In past decades, morphologic, molecular, and cellular mechanisms that govern tooth development have been extensively studied. These studies demonstrated that the same signaling pathways regulate ...development of the primary and successional teeth. Mutations of these pathways lead to abnormalities in tooth development and number, including aberrant tooth shape, tooth agenesis, and formation of extra teeth. Here, we summarize the current knowledge on the development of the primary and successional teeth in animal models and describe some of the common tooth abnormalities in humans.
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CMK, NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
The tooth is an intricate composition of precisely patterned, mineralized matrices and soft tissues. Mineralized tissues include enamel (produced by the epithelial cells called ameloblasts), dentin ...and cementum (produced by mesenchymal cells called odontoblasts and cementoblasts, respectively), and soft tissues, which include the dental pulp and the periodontal ligament along with the invading nerves and blood vessels. It was perceived for a very long time that teeth primarily serve an esthetical function. In recent years, however, the role of healthy teeth, as well as the impact of oral health on general well-being, became more evident. Tooth loss, caused by tooth decay, congenital malformations (tooth agenesis), trauma, periodontal diseases, or age-related changes, is usually replaced by artificial materials which lack many of the important biological characteristics of the natural tooth. Human teeth have very low to almost absent regeneration potential, due to early loss of cell populations with regenerative capacity, namely stem cells. Significant effort has been made in recent decades to identify and characterize tooth stem cells, and to unravel the developmental programs which these cells follow in order to generate a tooth.
Aim
To evaluate retrospectively the prevalence of vertical root fractures (VRFs) in a cohort of patients during apical surgery and the factors possibly associated with VRF.
Methodology
The sample ...consisted of 944 root filled teeth belonging to 768 patients (49.3% males and 50.7% females; mean age 43.5 ± 11.2 years, range 22–68 years), consecutively referred for endodontic surgery over a six‐year period. All patients underwent a clinical assessment of their signs and symptoms. Periapical radiographs of teeth that were candidates for endodontic surgery were taken. Sixty‐eight teeth with VRF were identified. Vertical root fractures were identified in pre‐surgical screenings in 32 cases (47.1%), and these did not undergo surgery. Another 36 cases of VRF were noted during the intervention for root‐end resection. The influence of posts, post type, tooth type, periodontal probing defects, spontaneous pain, sinus tract and follow‐up duration was assessed using a logistic regression analysis.
Results
Vertical root fractures occurred significantly more frequently (P < 0.001) when a post was present (61 VRF out of 377 teeth with post, prevalence 16.2%) than in teeth without a post (1.2%). Threaded posts and cast posts were significantly more involved in VRF than fibre, silica or carbide posts (P < 0.001). Most fractures (80.9%) occurred 1–5 years after root canal treatment. Sinus tracts, probing defects and spontaneous pain were significantly more associated with VRF cases than with nonfractured teeth.
Conclusions
In the present group of teeth, the major risk for VRF was represented by posts retained by actively engaging the canal via mechanical design (thread) or by frictional fit (cast).
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BFBNIB, CMK, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Background
With the increased demand for whiter teeth, home‐based bleaching products, either dentist‐prescribed or over‐the‐counter products have been exponentially increasing in the past few ...decades. This is an update of a Cochrane Review first published in 2006.
Objectives
To evaluate the effects of home‐based tooth whitening products with chemical bleaching action, dispensed by a dentist or over‐the‐counter.
Search methods
Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 12 June 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 6) in the Cochrane Library (searched 12 June 2018), MEDLINE Ovid (1946 to 12 June 2018), and Embase Ovid (1980 to 12 June 2018). The US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (12 June 2018) and the World Health Organization International Clinical Trials Registry Platform (12 June 2018) were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.
Selection criteria
We included in our review randomised controlled trials (RCTs) which involved adults who were 18 years and above, and compared dentist‐dispensed or over‐the‐counter tooth whitening (bleaching) products with placebo or other comparable products.
Quasi‐randomised trials, combination of in‐office and home‐based treatments, and home‐based products having physical removal of stains were excluded.
Data collection and analysis
Two review authors independently selected trials. Two pairs of review authors independently extracted data and assessed risk of bias. We estimated risk ratios (RRs) for dichotomous data, and mean differences (MDs) or standardised mean difference (SMD) for continuous data, with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach.
Main results
We included 71 trials in the review with 26 studies (1398 participants) comparing a bleaching agent to placebo and 51 studies (2382 participants) comparing a bleaching agent to another bleaching agent. Two studies were at low overall risk of bias; two at high overall risk of bias; and the remaining 67 at unclear overall risk of bias.
The bleaching agents (carbamide peroxide (CP) gel in tray, hydrogen peroxide (HP) gel in tray, HP strips, CP paint‐on gel, HP paint‐on gel, sodium hexametaphosphate (SHMP) chewing gum, sodium tripolyphosphate (STPP) chewing gum, and HP mouthwash) at different concentrations with varying application times whitened teeth compared to placebo over a short time period (from 2 weeks to 6 months), however the certainty of the evidence is low to very low.
In trials comparing one bleaching agent to another, concentrations, application method and application times, and duration of use varied widely. Most of the comparisons were reported in single trials with small sample sizes and event rates and certainty of the evidence was assessed as low to very low. Therefore the evidence currently available is insufficient to draw reliable conclusions regarding the superiority of home‐based bleaching compositions or any particular method of application or concentration or application time or duration of use.
Tooth sensitivity and oral irritation were the most common side effects which were more prevalent with higher concentrations of active agents though the effects were mild and transient. Tooth whitening did not have any effect on oral health‐related quality of life.
Authors' conclusions
We found low to very low‐certainty evidence over short time periods to support the effectiveness of home‐based chemically‐induced bleaching methods compared to placebo for all the outcomes tested.
We were unable to draw any conclusions regarding the superiority of home‐based bleaching compositions or any particular method of application or concentration or application time or duration of use, as the overall evidence generated was of very low certainty. Well‐planned RCTs need to be conducted by standardising methods of application, concentrations, application times, and duration of treatment.
Abstract Introduction The aims of this study were to analyze the distribution and characteristic features of cracked teeth and to evaluate the outcome of root canal treatments (RCTs) for cracked ...teeth. The prognostic factors for tooth survival were investigated. Methods Over the 5-year study period, 175 teeth were identified as having cracks. Data were collected regarding the patients' age, sex, tooth type, location and direction of cracks, probing depth, pulp vitality, type of restoration, cavity classification, opposing teeth, and previous endodontic treatment history. Cracked teeth were managed via various treatment methods, and the 2-year survival rate after RCT was analyzed using the Kaplan-Meier method in which significance was identified using the log-rank test. Possible prognostic factors were investigated using Cox multivariate proportional hazards modeling. Results One hundred seventy-five teeth were diagnosed with cracks. Most of the patients were aged 50–60 years (32.0%) or over 60 (32.6%). The lower second molar was the most frequently (25.1%) affected tooth. Intact teeth (34.3%) or teeth with class I cavity restorations (32.0%) exhibited a higher incidence of cracks. The 2-year survival rate of 88 cracked teeth after RCT was 90.0%. A probing depth of more than 6 mm was a significant prognostic factor for the survival of cracked teeth restored via RCT. The survival rate of root-filled cracked teeth with a probing depth of more than 6 mm was 74.1%, which is significantly lower than that of teeth with probing depths of less than 6 mm (96.8%) ( P = .003). Conclusions Cracks were commonly found in lower second molars and intact teeth. RCT was a reliable treatment for cracked teeth with a 2-year survival rate of 90.0%. Deep probing depths were found to be a significant clinical factor for the survival of cracked teeth treated with RCT.
Traumatic injuries to the primary dentition present special problems and the management is often different as compared with the permanent dentition. The International Association of Dental ...Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialities were included in the task group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care for management of primary teeth injuries. The IADT cannot and does not guarantee favorable outcomes from strict adherence to the guidelines, but believe that their application can maximize the chances of a positive outcome.
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BFBNIB, CMK, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
To assess the feasibility of detecting and monitoring early erosive tooth wear using a 3D intraoral scanner (IOS) aided by specific software.
Extracted sound permanent teeth were assembled in two ...shortened artificial dental arches and scanned at different intervals with an IOS (3Shape TRIOS® 3) before and after an erosion/abrasion protocol (i.e. 1 h up to 24 h immersion in citric acid solution and subsequent brushing). The 3D models obtained at consecutive time points were superimposed with the baseline model using dedicated software (3Shape TRIOS® Patient Monitoring, version 2.1.1.0) and reference surface alignment. Surface profile differences between the baseline 3D model and the respective models from different time points were expressed as tooth substance loss.
Non-parametric tests were used to assess the significance of tooth substance loss at different time points. Spearman’s correlation was applied between the tooth substance loss at the end of each erosion/abrasion cycle and the immersion time in acid.
Significant tooth substance loss (0.08 mm, IQR = 0.05) was detected by the software after 3 h of erosive-abrasive challenge (p = 0.045). The overall median loss increased gradually from baseline to 24 h showing a strong correlation with the immersion time in acid (rs = 0.971, p < 0.01).
The use of an IOS aided by specific software showed good performance for early detection and monitoring of tooth wear in vitro and has promising potential for in vivo application.
Detection and monitoring of early erosive tooth wear can be reliably aided by intraoral scanning supported by specific software. The measurement error and uncertainty involved in this method should be taken into consideration when interpreting the tooth substance loss measurements. Furthermore, presuming the difficulty in defining reference surfaces in vivo, clinical validation is needed to determine the system’s in vivo performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To investigate the prevalence of tooth wear and associated factors in adults from the 1982 Pelotas Birth Cohort.
A subsample of the 5,914 individuals from the 1982 Pelotas Birth Cohort was randomly ...selected to be interviewed and clinically examined at the age of 31. Tooth wear was evaluated using a simplified version of the Tooth Wear Index (TWI), considering the absence or presence of tooth wear in dentin of first molars and anterior teeth (incisors and canines). Independent variables were socioeconomic, demographic, unhealthy behavior, and mental health. Crude and adjusted Poisson regression models were employed. A significant level of P ≤ 0.05 was adopted.
A total of 537 individuals were evaluated. A tooth wear prevalence of 61.6% was observed. Females presented a statistically significant lower tooth wear in dentin prevalence ratio (PR) compared to males in the adjusted analysis (PR 0.76; 95% CI: 0.67–0.86). Acid beverage consumption (PR 1.22; 95% CI: 1.01–1.49) and consumption of alcoholic beverages (PR 1.19; 95% CI: 1.04–1.35) were positively associated with tooth wear.
Almost 2/3 of the surveyed individuals presented tooth wear in dentin. Being a male, higher consumption of alcohol and acidic beverages were factors associated with tooth wear.
: There was a high prevalence of tooth wear in dentin in the adult population. Data has also shown the etiological complexity of tooth wear, reinforcing the importance of an early diagnosis and the establishment of preventive measures to decrease the potentially hazardous effect of tooth wear over time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To assess the effect of activated charcoal toothpastes on enamel and dentin erosive wear.
Ninety enamel and dentin slabs were randomly distributed into 9 experimental groups (n = 10/substrate): ...Artificial saliva (negative control); Elmex Caries (EXC – 1400 ppm F− as AmF, reference toothpaste without charcoal); Colgate Luminous White Activated Charcoal (CLW – 1000 ppm F− as MFP); Colgate Natural Extracts (CNE – 1450 ppm F- as NaF); Oral-B 3D White Mineral Clean (OMC - 1100 ppm F− as NaF); Curaprox Black is White (CBW - 950 ppm F− as MFP); Bianco Carbon (BIC - no F−); Natural Suavetex (NSX - no F−); Oralgen Nupearl Advanced (ONA - no F−). Specimens were submitted to a 5-day erosion-toothbrushing abrasion cycling. Surface loss (SL) was determined with an optical profilometer. pH and concentration of available fluoride in the slurries were also assessed. Data were statistically analyzed (α = 0.05).
For both substrates, CBW, CNE and EXC had significantly lower SL values than the control. CLW and OMC promoted significantly less dentin wear than the control. All the other groups did not differ significantly from the control. There was a strong negative correlation between SL and concentration of fluoride in the slurries for enamel (r = −0.77) and dentin (r = −0.91), and a strong positive correlation (r = 0.77) between enamel SL and pH.
For both substrates, none of the activated charcoal-based toothpastes resulted in higher SL than brushing with artificial saliva. Only two of the charcoal toothpastes and the reference toothpaste were able to provide further protection against SL.
Activated charcoal-containing toothpastes are becoming popular, despite the absence of evidence supporting their safety for use by individuals with erosive tooth wear. These products did not pose an additional risk for these subjects. However, it would be preferable to use products that exhibits further protective effect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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