Vertical Root Research Articles

Vertical root development of seedlings grown in deep containers: Comparison of five tropical dry forest species in Myanmar

Vertical root development of seedlings grown in deep containers: Comparison of five tropical dry forest species in Myanmar

Evaluation the stress distribution in root canals by 3D finite element analysis after the materials used in reattaching the vertically root fractured fragments.

The aim was to evaluate the effect of stress distribution on vertical, horizontal, and oblique forces on the tooth model after reattaching the fragments of the maxillary incisor with vertical root fracture (VRF) using different materials, by 3D finite element analysis (FEA). Tooth with a root canal, spongious, and cortical bone models were designed. VRF was modeled on a tooth with 4 different re-attachment models: Group 1: dual-cure cement (DC)+fiber reinforced composite (FRC), Group 2: DC+polyethylene fiber, Group 3: DC+glass fiber, and Group 4:DC. 100 N force was applied in 3 different directions. Maximum principal stresses (σmax) of dentin, and re-attachment materials were evaluated on colored images. The highest σmax values ​​were on the repair materials under vertical forces for Groups 1 and 4, respectively; Groups 2 and 3 showed similarity. The highest σmax values in repair materials under horizontal and oblique forces were observed in Group 3 however the lowest σmax values in repair materials under oblique and horizontal forces were observed in Group 1. The stress values ​​on repair materials gradually increased respectively starting from horizontal to vertical. As the elasticity modulus of the repair materials increased, the stress values ​​on root dentin increased. Through all force directions, except vertical forces, lower stress values were observed with FRC. The fracture resistance was bigger when using solely FRC or dual-cure resin cement in comparison to fiber-supported designs. Adding polyethylene fiber to re-restorations decreased stress values ​​compared to glass fiber addition. Therefore, when adding fibers, polyethylene fiber will be advantageous.

Artificial Intelligence in Endodontics: A Scoping Review.

Artificial intelligence (AI) is transforming the diagnostic methods and treatment approaches in the constantly evolving field of endodontics. The current review discusses the recent advancements in AI; with a specific focus on convolutional and artificial neural networks. Apparently, AI models have proved to be highly beneficial in the analysis of root canal anatomy, detecting periapical lesions in early stages as well as providing accurate working-length determination. Moreover, they seem to be effective in predicting the treatment success next to identifying various conditions e.g., dental caries, pulpal inflammation, vertical root fractures, and expression of second opinions for non-surgical root canal treatments. Furthermore, AI has demonstrated an exceptional ability to recognize landmarks and lesions in cone-beam computed tomography scans with consistently high precision rates. While AI has significantly promoted the accuracy and efficiency of endodontic procedures, it is of high importance to continue validating the reliability and practicality of AI for possible widespread integration into daily clinical practice. Additionally, ethical considerations related to patient privacy, data security, and potential bias should be carefully examined to ensure the ethical and responsible implementation of AI in endodontics.

Retrospective Assessment of Endodontically Treated Teeth Replaced by Dental Implants

IntroductionThis study investigated endodontically treated teeth that were replaced by dental implants at the University of North Carolina (UNC) at Chapel Hill School of Dentistry. The primary objective of this study was to determine the reasons leading to the extraction of endodontically treated teeth and their subsequent replacement with dental implants. The secondary objective was to evaluate the proportion of these teeth that, according to experienced endodontists, could have been preserved. MethodsThe UNC-Chapel Hill's dental electronic health records between 2004 and 2019 were probed for implant placement that replaced root canal–treated teeth. Preextraction radiographs and clinical charts were examined to ascertain the primary reason related to the extraction and to compile a profile for each case. In cases in which endodontic failure was the primary reason for extraction, radiographs and clinical findings were evaluated by 2experienced endodontists to assess potential treatment options. ResultsBetween 2004 and 2019, 29.3% (1564 of 5229) of teeth replaced by dental implants at UNC School of Dentistry had undergone root canal treatment, with the mandibular first molar being the most commonly replaced tooth. The leading reasons for extraction were recurrent caries associated with defective restoration (26.6%), fracture of coronal structure (21.5%), vertical root fracture (20.9%), compromised periodontal condition (13.8%), and endodontic failure (2.4%). Two experienced endodontists evaluated extractions due to endodontic failure and concluded that 61.7% of them could have been candidates for endodontic retreatment. ConclusionSubstantial loss of tooth structure was the leading cause of extraction of root canal–treated teeth, followed by vertical root fracture and periodontal disease. Although endodontic failure constituted a minor portion of the reasons for extraction, a considerable number of teeth were extracted due to vertical root fractures following root canal treatment. A significant proportion of the extracted teeth due to endodontic failure could have been considered as potential candidates for endodontic retreatment.

Prevalence of Vertical Root Fractures in a University Endodontics Program versus a Private Endodontics Office.

Vertical root fractures (VRFs) typically have a poor prognosis with an extraction or occasionally root amputation as the preferred treatment. VRFs have been considered an epidemic, motivating changes in the access openings, as well as in the preparation and disinfection protocols of endodontic treatment. Hence, we aimed to evaluate the prevalence of VRFs by tracking cases in both a University Endodontic Program (UEP) and a private endodontics practice (PP). We also evaluated changes in prevalence during COVID-19 along with the alterations in the frequency of cases diagnosed by clinical and radiographic signs which were later confirmed by direct visualization compared to those in which the suspicion was based on clinical and radiographic signs alone. This retrospective study looked at the prevalence of VRF in patient records at UEP and a PP. Data for the pre-COVID-19 and COVID-19 time periods were extracted from patient records and referral letters then compared. Data for suspected and confirmed prevalence were compared. The UEP group included 21,156 patients while the PP group comprised 7,209 patients. The prevalence of VRFs in the former cohort was 1.80%, while 2.62% of the latter cohort exhibited VRFs with a combined total of 2.01%. The combined total prevalence of VRFs pre-COVID-19 was 1.72%, increasing from 2.1% to 3.82% during COVID-19 (p < 0.0001). The same applied to suspected cases for both clinical settings. The increase in confirmed cases between the two periods was statistically significant for the UEP group (p=0.0202) but it was insignificant for the PP group (p=0.0721). The combined prevalence for VRFs was 2.01% for all years denying the claim that VRF is a pandemic phenomenon. COVID-19 period saw almost a double increase in the prevalence of VRF compared to pre-COVID-19 era. This was consequently associated with a significant increase in the number of suspected VRF cases.

Current Progress and Challenges of Using Artificial Intelligence in Clinical Dentistry-A Narrative Review.

The concept of machines learning and acting like humans is what is meant by the phrase "artificial intelligence" (AI). Several branches of dentistry are increasingly relying on artificial intelligence (AI) tools. The literature usually focuses on AI models. These AI models have been used to detect and diagnose a wide range of conditions, including, but not limited to, dental caries, vertical root fractures, apical lesions, diseases of the salivary glands, maxillary sinusitis, maxillofacial cysts, cervical lymph node metastasis, osteoporosis, cancerous lesions, alveolar bone loss, the need for orthodontic extractions or treatments, cephalometric analysis, age and gender determination, and more. The primary contemporary applications of AI in the dental field are in undergraduate teaching and research. Before these methods can be used in everyday dentistry, however, the underlying technology and user interfaces need to be refined.

Varietal Differences in the Root Systems of Rice (Oryza sativa L.) under Drip Irrigation with Plastic Film Mulch

With the escalating water scarcity in agriculture, a novel water-saving technique has emerged: drip irrigation with plastic film mulch (DI). Root function is crucial for sustaining rice production, and understanding its response to DI is essential. However, few studies have evaluated root systems in rice varietals and examined which kind of root system contributes to improving rice grain yield and water productivity in DI. If varietal differences of root reactions for water regimes were made clear, it might be more effective to find suitable varieties for DI and to improve grain yield in the DI system. To fill this knowledge gap, we conducted a two-year field experiment comparing two irrigation systems: continuous flooding (CF) and DI. We analyzed their effectiveness with four rice cultivars, including upland, F1 lowland, animal feed lowland, and lowland cultivars. Vertical root distribution, root bleeding rate, photosynthetic-associated parameters, water productivity, and yield performance were analyzed. In our study, the average grain yield of cultivars in the DI system (6.4 t/ha) was equivalent to those in the CF system (6.6 t/ha). The average water productivity under DI (0.34–0.75 kg m−3) demonstrated significant water-saving potential, saving approximately 35% of the total water supplied, resulting in higher water productivity compared to CF (0.27–0.51 kg m−3). Among the cultivars, the deep root weight of the upland cultivar significantly increased by 51% under DI compared to CF. The deep root ratio was positively correlated with the transpiration rate, grain yield, and water productivity, suggesting its contribution to high transpiration, thus maintaining a high carbon assimilation rate that results in high yield and water productivity. Therefore, deep roots are a notable trait corresponding to high yield under DI, and should be considered for the development of rice growth models for DI and the breeding of aerobic-adapted cultivars.

Threshold response of ecosystem water use efficiency to soil water in an alpine meadow

Ecosystem water use efficiency (WUE) is a coupled index of carbon (gross ecosystem productivity, GEP) and water fluxes (transpiration, Tr or evapotranspiration, ET), reflecting how ecosystem uses water efficiently to increase its carbon uptake. Though ecosystem WUE is generally considered to decrease with increasing precipitation levels, it remains elusive whether and how it nonlinearly responds to extreme water changes. Here, we performed a 5-year precipitation halving experiment in an alpine meadow, combined with extremely interannual precipitation fluctuations, to create a large range of soil water variations. Our results showed that WUETr and WUEET consistently showed a quadratic pattern in response to soil water. Such quadratic patterns were steadily held at different stages of growing seasons, with minor changes in the optimal water thresholds (25.0–28.4 %). Below the water threshold, more soil water stimulated GEP but reduced Tr and ET by lowering soil temperature, resulting in a positive response of ecosystem WUE to soil water. Above the threshold, soil water stimulated GEP less than Tr (ET), leading to a negative response of ecosystem WUE to soil water. However, biological processes, including plant cover and belowground biomass as well as vertical root biomass distribution, had less effect on ecosystem WUE. Overall, this work is among the first to reveal the nonlinearity and optimal water thresholds of ecosystem WUE across a broad range of soil water, suggesting that future extreme precipitation events will more frequently surpass the water threshold and differently change the coupling relationships of carbon and water fluxes in alpine grasslands.

The effect of sealer type and obturation technique on the fracture resistance of endodontically treated roots.

This study evaluated the effect of sealer type with various obturation techniques on the fracture resistance of root filled teeth. Eighty mandibular premolars were collected, and root canals of 70 of them were prepared by Mtwo system up to 40/04. Thirty teeth were obturated using TotalFill BC sealer, and 30 using AH Plus sealer, with one of the obturation techniques (N = 10), namely cold lateral compaction (CLC), warm vertical compaction (WVC), and single cone (SC). Ten teeth were left without obturation as a positive control, and the other 10 teeth were not prepared serving as a negative control. Teeth were stored for 3weeks, and the crowns were separated and the roots were subjected to fracture test using a universal testing machine. Data was analyzed by ANOVA followed by Tukey's test. Fracture resistance of the TotalFill groups was significantly higher than the AH Plus groups in each obturation technique, and SC had the highest fracture resistance regardless of sealer used (P < 0.05). Obturation of the root canal by TotaFill BC sealer increased the calcium/phosphorous ratio in the dentin of the root. Obturation with TotalFill BC sealer improved the fracture resistance of the roots more than AH Plus sealer, and obturation with SC resulted in higher fracture resistance than CLC and WVC. Obturation of the root canal with Bioceramic sealer with single cone obturation technique could reduce the incidence of vertical root fracture.

Belowground competition and niche partitioning between the Babassu palm and Urochloa grass in eastern Amazonian pastures

AbstractMuch of deforested Amazonia is dominated by pastures planted with exotic Urochloa (syn Brachiaria) grass, containing interspersed, ruderal Babassu palm (Attalea speciosa). This two‐species system offers the opportunity to investigate how two very competitive species interact. We investigated three monospecific Urochloa pastures containing dispersed Babassu palm clusters in the eastern periphery of Amazonia. We mapped 0‐ to 50‐cm Babassu and Urochloa root profiles at three distances representing contrasting relative dominance: “within clusters” (0.4–0.6 m from adult palm, Babassu‐dominated), “close” (2.5–4.0 m), and “far” (&gt;8.0–10.0 m, Urochloa‐dominated). Total Babassu root share count was 76.0% within Babassu clusters, as opposed to Urochloa root share count (80.0%) far from clusters, confirming our experimental dominance gradient. Babassu and Urochloa root diameter composition differed strongly, whereas 44.6% of all Babassu roots were mid‐diameter or coarse; 83.0% of all Urochloa roots were fine graminoid. Vertical root profiles likewise differed: Babassu coarse and mid‐diameter roots concentrated within clusters at 20–50 cm depth, well protected against disturbance, though Babassu mid‐diameter roots did extend up to 10 m, indicating active foraging at long distances. By contrast, Urochloa mid‐diameter and coarse roots concentrated in the topsoil (70.4% in top 20 cm). Notably, 45.0% of all Urochloa fine roots but only 29.3% of deeper rooting Babassu concentrated in the top 0–10 cm. Both Urochloa mid‐diameter (R = 0.49) and fine roots (R = 0.40) correlated positively with Urochloa aboveground biomass. Fine‐root fine‐scale variability was high, with high‐density hotspots of both species in the topsoil. Babassu vertical root profiles were unaffected by the degree of interspecific competitive confrontation, whereas Urochloa fine roots were significantly shallower within than outside of Babassu clusters. Though differing Babassu and Urochloa vertical root profiles do support the notion of niche expansion caused by Babassu clusters within the vast Urochloa pastures throughout Amazonia, we also find a strong horizontal and vertical niche overlap with no indication of fine‐scale root segregation, indicating direct competition between both species, possibly in a dynamic state of “mutual invasability.” In practical terms, our findings call for the diversification of Amazonian pastures beyond this two‐species system in order to increase productivity and ecological efficiency.

Rest–grazing before soil thawing alters the below‐ground distribution and extent of rooting in Carex subalpine meadows

AbstractLivestock activities impact plant rhizomes and roots in the topsoil, particularly in the early stages of spring for a Carex subalpine meadow. Rest–grazing during critical periods can prevent harm to these roots and rhizomes caused by livestock, thereby enhancing the ecological performance of grasslands. In accordance with soil thawing and plant re‐greening, we designated five rest–grazing periods during the spring in a Carex subalpine meadows. The findings demonstrate that the topsoil of 0–10 cm, largely consisting of Carex roots, housed over 70% of root volume and root mass. After the plant had regained its greenery for a certain duration, rest–grazing resulted in higher vertical root length distribution index. With earlier rest–grazing, root growth in deeper soil was promoted, consequently transporting more organic material to the deeper soil. Deferred rest–grazing time has the potential to enhance lateral rooting extent, root resistance to vertical uprooting, and root accumulation in topsoil. It follows that increased root accumulation in the topsoil leads to greater loss of soil nutrients and carbon. Consequently, we recommend rest–grazing prior to soil thawing for Carex subalpine meadows, which encourages Carex root growth and fosters greater biomass accumulation in deeper soils. Avoiding “running for the green” and “trampling tillage” has a positive effect on both productivity and long‐term soil nutrients and carbon pool management in pastures.

In vitro evaluation of the impact of a bioceramic root canal sealer on the mechanical properties of tooth roots

Bacground/purposeEndodontically treated teeth are more prone to vertical root fracture with the mechanical property changes to some extent during root canal treatment. This study aimed to investigate the effects of a bioceramic sealer on the mechanical properties of tooth roots. Materials and methodsDentin discs were dried by two different methods (ethanol drying and paper points drying) and then filled with a BC sealer named iRoot SP. SEM and EDS were used to analyze the newly formed minerals in dentin tubules. Elastic modulus and hardness of the secondary dentin in areas proximal to the primary dentin (PD-SD) and areas proximal to canal or iRoot SP (SD-C/SD-iRoot SP) were measured using nanoindentation technique. The compressive strength of roots filled with iRoot SP were tested by compressive loading test. Results(1) Penetration and mineralization: Paper points drying was more conducive to iRoot SP adhesion, spreading and penetration into the dentin tubules than 95% ethanol drying. (2) Micromechanical properties: After filling root canal with iRoot SP, the elastic modulus and hardness of SD-iRoot SP were higher than those of PD-SD (P = 0.001 and P = 0.000). (3) Fracture resistance: The compressive strength of the roots filled with iRoot SP was not significantly different from that of the roots unprepared and unfilled (P = 0.957), but was higher than that of the roots prepared and unfilled (P = 0.009). ConclusionExcessive drying (95% ethanol drying method) is not conducive to the penetration and mineralization of the BC sealer iRoot SP into dentin tubules. The good bioactivity of iRoot SP was responsible for increasing the elastic modulus and hardness of dentin, which strengthened the prepared roots.

Endodontic Microsurgery for a Mandibular First Molar With a Large Lateral Canal in Mesial Root: A Case Report

Introduction: The lateral canal that occurs in the mesial root of the mandibular first molar is relatively rare. Herein we reported a rare case about a large lateral canal located in the middle of the mesial root of mandibular molar. Case report: A 38-year-old woman presented with symptomatic apical periodontitis and J-shaped bone defect similar to vertical root fracture on the mesial root of tooth #30. Endodontic microsurgery was chosen to make a clear diagnosis and treatment. The procedure was carried out with apicoectomy, root-end and lateral canal preparation, and retrograde filling. At the 1-year follow-up, clinical examination and the radiograph showed complete healing. Discussion: The untreated mesiobuccal root canal with large lateral canal was found to be the cause of the J-shaped bone defect.

Findings, Identification and Etiology of Vertical Root Fractures

Findings, Identification and Etiology of Vertical Root Fractures

Standardization of vertical root resection during socket shield technique in immediate implant placement

Objectives. The aim of the present study was to standardize an accurate and significant technique of root separation during socket shield technique. Patients and methods. Two phases of the study were conducted. In vitro study was performed on 20 extracted single-rooted anterior teeth. The second phase was clinical application of the new technique on 10 patients seeking to restore their badly decayed anterior teeth in the esthetic area with immediate implant placement utilizing the socket shield technique. Decoronation was done. The root canal was mechanically enlarged by means of manual assorted files. Canals were further enlarged with Gates Glidden drills. Peeso Reamer drills were used till the root was entirely separated into two parts (buccal &amp; palatal). The palatal root was cautiously removed when the labial and palatal root halves were sufficiently separated. In case the root to be removed was endodontically treated, Gutta-percha was mechanically removed using Gates Glidden, &amp; Gutta-percha solvent to remove the coronal and apical parts. Outcomes. Using manual endodontic K-files, Gates Glidden burs, and Peeso Reamer’s drills in separating the single-rooted teeth into two halves is a reproducible, and reliable procedure during socket shield technique. Conclusions. This technique prevents possible complications of root sectioning during socket shield technique with immediate implant placement. It preserves surrounding soft tissue structures, and labial shield during shield preparations, maintains the integrity of the labial plate of bone during extraction. Additionally, it offers total root apex removal by entirely separating the palatal portion from the labial shield.

Outcome after Partial Pulpotomy: Long-term Results of the Prospective Clinical MMP-9 Study.

While the objective of partial pulpotomy is to preserve the vitality and function of the pulp tissue, the preopera-tive pulp status is the main prognostic factor for its success. To date, however, there is little data on long-term success rates. Therefore, the aim of this prospective pilot study was to assess the long-term outcome of partial pulpotomy in per-manent teeth after carious pulp exposure without signs or symptoms of irreversible pulpitis, verified clinically, radio-graphically, and via MMP-9 levels. Patients in whom permanent teeth with extremely deep carious lesions were diagnosed as com-pletely asymptomatic (n = 8) or with signs of reversible pulpitis (n = 10) underwent non-selective caries removal followed by a blood test to assess the level of MMP-9. The teeth were thereafter partially pulpotomised, MTA-capped, and immedi-ately restored with composite resin. Follow-up examinations were performed by endodontically experienced examiners focusing on clinical and radiographic assessment. One patient could not be contacted and was lost to follow-up. Overall, the follow-up period ranged from 2-8 years (mean = 4.4 years). The majority of teeth remained functional and without pathology; one tooth was classified as having failed because of a vertical root fracture. There was no statistically significant difference in the groups' success rate (p = 0.3). The estimated overall survival rate was 94.1% (95% CI: 0.84-1.00) after 4 years according to the Kaplan-Meier method. Pulp vitality in permanent teeth can be preserved with high success rates by means of partial pulpotomy after carious pulp exposure in asymptomatic teeth or in teeth with reversible pulpitis.

Rootstocks Alter the Seasonal Dynamics and Vertical Distribution of New Root Growth of Vitis vinifera cv. Shiraz grapevines

Minirhizotron tubes were installed to monitor root growth dynamics of mature Shiraz grapevines in a rootstock trial established in the hot climate Riverina region of New South Wales, Australia. The vertical root distribution and seasonal root growth dynamics of Shiraz on own-roots and Shiraz grafted on the rootstocks Ramsey, 140 Ruggeri and Schwarzmann was studied for five seasons across a seven-year period to a depth of 60 cm. New root production was significantly influenced by genotype, soil depth, season, growth stage and year. Soil moisture and soil temperature were monitored at 10, 30 and 60 cm in the last two seasons. Soil moisture at 30 cm and soil temperature at all three depths were significant predictors of root growth. New root numbers were significantly higher in 140 Ruggeri than the other rootstocks. To the depth studied, 140 Ruggeri roots were evenly distributed from the topsoil down, whereas the majority of roots of Schwarzmann and Shiraz were located at intermediate depths in the 10–40 cm ad 20–40 cm zones respectively, while Ramsey roots were found at 20 cm or below. Depending on genotype, root growth occurred across several phenological stages but tended to peak at flowering. In some years we observed root growth in early and late winter at rates exceeding that of autumn, and this was associated with warmer temperatures during this period. In general, the seasonal dynamics of root growth attributes were found to be influenced by abiotic factors, but mainly determined by genotype. The insights gained from this study can help us better understand the interplay between rootstock, environment, and management, and predict how different rootstock genotypes may perform under changing climatic conditions.

Antigravitropic PIN polarization maintains non-vertical growth in lateral roots

Lateral roots are typically maintained at non-vertical angles with respect to gravity. These gravitropic setpoint angles are intriguing because their maintenance requires that roots are able to effect growth response both with and against the gravity vector, a phenomenon previously attributed to gravitropism acting against an antigravitropic offset mechanism. Here we show how the components mediating gravitropism in the vertical primary root—PINs and phosphatases acting upon them—are reconfigured in their regulation such that lateral root growth at a range of angles can be maintained. We show that the ability of Arabidopsis lateral roots to bend both downward and upward requires the generation of auxin asymmetries and is driven by angle-dependent variation in downward gravitropic auxin flux acting against angle-independent upward, antigravitropic flux. Further, we demonstrate a symmetry in auxin distribution in lateral roots at gravitropic setpoint angle that can be traced back to a net, balanced polarization of PIN3 and PIN7 auxin transporters in the columella. These auxin fluxes are shifted by altering PIN protein phosphoregulation in the columella, either by introducing PIN3 phosphovariant versions or via manipulation of levels of the phosphatase subunit PP2A/RCN1. Finally, we show that auxin, in addition to driving lateral root directional growth, acts within the lateral root columella to induce more vertical growth by increasing RCN1 levels, causing a downward shift in PIN3 localization, thereby diminishing the magnitude of the upward, antigravitropic auxin flux.

Comparison of Dentinal Defects Formation in Straight, Moderate and Severely Curved Canals by Three Distinctive Nickel Titanium Instruments: An in vitro Study.

It is stated that engine-driven instruments might cause dentinal defects during root canal preparation. These defects might spread and progress into greater fractures or vertical root fracture. This study aimed to compare the incidence of dentinal defects that might arise all through preparation of root canals, using One Shape, RaCe, and WaveOne systems in canals with a curvature (0-20°) and (20-40°). In this in vitro study, 150 mandibular first molars were enrolled. Based on the degree of curvature in the mesial roots, the samples were divided into two groups (n=75) of straight and moderately curved canals (0-20º), and severely curved canals (20-40°). Then each group was randomly divided into four sub-groups. In subgroups 1 to 3 from each group, canals were prepared using WaveOne, One Shape, and RaCe. Then all roots were sectioned at 3, 6 and 9-mm distances from the apex. The slices were evaluated using stereomicroscope at 12× magnification. The data were analyzed using the Chi-square and Fisher's exact tests and the level of significance was set at 0.05. Fracture and other defects were not found in the control groups. In canals with curvature (0-20°), WaveOne caused the maximum dentinal defects and RaCe produced the least. Moreover, in canals with curvature (20-40°), One Shape caused the maximum dentinal defects while WaveOne and RaCe caused equal dentinal defects approximately. There was a statistically significant relationship between the performance of RaCe and One Shape in canals with curvature (0-20º) and (20-40º), (pValue< 0.05) while no statistically significant difference was observed in connection to the performance of WaveOne (p> 0.05).

Prevalence of and Factors Associated With Vertical Root Fracture in a Japanese Population: An Observational Study on Teeth With Isolated Periodontal Probing Depth

IntroductionPrevious studies on the prevalence of vertical root fractures (VRFs) were based on extracted teeth, or teeth referred for apical surgery. This study examined teeth with an isolated periodontal probing depth (PD) as an indicator of VRF. The primary aim of this study was to investigate the prevalence of vertical root fracture (VRF) and non-VRF among teeth with an isolated probing depth (PD) ≥ 5 mm. The secondary aim was to assess factors associated with VRF by comparing the teeth with and without VRF in the Japanese population. MethodsA total of 288 teeth with an isolated PD ≥ 5 mm were grouped pathologically into 8 groups comprising VRF and non-VRF conditions. A descriptive analysis for age, sex, tooth type, endodontically treated teeth (ETT) versus non-ETT, proximal contacts, PD (depth), PD (broadness and location), restoration type, and presence of a post was performed. Moreover, the associations between these factors and VRFs were investigated using the Chi-square test. ResultsThe prevalence of VRF was 32%. Lower first molars were the most common tooth type in both VRF (31.5%) and non-VRF groups (29.7%), while premolars were exclusively frequent in VRF (30.2%) and not frequent in non-VRF (7.8%). Narrow buccolingual PD was common in VRF (78.1%) whereas wide PD was frequent in non-VRF (67.1%). ETT, narrow buccolingual PD, tooth type (premolars), restoration type (crown), and the presence of a post showed significant associations with VRF (P ≤ .001). ConclusionsVRFs may be more prevalent in ETT among the Japanese. Careful assessment is necessary to differentiate VRFs from other conditions when the lower first molars show an isolated PD ≥ 5 mm. When an endodontically treated premolar with a post shows a narrow buccolingual PD, the probability of a VRF may be greater than in other tooth types.