0.5, respectively (analysis of variance, P < 0.001). Scheffe's multiple comparison showed that elders who received placebo developed more new root caries lesions ( P < 0.05), while the difference between the SDF and SDF/KI groups was not statistically significant ( P > 0.05). Moreover, elders who had higher visible plaque index scores at 30-mo examination (analysis of covariance, P < 0.001) and those who had higher baseline DMFT scores (analysis of covariance, P = 0.005) developed more new root caries. It is concluded that annual application of SDF or SDF/KI solution is effective in preventing root caries among community-dwelling elders in a fluoridated area ( ClinicalTrials.gov NCT02360124). Knowledge Transfer Statement: Annual topical application of silver diammine fluoride or silver diammine fluoride / potassium iodide solution is effective in preventing dental root surface caries among community-dwelling elders in a fluoridated area.

Synergistic Effects of a Calcium Phosphate/Fibronectin Coating on the Adhesion of Periodontal Ligament Stem Cells Onto Decellularized Dental Root Surfaces.

This study aimed to enhance the attachment of periodontal ligament stem cells (PDLSCs) onto the decellularized dental root surface using surface coating with fibronectin and/or calcium phosphate (CaP) and to evaluate the activity of PDLSCs attached to a coated dental root surface following tooth replantation. PDLSCs were isolated from five dogs, and the other dental roots were used as a scaffold for carrying PDLSCs and then assigned to one of four groups according to whether their surface was coated with CaP, fibronectin, CaP/fibronectin, or left uncoated (control). Fibronectin increased the adhesion of PDLSCs onto dental root surfaces compared to both the control and CaP-coated groups, and simultaneous surface coating with CaP and fibronectin significantly accelerated and increased PDLSC adhesion compared to the fibronectin-only group. On in vivo tooth replantation, functionally oriented periodontal new attachment was observed on the CaP/fibronectin-coated dental roots to which autologous PDLSCs had adhered, while in the control condition, dental root replantation was associated only with root resorption and ankylosis along the entire root length. CaP and fibronectin synergistically enhanced the attachment of PDLSCs onto dental root surfaces, and autologous PDLSCs could produce de novo periodontal new attachment in an experimental in vivo model.

フルオロアルミノシリケートガラス分散液による歯根面への プラーク付着防止効果

露出した根面へのプラークの付着は歯周炎だけでなく，歯根面う蝕の原因ともなり歯周病患者を管理していく上での大きな障害の 1 つである。知覚過敏抑制材であるフルオアルミノシリケートガラス分散液（ナノシール®）は歯根面上にナノ粒子層を形成し耐酸性を向上させ，歯根表面の電荷を変えることによりプラークの沈着を抑制できることが考えられる。 本研究ではナノシール®を象牙質表面に応用した場合のプラーク付着抑制効果について調べることを目的とした。牛歯片上でS. mutans を 48 時間培養し，水洗後にバイオフィルム形成状態を走査型電子顕微鏡（SEM）にて観察した。さらに，前歯部に歯根露出歯を有する患者（10 名）にナノシール®を塗布し，2 週，4 週間後の根面へのプラーク付着状態についてランダム割付 2 重盲検法で評価した。 その結果，ナノシール®未塗布牛歯片では明らかなバイオフィルムの形成を認めたが，ナノシール®塗布部では細菌が散在して認められた。歯根露出を有する患者のプラーク付着率はナノシール®群において低い傾向を示したが有意差を認めなかった。in vitro においてナノシール®のバイオフィルム付着抑制効果が示されたが，今回の実験では水洗後の状態を見ていることから，バイオフィルムと歯面との付着力が落ちていたことが考えられる。 今後はin vivoにおけるプラーク付着力について検討していく予定である。 日本歯周病学会会誌（日歯周誌）56(1)：25-31，2014

USING CELLULAR AUTOMATA EXPERIMENTS TO MODEL PERIODONTITIS: A FIRST STEP TOWARDS UNDERSTANDING THE NONLINEAR DYNAMICS OF THE DISEASE

Cellular automata (CA) are time and space discrete dynamical systems that can model biological systems. The aim of this study is to simulate by CA experiments how the disease of periodontitis propagates along the dental root surface. Using a Moore neighborhood on a grid copy of the pattern of periodontal ligament fibers (PDLF) supporting and anchoring the teeth to bone, we investigate the fractal structure of the associated pattern using all possible outer-totalistic CA rules. On the basis of the propagation patterns, CA rules are classified in three groups, according to whether the disease was spreading, remaining constant or receding. These are subsequently introduced in a finite state Markov model as probabilistic "state-rules" and the model is validated using datasets retrieved from previous studies. Based on the maximum entropy production principle, we identified the "state-rule" that most appropriately describes the PDLF pattern, showing a power law distribution of periodontitis propagation rates with exponent 1.3. Entropy rates and mutual information of Markov chains were estimated by extensive data simulation. The scale factor of the PDLF used to estimate the conditional entropy of Markov chains was seen to be nearly equal 1.85. This possibly reflects the fact that a dataset representing tooth percentage with bone loss equal to 50% or more of their root length, is found to have a fractal dimension (FD) of about 1.84. Similarly, datasets of serum neutrophil, basophil, eosinophil, monocyte counts and IgG, IgA, IgM levels taken from periodontitis patients, showed a FD ranging from 1.82 to 1.87. Our study presents the first mathematical model to our knowledge that suggests periodontitis is a nonlinear dynamical process. Moreover, the model we propose implies that the entropy rate of the immune-inflammatory host response dictates the rate of periodontitis progression. This is validated by clinical data and suggests that our model can serve as a basis for detecting periodontitis susceptible individuals and shaping prognosis for treated periodontitis patients.

Synthesis and evaluation of a novel injectable and water-swelling gingival displacement materials

To synthesize and evaluate a novel injectable and water-swelling gingival displacement materials. A kind of water-swelling polymer, kaolin and aluminum chloride were mechanically mixed at certain ratio in water solution, resulting to a novel paste materials for gingival displacement. Then, its stability in aqueous solution and water swelling properties were evaluated in vitro. The effect on gingival displacement was evaluated by animal experiments in dogs. A commercial gingival displacement materials paste of Expasyl was used as control. While contacting with water, the novel gingival displacement paste did not collapse, maintained its integrity structure, and could expand for adsorbing water. Animal experiments in dogs showed that the materials could lead to displace the gingival margins from the dental root surfaces. The novel injectable and expanded gingival displacement material is efficient to retract free gingival margin with potential clinical application.

Evaluation of apical preparations performed with ultrasonic diamond and stainless steel tips at different intensities using a scanning electron microscope in endodontic surgery

Objective: The objective of our study is to analyse (with the help of scanning electron microscopes) the quality of the dental root surface and the appearance of dental cracks after performing apical preparations using two diffe-rent types of ultrasonic tips. Study design: We used 32 single-rooted teeth that underwent a root canal and apical resection. Afterwards, the teeth were divided into 4 groups of 8 teeth each, with preparations of the apical cavities in the following manner: Group 1: stainless steel ultrasonic tip at 33KHz. Group 2: stainless steel ultrasonic tip at 30KHz. Group 3: diamond ultrasonic tip at 30KHz. Group 4: diamond ultrasonic tip at 33 KHz. The quality of the root surface and the presence of cracks were evaluated by one single observer using a scanning electron microscope. Results: All of the teeth in our study had cracks after the apical preparations. The mean number of cracks per tooth ranged between 6.1±1.9 (group 1) and 3.5±2.4 (group 4), with a significantly higher number found in the groups that used stainless steel tips (P=.03). The types of cracks produced involved: 8 complete cracks (4.5%), 167 incomplete cracks (94.4%), and 2 intradentinal cracks (1.1%), with no significant differences observed between the different frequencies used for each group. Conclusions: Stainless steel ultrasonic tips provoked a larger number of cracks than diamond tips. The frequency of vibration used did not have any effect on the number of cracks found. Key words:Apicoectomy, scanning electron microscope, therapeutic ultrasound, endodontic surgery, dentinal crack.

Tooth root morphology as an indicator for dietary specialization in carnivores (Mammalia: Carnivora)

The Carnivora occupy a wide range of feeding niches in concordance with the enormous diversity in their skull and dental form. It is well established that differences in crown morphology are linked to variations in the material properties of the foods ingested and masticated. However, how tooth root form is related to dietary specialization is less well known. In the present study, we investigate the relationship between tooth root morphology and dietary specialization in terrestrial carnivores (canids, felids, hyaenids, and ursids). We specifically address the question of how variation in tooth root surface area is related to bite force potentials as one of the crucial masticatory performance parameters in feeding ecology. We applied computed tomography imaging to reconstruct and quantify dental root surface area in 17 extant carnivore species. Moreover, we computed maximal bite force at several tooth positions based on a dry skull model and assessed the relationship of root surface area to skull size, maximal bite force, food properties, and prey size. We found that postcanine tooth root surface areas corrected for skull size serve as a proxy for bite force potentials and, by extension, dietary specialization in carnivores. Irrespective of taxonomic affinity, species that feed on hard food objects have larger tooth roots than those that eat soft or tough foods. Moreover, carnivores that prey on large animals have larger tooth root surface areas. Our results show that tooth root morphology is a useful indicator of bite force production and allows inferences to be made about dietary ecology in both extant and extinct mammals.

Special considerations for orthodontic treatment in patients with root resorption

Background Orthodontic treatment needs good consideration especially when there are unfavorable conditions for orthodontic treatment, such as periodontal diseases or tooth with root resorption. Root resorption should not become worse due to orthodontic treatment., All risk factors should be eliminated before orthodontic treatment is started. Otherwise, the goal of orthodontic treatment could be difficult to achieve because of poor dental and or oral health. Purpose The purpose of this study was to learn more about mechanical factors that could worsen the root resorption that has already been there or even provoke root resorption to develop during orthodontic treatment. Reviews Resorption of dental root surface is the condition in which cementum is depraved and the damage could also include dentin of dental root. It can occur either physiologically or pathologically due to some causes. The occurrence of the root resorption is suspected because of the biological factor, the tooth condition, the supportive tissue and the mechanical factors. Panoramic x-ray which routinely used to support diagnose in orthodontic cases, can detect root resorption in general, although sometimes periapical x-ray with parallel technique is needed to enhance the diagnosis. Before starting a treatment, the risk factors that suspected as the causes of root resorption should be eliminated, thus the mechanical treatment can be calculated. Conclusion Orthodontic treatment in patient with root resorption should not escalate the root resorption which already occurs. The treatment should be done effectively by using optimal forces. Giving discontinued forces and avoiding intrusion and torque movements could reduce the risk factors of root resorption.

Nd:YAG Laser Improves Biocompatibility of Human Dental Root Surfaces

Our goal was to compare the in vivo biocompatibility of dental root surfaces submitted to four different treatments after tooth avulsion followed by implantation into rat subcutaneous tissue. Dental root surface preparation prior to replanting teeth remains a challenge for endodontists. Root surface changes made by Nd:YAG irradiation could be an alternative preparation. Forty-eight freshly extracted human dental roots were randomly divided into four treatment groups prior to implantation into rat subcutaneous tissue: G1, dry root, left in the environment up to 3 h; G2, the same treatment as G1, followed by a soaking treatment in a 2.4% sodium fluoride solution (pH 5.5); G3, root soaked in physiologic saline after avulsion for 72 h; G4, the same treatment as G1, followed by Nd:YAG laser irradiation (2.0 W, 20 Hz, 100 mJ, and 124.34 J/cm(2)). The animals were sacrificed 1, 7, and 45 d later. Histological and scanning electron microscopy analyses were done. All dental roots were involved and in intimate contact with connective tissue capsules of variable thicknesses. Differences were observed in the degree of inflammation and in connective tissue maturation. In G3 the inflammatory infiltrate was maintained for 45 d, whereas the Nd:YAG laser irradiation (G4) led to milder responses. The overall aspects of the root surfaces were similar, except by the irradiated roots, where fusion and resolidification of the root surface covering the dentinal tubules were observed. Nd:YAG laser irradiation improves the biocompatibility of dental root and thus could be an alternative treatment of dental root prior to replantation.

Periodontal regeneration with multi-layered periodontal ligament-derived cell sheets in a canine model

Periodontal regeneration has been challenged with chemical reagents and/or biological approaches, however, there is still no sufficient technique that can regenerate complete periodontium, including alveolar bone, cementum, and well-oriented collagen fibers. The purpose of this study was to examine multi-layered sheets of periodontal ligament (PDL)-derived cells for periodontal regeneration. Canine PDL cells were isolated enzymatically and expanded in vitro. The cell population contained cells capable of making single cell-derived colonies at an approximately 20% frequency. Expression of mRNA of periodontal marker genes, S100 calcium binding protein A4 and periostin, was observed. Alkaline phosphatase activity and gene expression of both osteoblastic/cementoblastic and periodontal markers were upregulated by osteoinductive medium. Then, three-layered PDL cell sheets supported with woven polyglycolic acid were transplanted to dental root surfaces having three-wall periodontal defects in an autologous manner, and bone defects were filled with porous β-tricalcium phosphate. Cell sheet transplantation regenerated both new bone and cementum connecting with well-oriented collagen fibers, while only limited bone regeneration was observed in control group where cell sheet transplantation was eliminated. These results suggest that PDL cells have multiple differentiation properties to regenerate periodontal tissues comprising hard and soft tissues. PDL cell sheet transplantation should prove useful for periodontal regeneration in clinical settings.

The influence of water temperature during toothbrushing on root dentine: An in vitro study

The use of cold water during toothbrushing can cause dentine sensitivity and, to avoid this painful stimulus, some patients used to rinse their mouths with warm water when brushing. Thus, the objective of this study was to determine the effect of water temperature on the dental root surface during toothbrushing. Fragments of bovine dental roots were submitted to 15,000 strokes in a toothbrushing machine using a slurry of toothpaste/water, medium brushes, and a 200-g load. They were randomly divided into two groups: toothbrushing with cold water or with hot water. Tooth wear was measured by loss of weight and by tissue height. The weight and height data obtained in 17 and 10 replicas respectively are presented as mean +/- standard error of mean. The data were compared using the Kolgomorov-Smirnof (Lilliefors) test followed by one-way ANOVA. The level of significance was 5% (P < 0.05). There were no significant differences between the two experimental groups. The mean percentages of weight losses were 5.61 +/- 1.66 for cold water and 6.25 +/- 1.98 for hot water. The mean dentine height losses were 51.02 +/- 15.92 microm for cold water and 63.54 +/- 17.75 microm for hot water. The use of warm water during toothbrushing promoted root dentine wear similar to that produced by the use of cold water. The results suggest that warm or cold water may be used during toothbrushing without any additional damage to the patients' dental hard tissues.