Clinical and radiographic features of external cervical resorption - An observational study.

AIM: To determine the prevalence of symptoms, clinical signs and radiographic presentation of external cervical resorption (ECR). METHODOLOGY: This study involved 215 ECR lesions in 194 patients referred to the Endodontic postgraduate Unit at King's College London or Specialist Endodontic practice (London, UK). The clinical and radiographic findings (periapical [PA] and cone beam computed tomography [CBCT]) were readily accessible for evaluation. A checklist was used for data collection. Inferential analysis was carried out to determine if there was any potential association between type and location of tooth in the jaw as well as sex, age of the patient and ECR presentation and radiographic feature. RESULTS: Eighty-eight patients (94 teeth) were female and 106 patients were male (121 teeth), the mean age (±SD) was 41.5 (±17.7) years. Fifteen patients (7.7%) had more than one ECR lesion. The most affected teeth were maxillary central incisors (21.4% [46 teeth]) and mandibular first molars (10.2% [22 teeth]). ECR was most commonly detected as an incidental radiographic finding in 58.1% [125 teeth] of the cases. ECR presented with symptoms of pulpal/periapical disease in 23.3% [n = 50] and clinical signs (e.g. pink spot, cavitation) in 16.7% [36 teeth] of the cases. Clinical signs such as cavitation (14%), pink spot (5.1%) and discolouration (2.8%) were uncommon, but their incidence increased up to 24.7% when combined with other clinical findings. ECR was detected in the resorptive and reparative phases in 70.2% and 29.8% of the cases respectively. CONCLUSION: ECR appears to be quiescent in nature, the majority being asymptomatic and diagnosed incidentally from PA or CBCT. When assessed with the Patel classification, most lesions were minimal to moderate in relation to their height (1 or 2) and circumferential spread (A or B). However, the majority of ECRs were in (close) proximity to the pulp. Symptoms and clinical signs were associated with (probable) pulp involvement rather than the height and circumferential spread of the lesion. Clinical signs were more frequently associated when ECR affected multiple surfaces.

ESE position statement on root resorption.

This Position Statement on root resorption represents the consensus of an expert committee convened by the European Society of Endodontology (ESE). The statement is based on current clinical and scientific evidence as well as the expertise of the committee. The aim is to provide clinicians with authoritative information on the aetiology, histopathology, clinical presentation and recommendations for the management of root resorption. It is the intention of the committee to update this position statement at appropriate intervals as further evidence emerges.

A clinical approach strategy for the diagnosis, treatment and evaluation of external cervical resorption.

AIM: To propose a clinical approach strategy on the diagnosis, treatment and evaluation of external cervical tooth resorption (ECR) cases. To investigate and discuss the outcome of this approach. METHODOLOGY: A clinical approach strategy on ECR was developed based on a retrospective observation study of 542 teeth. Forty-seven teeth were excluded due to lack of clinical/radiographical information, and 182 were immediately extracted. This approach had three steps: diagnosis, treatment planning and evaluation. During diagnosis, the medical, dental history and clinical/radiographical characteristics were evaluated. Depending on the resorption extent, ECR cases were categorized into four classes according to Heithersay's classification. During treatment planning, a treatment decision flowchart was prepared based on four main decisive criteria: probing feasibility, pain, location and extent of resorption (class), and existence of bone-like tissue. Three treatment options were applied: (a) extraction, (b) monitoring or (c) conservative treatment by external, internal or combination of internal-external treatments. During evaluation, assessment of ECR progression, tooth survival and other factors like aesthetics and periodontal attachment were performed. Descriptive statistical analysis of the outcome for up to 10 years (for the overall clinical approach and for each individual treatment decision), was carried out with OriginLabs OriginPro 9 and Microsoft Excel 365. RESULTS: A three-step strategy was developed on how to deal with ECR cases. Indicative examples of each treatment decision were presented and discussed. The overall survival rate of this strategy was 84.6% (3 years), 70.3% (5 years), 42.7% (8 years) and 28.6% (10 years). Higher survival rate was observed for external treatment decision than for internal. The success of each treatment decision depended on the extent of the resorption (class). The success of a treatment decision should be based on the long-term outcome, as a different evolution can be observed with time. CONCLUSIONS: A clinical approach strategy was introduced on ECR pathosis. This strategy was not solely based on ECR class, as other important decisive criteria were considered. This step-wise approach, has a 70.3% survival rate with a mean of 5 years. This work will hopefully provide an incentive for a broader collaboration, to potentially establish a universally accepted ECR treatment strategy.

Dynamic navigation: a laboratory study on the accuracy and potential use of guided root canal treatment.

AIM: To evaluate 3D accuracy and outcome of a dynamic navigation method for guided root canal treatment of severe pulp canal obliteration (PCO) in 3D printed jaws. METHODOLOGY: Three operators with different levels of experience in Endodontics performed navigated access cavities, using the Navident system (ClaroNav), in two sets (maxillary and mandibular) of 3D-printed jaw models with teeth presenting severe PCO. Models were mounted on a phantom to mimic a real clinical situation. After treatment, a postoperative high resolution Cone-Beam Computer Tomography (CBCT) scan (NewTom) was taken for each model and registered to the preoperative model. All access cavities were then segmented using 3-Matic Medical software 15.0 (Materialise). Length and volume of each access cavity were measured, and a comparison was done by measuring the distance deviation in mm at the coronal entry point, apical point, vertical deviation, total deviation and angular deviation of the access cavity in comparison with the virtual planning. Additionally, all access cavities were scouted with a size 10 K-file and inspected on the CBCT to confirm that the canal was located. Descriptive statistics for each parameter were performed. Normality of the data was assessed; data were transformed if needed to make it normally distributed. One-way analysis of variance (anova) was applied to assess differences between parameters for tooth type, jaw, and operators and corrected for simultaneous hypothesis testing according to Tukey. Significance level was set at .05. RESULTS: After training with the system (28 cavities per operator), a total of 132 teeth and 168 access cavities (56 per operator) were prepared. All operators located a total of 156 canals, obtaining an overall success of 93% without a difference between operator experience (p > .05). The mean deviation at the apical point was 0.63 mm (SD 0.35) and was significantly lower in anterior teeth in comparison with molars (p < .05). The mean angular deviation from the planning was 2.81° (SD 1.53). CONCLUSION: Dynamic navigation was an accurate approach for root canal treatment in teeth with severely calcified canals. However, the technique has a learning curve and requires extensive training prior to its use clinically.

Multi-modular bone healing assessment in a randomized controlled clinical trial of root-end surgery with the use of leukocyte- and platelet-rich fibrin and an occlusive membrane.

OBJECTIVES: The aim of this study was to assess in a multi-modular manner the bone healing 1 year post root-end surgery (RES) with leukocyte- and platelet-rich fibrin (LPRF) and Bio-Gide® (BG; Geistlich Pharma North America, Inc., Princeton, USA) as an occlusive membrane. MATERIALS AND METHODS: A randomized controlled clinical trial (RCT) of RES +/- LPRF and +/- BG was performed. The follow-up until 1 year post RES was performed by means of ultrasound imaging (UI), periapical radiographs (PR), and cone-beam computed tomography (CBCT). RESULTS: From the 50 included patients, 6 dropped-out during follow-up. For the 44 assessed patients (34 with UI and 42 with PR and CBCT), there was no evidence (p > 0.05) for an effect of LRPF, neither on UI measurements nor on CBCT assessments. On the contrary, there was an indication for a better outcome with BG. UI presented significant shorter healing time for the bony crypt surface (p = 0.014) and cortical opening (p = 0.006) for the groups with BG. The qualitative CBCT assessment for the combined scores of the apical area and cortical plane was significantly higher for BG (p = 0.01 and 0.02). The quantitative CBCT measurement for bone healing after 1 year was lower with BG (p = 0.019), as well as the percentage of non-zero values (p = 0.026), irrespective of the preoperative lesion size and type. Furthermore, UI seemed to be safer for frequent follow-up during the early postoperative stage (0-3 months), whereas CBCT gave more accurate results 1 year post RES. Amongst the assessors, the qualitative PR analysis was inconsistent for a favorable outcome 1 year post RES with LPRF (p = 0.11 and p = 0.023), but consistent for BG (p = 0.024 and p = 0.023). CONCLUSIONS: There was no evidence for improvement of bone healing when RES was applied with LPRF in comparison with RES without LPRF. However, RES with BG gave evidence for a better outcome than RES without BG. CLINICAL RELEVANCE: The addition of an occlusive membrane rather than an autologous platelet concentrate improved bone regeneration 1 year post RES significantly, irrespective of the assessment device applied. The accuracy of PR assessment is questionable.

Secondary caries: prevalence, characteristics, and approach.

OBJECTIVES: The objectives of this cross-sectional survey were to determine the prevalence of secondary caries (SC) in general population, to identify patient- and material-related factors which may affect the prevalence, and to describe some clinical characteristics of SC lesions. MATERIALS AND METHODS: A total of 4036 restorations in 450 patients, who visited the university dental clinic for a regular (half) yearly checkup, were examined clinically (and radiographically) for the presence of SC. Clinical characteristics of the detected SC lesions (size, activity, and location) and the planned treatment were recorded. In addition, patients' caries-risk status was assessed according to the modified "cariogram" model. RESULTS: In total, 146 restorations were diagnosed with SC, which gives an overall prevalence of 3.6%. Restorative material, restoration class, patient's caries risk, and smoking habits were shown to be important factors, as SC prevalence was significantly higher with composites, class II restorations, high-caries-risk patients, and smokers. Restorations' gingival margins were most frequently affected by SC. The largest number of restorations with SC (72%) was scheduled for the replacement. CONCLUSIONS: Prevalence of SC was higher with composite than with amalgam restorations, irrespective of the patient's caries-risk status. Gingival margins of class II, including MOD restorations, seem to be the place of less resistance to SC development. Management of SC seems to place a considerable burden on the health care workforce and expenditure. CLINICAL RELEVANCE: Secondary caries (SC) is considered to be the main cause of dental restoration failure and one of the biggest clinical challenges related to dental composites. Nevertheless, its prevalence in daily practice is still not clear, which impedes an accurate estimation of its impact on health care costs.

Root-end surgery with leucocyte- and platelet-rich fibrin and an occlusive membrane: a randomized controlled clinical trial on patients' quality of life.

OBJECTIVES: The aim of this study was to investigate the impact of the adjunct of leukocyte- and platelet-rich fibrin (LPRF) to root-end surgery (RES) on the patients' quality of life during the first week post RES. MATERIALS AND METHODS: Patients in need of RES were recruited for an open randomized controlled clinical trial (RCT) with a 2 × 2 factorial design. They were randomly allocated to the test (+LPRF) and control (-LPRF) group. Each group was subsequently divided into two strata: with or without an occlusive membrane (Bio-Gide®, Geistlich Biomaterials, Switzerland; BG). After RES, the patients completed daily for 1 week a visual analog pain scale (VAS) and a 5-point Likert-type scale questionnaire concerning activity impairment, occurrence of symptoms, and medication use. RESULTS: Fifty patients were included, equally divided between the test and control group. Only one patient in the "-LPRF+BG-group" had to take additional antibiotics due to a persistent jaw swelling. There was no evidence (p ≤ 0.05) for a difference between the test and control group in VAS, occurrence of pain symptoms, impairment of daily activities, and medication use, over the 7 days and daily during the 7 days post RES. CONCLUSIONS: There was no statistical significant evidence for improvement of patients' quality of life during the first week post RES with LPRF in comparison with RES without LPRF. CLINICAL RELEVANCE: Although LPRF seems to be an inexpensive and autologous agent to reduce pain and swelling post RES, this RCT does not provide a statistical significant evidence for that.

Regenerative potential of leucocyte- and platelet-rich fibrin. Part A: intra-bony defects, furcation defects and periodontal plastic surgery. A systematic review and meta-analysis.

AIM: To analyse the regenerative potential of leucocyte- and platelet-rich fibrin (L-PRF) during periodontal surgery. MATERIALS AND METHODS: An electronic and hand search were conducted in three databases. Only randomized clinical trials were selected and no follow-up limitation was applied. Pocket depth (PD), clinical attachment level (CAL), bone fill, keratinized tissue width (KTW), recession reduction and root coverage (%) were considered as outcome. When possible, meta-analysis was performed. RESULTS: Twenty-four articles fulfilled the inclusion and exclusion criteria. Three subgroups were created: intra-bony defects (IBDs), furcation defects and periodontal plastic surgery. Meta-analysis was performed in all the subgroups. Significant PD reduction (1.1 ± 0.5 mm, p < 0.001), CAL gain (1.2 ± 0.6 mm, p < 0.001) and bone fill (1.7 ± 0.7 mm, p < 0.001) were found when comparing L-PRF to open flap debridement (OFD) in IBDs. For furcation defects, significant PD reduction (1.9 ± 1.5 mm, p = 0.01), CAL gain (1.3 ± 0.4 mm, p < 0.001) and bone fill (1.5 ± 0.3 mm, p < 0.001) were reported when comparing L-PRF to OFD. When L-PRF was compared to a connective tissue graft, similar outcomes were recorded for PD reduction (0.2 ± 0.3 mm, p > 0.05), CAL gain (0.2 ± 0.5 mm, p > 0.05), KTW (0.3 ± 0.4 mm, p > 0.05) and recession reduction (0.2 ± 0.3 mm, p > 0.05). CONCLUSIONS: L-PRF enhances periodontal wound healing.

Regenerative potential of leucocyte- and platelet-rich fibrin. Part B: sinus floor elevation, alveolar ridge preservation and implant therapy. A systematic review.

AIM: To analyse the effect of leucocyte- and platelet-rich fibrin (L-PRF) on bone regeneration procedures and osseointegration. MATERIALS AND METHODS: An electronic and hand search was conducted in three databases (MEDLINE, EMBASE and Cochrane). Only randomized clinical trials, written in English where L-PRF was applied in bone regeneration and implant procedures, were selected. No follow-up restrictions were applied. RESULTS: A total of 14 articles were included and processed. Three subgroups were created depending on the application: sinus floor elevation (SFE), alveolar ridge preservation and implant therapy. In SFE, for a lateral window as well as for the trans-alveolar technique, histologically faster bone healing was reported when L-PRF was added to most common xenografts. L-PRF alone improved the preservation of the alveolar width, resulting in less buccal bone resorption compared to natural healing. In implant therapy, better implant stability over time and less marginal bone loss were observed when L-PRF was applied. Meta-analyses could not be performed due to the heterogeneity of the data. CONCLUSIONS: Despite the lack of strong evidence found in this systematic review, L-PRF might have a positive effect on bone regeneration and osseointegration.

The impact of autologous platelet concentrates on endodontic healing: a systematic review.

The current literature was reviewed to determine the impact of autologous platelet concentrates (APCs) on endodontic healing. All types of clinical study designs concerning any kind of endodontic treatment involving the application of APCs were included. Two independent reviewers searched three databases (PubMed, Embase, and Cochrane Library) for studies, complemented by hand search, until 16/1/2016. From the 423 identified records, 48 articles met the inclusion criteria. Selected randomized controlled clinical trials (RCTs) underwent Cochrane Collaboration's risk-of-bias assessment and data extraction. Only two RCTs showed low risk of bias. There was considerable heterogeneity between the RCTs with regard to the type of therapy, type of APCs, assessment method, and study quality, and therefore the data could not be analyzed quantitatively. The included case reports/series and non-randomized comparative studies underwent qualitative analysis with the revised Methodological Index for Non-Randomized Studies (MINORS) and data extraction. The two comparative non-randomized studies scored qualitatively high, though the MINORS-scores of the case series and reports were dispersed. APCs were involved in five endodontic treatment modalities, namely apexification, regenerative endodontic procedures, pulpotomy, apical surgery, and treatment of endo-perio/perio-endo lesions. APCs seem to accelerate postoperative bone healing, augment the patients' postoperative quality of life, aid further root development, and support maintenance/regaining of pulp vitality. No adverse events were reported. APCs in endodontic treatments seem to contribute to the healing of soft and hard tissues, though there is a lack of long-term high quality clinical trials and standardized treatment protocols.

Regenerative endodontic procedure of an infected immature permanent human tooth: an immunohistological study.

OBJECTIVES: An immunohistological study of an infected immature permanent human tooth after a regenerative endodontic procedure (REP) was conducted in order to determine the histologic outcome of this procedure. Besides observed signs of angiogenesis and neurogenesis, repair and/or regeneration of the pulp-dentin complex was also investigated. MATERIALS AND METHODS: A REP was performed on tooth 45 of a 10-year-old girl. Eleven months post-treatment, the tooth had to be removed for orthodontic reasons. The following investigations were performed: immunohistology and radiographic quantification of root development. After hematoxylin-eosin (HE) staining, the following immunomarkers were selected: neurofilament (NF), pan cytokeratin (PK), osteocalcin (OC), and CD34. RESULTS: The REP resulted in clinical and radiographic healing of the periradicular lesion and quantifiable root development. The HE staining matches with the medical imaging post-REP: underneath the mineral trioxide aggregate a calcified bridge with cell inclusions, connective pulp-like tissue (PLT) with blood vessels, osteodentin against the root canal walls, on the root surface cementum (Ce), and periodontal ligament (PDL). The PDL was PK(+). The blood vessels in the PLT and PDL were CD34(+). The Ce, osteodentin, and stromal cells in the PLT were OC(+). The neurovascular bundles in the PLT were NF(+). CONCLUSIONS: Immunohistologically, REP of this infected immature permanent tooth resulted in an intracanalar connective tissue with a regulated physiology, but not pulp tissue. CLINICAL RELEVANCE: REP of an immature permanent infected tooth may heal the periapical infection and may result in a combination of regeneration and repair of the pulp-dentin complex.

How does nano-focus computed tomography impact the quantification of debris within the root canal system?

The aim of this study was to compare the quantification of hard-tissue debris by using micro-computed tomography (micro-CT) and nano-focus computed tomography (nano-CT) after root canal instrumentation. Ten mandibular molars containing an isthmus in the mesial root were scanned in a SkyScan 1172 micro-CT device with a voxel size of 12.8 µm and in a NanoTom nano-CT device with 5.5 µm. The mesial root canals were irrigated with 5 mL of saline solution at the orifice level, instrumented with Reciproc R25 files and a second scanning was performed by micro-CT and nano-CT devices for post-instrumentation images. DataViewer software was used for registering the pre- and post-operative micro-CT and nano-CT images. The root canal and the debris were segmented for quantitative analysis of the volume of the canal and volume of debris using CTAn software. Statistical analysis was performed using the T test for comparison between volume of the canal after instrumentation and volume of debris in both image modalities. The level of significance was set at p < 0.05. Nano-CT images showed higher values of debris when compared with micro-CT (p < 0.05) after root canal instrumentation. No difference was observed between the volume of the root canal after instrumentation in the two imaging methods used (p > 0.05). Nano-CT technology can be recommended as a more precise method for quantitative analysis of hard-tissue debris. Moreover, in Endodontic research it is a promising method, as it is capable of providing higher spatial and contrast resolution, faster scanning and higher image quality.

A 13-year clinical evaluation of two three-step etch-and-rinse adhesives in non-carious class-V lesions.

This 13-year randomized clinical trial compared the clinical effectiveness of two three-step etch-and-rinse adhesives in combination with a hybrid, stiffer composite versus a micro-filled, more flexible composite. The influence of composite stiffness on the clinical performance of one of the adhesives was assessed as well. One hundred and forty-two non-carious cervical lesions were restored with composites with contrasting stiffness. Seventy-one patients randomly received two cervical restorations placed following two out of three adhesive procedures: (1) the three-step etch-and-rinse adhesive Permaquick applied with the stiff micro-hybrid composite Amelogen Hybrid (PMQ-H, Ultradent), (2) Permaquick applied with the more flexible micro-filled Amelogen Microfill (PMQ-M, Ultradent), or (3) the "gold-standard" three-step etch-and-rinse adhesive Optibond FL applied with the micro-hybrid composite Prodigy (OFL-P, Kerr). The restorations were evaluated after 6 months, 1, 2, 3, 5, 7, and 13 years of clinical service regarding their retention, marginal integrity and discoloration, caries occurrence, preservation of tooth vitality, and post-operative sensitivity. Retention loss, severe marginal defects, and/or discoloration that needed intervention (repair or replacement) and the occurrence of caries were considered as clinical failures. The recall rate at 13 years was 77%. Bond degradation after 13 years was mainly characterized by a further increase in the presence of small but clinically acceptable marginal defects and superficial marginal discoloration. Twelve percent of the OFL-P restorations were clinically unacceptable. In the PMQ group, 22% of the PMQ-M restorations and 26% of the PMQ-H restorations needed repair or replacement. Regarding the clinical failure rate, Optibond FL scored significantly better than Permaquick (McNemar; p = 0.015). No statistically significant differences were found between the micro-filled and the hybrid composite for each of the parameters evaluated (McNemar, p > 0.05). After 13 years of clinical functioning, the clinical effectiveness of the three adhesive/composite combinations remained highly acceptable.

Nanohybrid and microfilled hybrid versus conventional hybrid composite restorations: 5-year clinical wear performance.

UNLABELLED: The 5-year findings of a randomized clinical trial testing the null hypothesis that there are no differences between the clinical-wear performances of nano-, microfilled-, and conventional hybrids placed in class I and class II cavities are reported. Effects of subject-, operator-, and restoration-related variables on wear were assessed. Sixteen Tetric-C, 17 Tetric-EC, and 16 Gradia-DP restorations were placed in human molars and recalled at baseline, 6 months and at yearly intervals. The gypsum replicas at each recall were scanned (3D laser scanning), epoxy resin replicas were observed under scanning electron microscope and linear mixed models were used to study the influence of different variables on wear. The generalized vertical wear rate/month were (1.4 µm Tetric-C and Tetric-EC; 1.8 µm Gradia-DP) and volume wear rate/month were (0.017 mm(3) Tetric-EC; 0.018 mm(3) Gradia-DP, and 0.011 mm(3) Tetric-EC). Operator-cavity type interaction and surface area of restorations did significantly influence the volume wear rates (p < 0.05). The three wear patterns: fatigue cracks at heavy occlusal contact area/OCA, pitting at light OCA, and scratches/striations along the food escape pathways were evident. The three hybrids differed significantly in volume wear due to material and operator variables. CLINICAL RELEVANCE: Clinically, operators and cavity type can affect restorations' wear magnitude but do not contribute to increased functional risk of fracture or harmful effect on pulp and periodontal biocompatibility.

Long-term bonding to eroded dentin requires superficial bur preparation.

OBJECTIVES: This study aims to evaluate the influence of different surface preparation techniques on long-term bonding effectiveness to eroded dentin. MATERIALS AND METHODS: Dentin specimens were eroded by pH cycling or were left untreated as control, respectively. Five different "preparation" techniques were applied: (1) cleaning with pumice, (2) air abrasion, (3) silicon polisher, (4) proxo-shape, and (5) diamond bur. The three-step etch-and-rinse adhesive OptiBond FL (O-FL; Kerr) and the mild two-step self-etch adhesive Clearfil SE Bond (C-SE; Kuraray) were evaluated. Micro-tensile bond strength was measured after water storage for 24 h and 1 year. Fracture analysis was performed by stereomicroscopy and SEM. Interfaces were characterized by TEM. Differences were statistically analyzed with a linear mixed effects model (α = 0.05). RESULTS: Erosion reduced bond strength in all groups, but this effect was less prominent when eroded dentin was prepared by diamond bur. Storage lowered bond strength in almost all groups significantly, but this ageing effect was more prominent for the eroded surfaces than for non-eroded controls. Whereas after 1-year control specimens revealed superior bond strength with the three-step etch-and-rinse adhesive (O-FL), the mild two-step self-etch adhesive (C-SE) revealed a better 1-year bond strength to eroded dentin. The interface at eroded dentin appeared very prone to degradation as was shown by the increased amount of adhesive failures and by the silver infiltration detected by TEM. CONCLUSIONS AND CLINICAL RELEVANCE: Although a minimally invasive approach should clinically always be strived for, superficial preparation (or minimal roughening) with a diamond bur is recommendable for long-term bonding to eroded dentin.

Current concepts and techniques for caries excavation and adhesion to residual dentin.

The advent of "Adhesive Dentistry" has simplified the guidelines for cavity preparation enormously. The design and extent of the current preparations are basically defined by the extent and shape of the caries lesion, potentially slightly extended by bevelling the cavity margins in order to meet the modern concept of minimally invasive dentistry. New caries excavation techniques have been introduced, such as the use of plastic and ceramic burs, improved caries-disclosing dyes, enzymatic caries-dissolving agents, caries-selective sono/air abrasion and laser ablation. They all aim to remove or help remove caries-infected tissue as selectively as possible, while being minimally invasive through maximum preservation of caries-affected tissue. Each technique entails a specific caries-removal endpoint and produces residual dentin substrates of different natures and thus different receptiveness for adhesive procedures. This paper reviews the newest developments in caries excavation techniques and their effect on the remaining dentin tissue with regard to its bonding receptiveness.

Guided Endodontics: Use of a Sleeveless Guide System on an Upper Premolar with Pulp Canal Obliteration and Apical Periodontitis.

Guided endodontics has been used for the treatment of anterior teeth with a successful outcome. This approach is not only limited to anterior teeth because it can also be used for the treatment of premolars and molars. However, in such cases, space may be a limitation because a long bur has to be used in addition to the guide being placed on top of the teeth. The aim of this case report was to present a novel guided endodontics technique using a sleeveless 3-dimensional-printed guide. This design can reduce vertical space, allowing an open view of the tooth and irrigation during drilling. A 46-year-old female patient consulted the endodontic department with intermittent pain around tooth #5. Tooth #5 presented pain upon percussion and responded negative to a cold test. The initial periapical radiograph revealed an apical radiolucency with pulp canal obliteration. Clinically, there was no sinus tract. The tooth was diagnosed with pulp necrosis and symptomatic apical periodontitis. Guided endodontic treatment was performed with a sleeveless 3-dimensional-printed guide and long neck carbide bur with a head diameter of 1 mm to drill a minimally invasive access cavity up to the root canal. A completely healed apical area of tooth #5 was visible after 1 year on periapical radiographs. This technique seems to be a promising alternative in comparison with the conventional guided endodontic guide design for the negotiation of pulp canal obliteration in cases in which vertical space is limited.

CBCT-based assessment of the anatomic relationship between maxillary sinus and upper teeth.

OBJECTIVES: To describe the relationship between maxillary sinus (MS) and upper teeth based on cone beam computed tomographic scans (CBCT). MATERIALS AND METHODS: Based on CBCT maxillary imaging data of 147 patients, distance between MS and apices of canines and posterior maxillary teeth were assessed. Distances between tooth roots and sinus were classified into three groups: distant (>2 mm), close (<2 mm) or in contact with MS. Teeth with apical lesions and uncommon root configurations were excluded. RESULTS: In total, 1075 teeth of maxillary canines, upper premolars and upper molars were included in this study. Teeth most often in contact with MS were the second (89%) and first (81%) maxillary molar without any significant difference (p = 0.19). Roots most often in contact with MS were the mesiobuccal and distobuccal root of the second molar (85% and 76%; p = <0.01) followed by the palatal root of the first molar (73%). A fifth of the upper canines are situated less than 2 mm from MS. CONCLUSIONS: More than four out of five upper molars (first and second) are in a close relationship to the MS. Knowledge of the anatomical relationship between posterior maxillary teeth and the MS is important for diagnosis and treatment in this area.

Cleaning efficacy and uncontrolled removal of dentin of two methods of irrigant activation in curved canals connected by an isthmus.

The aim of this study was to compare the efficacy of UAI with ESI, sonic activation with Eddy® and syringe irrigation in removing debris, and dentin removal during canal irrigation. Twenty-four mandibular molars containing isthmus type V and with a mean curvature of 32.5° were instrumented and divided into three groups for final irrigation: UAI with ESI, sonic activation with Eddy and syringe irrigation. The samples were scanned in a SkyScan 1172 micro-CT device for pre-, post-instrumentation and post-irrigation images and analysis of dentin removal. Statistical analysis was performed using Wilcoxon, Kruskal-Wallis and Dunn tests. UAI and sonic activation significantly improved debris removal (P < 0.05). No significant difference was observed regarding dentin removal between the groups (P > 0.05), although higher values were found for UAI. Sonic activation with Eddy® showed to be an effective and safe device since it was able to remove debris without causing damage to the canal walls.

Influence of CBCT-based volumetric distortion and beam hardening artefacts on the assessment of root canal filling quality in isthmus-containing molars.

OBJECTIVES: To evaluate the influence of artefacts in cone beam CT (CBCT) images of filled root canals in isthmus-containing molars. METHODS: 10 teeth presenting canals with an isthmus were instrumented and filled with a thermoplasticised obturation technique. The teeth were scanned using a micro-CT device and two CBCT devices: 3D Accuitomo 170 (ACC) and NewTom VGi evo (NT), with different acquisition protocols: larger and smaller voxel size. Three examiners assessed the CBCT images for: (1) detection of filling voids; (2) assessment of under- or overestimation of the filling material and (3) resemblance of CBCT images to the reference standard. Analyses of Task 1 yielded accuracy, sensitivity and specificity for detection of filling voids. For tasks 2 and 3, statistical analysis was performed using Wilcoxon test. The level of significance was set at p < .05. RESULTS: For Task 1, ACC showed higher sensitivity, whereas NT presented higher specificity. No significant difference was found between the protocols in ACC, however, for NT, differences between protocols were significant for all diagnostic values. In Task 2, visualisation of the filling was overestimated for NT, while for ACC, underestimation was observed. For Task 3, images with smaller voxel size were more similar to the reference image, for both CBCT devices. CONCLUSIONS: Different artefacts compromise the detection of filling voids on CBCT images of canals in mandibular molars with isthmus. ACC and NT present rather similar diagnostic accuracy, even though artefact expression remains device-specific.