1,721,008 research outputs found
Endodontics: Rotary or reciprocating instrumentation. clinical uses and advantages
No full textOBJECTIVES The purpose of this Module is to critically describe the evolution of endodontic instrumentation techniques and of rotary and reciprocating instruments to identify their clinical advantages and limitations in the clinical practice. Morphological aspects, importance of bacteria contamination and other clinical aspects are described and discussed. MATERIALS AND METHODS All concepts and techniques described in this didactic Module are supported by an extensive analysis of the literature ranging from in vitro studies on the mechanics of movements to the microscopic analysis of alloys, passing through long-term clinical and microbiological studies on various endodontic instrumentation techniques. The most recent technological innovations in the endodontic field were subsequently analyzed. In particular, the application of heat treatment to rotary instruments has led to a significant reduction in the risk of fracture, even in the presence of canals with severe curvatures with mineralized or sclerotic dentin. The development and introduction of the reciprocating movement applied to NiTi instruments allowed a reduction in the operating sequences and it is proposed as a single-instrument technique. Different instrumentation techniques will be described, analyzed step by step and correlated according to the present clinical situation. In association with the instruments, some of the main endodontic motors that introduce torque and reverse function will be analyzed in order to control the speed and mechanical stress of the instrument, to prevent instrument fracture and to facilitate the operator in clinical practice. The authors will describe several clinical tech niques and the use of different instruments. RESULTS The first NiTi instruments, marketed around 25-30 years ago, presented only austenitic phase at room temperature. These instruments were rigid and presented a high risk of fracture. More recently, rotary NiTi instruments characterized of thermal or chemical treatment have been introduced, with presence of austenitic, martensitic and R phase at room temperature. These instruments have greater resistance, deformability, flexibility and shape memory, allowing their use in preparation of curved and complex endodontic canals reducing significantly the risk for fracture. The reciprocating movement is introduced in clinical practice with specific motors. The technique offer the possibility to prepare root canals with simple and moderately curved morphology. CONCLUSIONS The described techniques, per formed with heat treated rotating and reciprocating NiTi instruments, allow to approach to both simple and complex root canals with a lower risk of instrument fractures. The use of such complex endodontic techniques in complex anatomy canals is only possible after an adequate training of the operators to prevent any clinical error and fracture of the instrument. CLINICAL SIGNIFICANCE The use of the most suitable preparation technique allows to perform root canal treatment with greater safety and minor risks for intra-operative complications
Rehabilitation of a Wide Buccal Recession Using a Combination of Adhesive Prosthetic Procedures and Transmucosal Convergent Neck Implant to Replace a Lower Fractured Canine: Case Report with 6 Years Follow-Up
No full textObjectives: The presence of gingival buccal recession is a frequent problem especially in the canine area. The cortical buccal bone may be absent in presence of health normal lingual/palatal bone and of other periodontal pockets. The present case report describes a minimally invasive approach in a 76-year-old patient with previously endodontically treated lower canine affected by root fracture and by a serious chronic buccal recession. Methods: The tooth was characterized by a deep vestibular bone defect, lack of buccal bone and acute periapical lesion. After extraction, Maryland bridge was positioned on the edentulous area. A two-piece convergent neck transmucosal implant was inserted with a flapless approach after 6 months. Maryland bridge was left in place for additional 3 months. After this time, digital impressions were taken, and a customized abutment was positioned. A provisional crown was designed according to Biologically Oriented Preparation Technique (BOPT) concept and maintained for 6 months. A zirconia definitive crown was digitally designed and cemented with a polycarboxylate-based cement. The Pink Esthetic Score (PES) was used as an index to assess peri-implant soft tissue stability over time (preoperatively, at 9 months, at 12 months and 72 months). Results: The patient was followed for 6 years under a conventional hygienic recall program. No complications occurred, and the PES improved from 4 preoperatively to 8 at 9 months, 10 at 12 months and 13 at 72 months. Conclusions: The use of Maryland bridge prevented occlusal trauma on healing tissues and appeared to support bone and soft tissue healing for transmucosal implant placement. A stable aesthetic rehabilitation was achieved up to 6 years. © 2025 by the authors
Prosthetic rehabilitation of hyperbolic neck transmucosal implant using a digital workflow
No full textOBJECTIVESNew approaches for implant placement and new devices for prosthetic rehabilitation techniques are being developed to simplify both surgical and prosthetic phases and to obtain a predictable outcome.The purpose of this clinical case is to describe the advantages and limitations of a prosthetic digital workflow in presence of a single-tooth implant rehabilitation in the esthetic zone (anterior maxilla) using two-piece implant.MATERIALS AND METHODSA patient with a compromised upper right incisor, characterized by severe mobility, root resorption and chronic periapical lesion, underwent an atraumatic tooth extraction. Due to the absence of acute infection, immediate implant placement was scheduled.A two-piece implant was placed with the hyperbolic neck exposed approx. 1 mm above tissue levels (transmucosal placement). A Maryland Bridge restoration was designed before surgery through the acquisition of digital models using a digital intraoral scanner. The Maryland Bridge was cemented using adhesive system and dual cure cement. The restoration was used as temporary rehabilitation until the impression procedures.The prosthetic phase was performed after 3 months from implant insertion. A digital workflow was used. A scan body was placed directly on the transmucosal implant neck without the need for a secondary surgery. A digital impression was acquired using the intraoral scanner, converted into an .stl file and sent to the dental laboratory. Exocad software was used to prepare the customized abutment, the temporary crown and the definitive restoration from the 3D printed models obtained from digital impression.The provisional resin crown was designed according to the Biologically Oriented Preparation Technique (BOPT). The finishing line ended at the implant hyperbolic with a moderate compression of peri-implant soft tissues. The crown was maintained for 21 days. Then definitive zirconium-ceramic crown was cemented with a polycarboxylate cement.RESULTSNo complications were observed during the follow-up. Soft tissue adaptation to the hyperbolic neck was observed, with high stability up to the 18-month.CONCLUSIONSThe use of a two-piece implant placed with a transmucosal technique and associated with a digital prosthetic workflow allowed an optimal rehabilitation in a highly aesthetic area with a minimally invasive approach.CLINICAL SIGNIFICANCEThe combined use of a minimally invasive surgical technique with transmucosal approach represents the first step of the proposed protocol. The healing phase guided by BOPT technique concepts and the use of intraoral scanners play a 3D biological approach in the evaluation of tissue morphology. The development of a fully digital workflow is possible and increases the predictability of clinical cases where aesthetic results is an important requisite.Digital impression technique with intraoral scanner can be considered particularly useful in association with implants placed transmucosal
Retreatment of Experimental Carrier-Based Obturators with the Remover NiTi Instrument: Evaluation of Apical Extrusion and Effects of New Kinematics
Full text linkThe objective of this study is to evaluate the retreatment time and weight of apically extruded debris yielded by two different kinematics during the removal of different root canal filling materials. Forty straight single-rooted extracted teeth were instrumented with HyFlex CM files and obturated with two different techniques: 25.04 HyFlex experimental carrier-based obturators (Coltène/Whaledent, Altstätten, Switzerland) (group 1) or 25.04 single gutta-percha cones (Roeko Coltène/Whaledent, Altstätten, Switzerland) (group 2) and Guttaflow Bioseal as the sealer. Samples were divided into four subgroups (n = 10) according to the used kinematics for the removal of root canal filling materials: continuous rotation (A) or retreatment motion (B) with a Remover and HyFlex EDM Nickel-Titanium instruments activated with a CanalPro Jeni micromotor (Coltène/Whaledent, Altstätten, Switzerland). Time for retreatment was digitally recorded, and debris extruded from the apex was collected in Eppendorf tubes and weighted with an analytical balance. Data on retreatment time and apical extrusion were statistically analyzed with the Kruskal-Wallis test (p<0.05). Working length was achieved in all the retreated samples. The removal of root filling material resulted significantly faster with the Jeni mode (p<0.001), and the difference was significant for the removal of both filling materials (p<0.05). No significant differences on debris extrusion between single cone and experimental obturators groups were noted (p>0.05), and no significant differences between kinematics (continuous rotation vs. Jeni motion) were observed (p>0.05). All the tested retreatment strategies lead to an extrusion of material from the apex, and the weight of apically extruded debris was similar. The use of the innovative CanalPro Jeni kinematics accelerates the time for the removal of root filling materials
A multilevel analysis of platform-switching flapless implants placed at tissue level: 4-year prospective cohort study
Full text linkPurpose: To evaluate the factors affecting peri-implant marginal bone level of single platform-switched implants with a smooth neck placed at gingival level (tissue level) using a flapless technique. Materials and Methods: Consecutive healthy patients requiring dental implant rehabilitations were enrolled in this study. Titanium implants with a zirconium-oxide-blasted surface and a platform-switch neck tulip configuration were used. Loading was performed 3 months after insertion with a provisional resin crown and after approximately 15 days with a definitive ceramic crown. Peri-implant marginal bone level (MBL) was measured on periapical radiographs at 1, 3, 6, 12, 24, 36, and 48 months by a blinded assessor. The following parameters were evaluated: location (maxillary/mandibular), position (anterior/posterior), sex (male/female), smoke (yes/no), implant placement timing (immediate, early, delayed), gingival thickness (thin/thick), endodontically treated adjacent teeth (yes/no), and diameter (3.8/4.25/5.0 mm). Multilevel analyses exploring factors associated with MBL at 36 and 48 months were performed. Results: A total of 76 patients (42 women, 34 men; mean age: 55.6 ± 10.7 years) received 128 implant rehabilitations. The survival rate was 98.4%. MBL displayed an initial increase during the first months from insertion (preload period). Cumulative mean MBL at T48 was 0.99 ± 0.68, which was not statistically significant from the values at T24 to T36 (P >.05). Mandibular location, delayed implants, and presence of adjacent endodontically treated teeth showed higher bone loss at 36 months (P <.05). Interestingly, at 48 months, only implant placement timing showed statistically significant differences. Delayed implants showed increased bone loss compared with both early and immediate groups (P <.05). Multilevel analysis confirmed the statistical significance of implant location (P =.031; 95% CI: 0.031 to 0.659), endodontically treated adjacent teeth (P =.001; 95% CI:-1.228 to 0.859), and implant placement (P =.045; 95% CI: 0.003 to 0.337) as factors affecting MBL at 36 months. All the investigated parameters, with the only exception being the implant placement group (P =.020; 95% CI: 0.334 to 1.432), were not statistically significant at 48 months (P >.05). Conclusion: Platform-switched implants placed nonsubmerged with a flapless approach showed a reduced bone loss progression in the first 4 years, as MBL remained stable at longer times (36 and 48 months). Implants placed with early and immediate timing showed reduced bone loss compared with delayed implants
Factors Affecting Soft and Hard Tissues Around Two-Pies Transmucosal Implants: A 3-Year Prospective Cohort Study
Full text linkPurpose:This 3-year study aimed to evaluate hard and soft tissue modification around a two-piece implant characterized by a transmucosal hyperbolic neck in healthy consecutive patients with a need for single-tooth replacement. Materials and Methods: Two-piece implants (n = 66) were placed with a flapless technique in 56 patients (27 men; 29 women; mean age 55 ± 9 years): 16 immediately after root extraction (immediate group), 20 after 8 to 12 weeks (early group), and 30 after 10 or more months (delayed group). The transmucosal hyperbolic neck was exposed 1 to 1.5 mm above gingival level. Customized abutments were positioned 3 months later with the implant-abutment connection located approximately 1 to 1.5 mm above soft tissue level. Provisional cemented resin crowns were designed with the finishing line at the hyperbolic neck and then positioned to avoid excessive compression of soft tissue, to guide gingival contours. Twenty days later, a definitive metal-ceramic crown was cemented. In all patients, the gingival biotype (thin or thick) was also evaluated. The primary outcomes were as follows: 36-month implant survival rate, peri-implant marginal bone level (MBL, in mm) changes observed in single-blind on radiographs at 1, 3, 6, 12, 24, and 36 months (T1, T3, T6, T12, T24, and T36), and pink esthetic score (PES) at T6, T12, and T36 to analyze soft tissue adaptation after loading and crown application. The secondary outcomes were as follows: plaque score and bleeding on probing (BOP). Linear regression models and multilevel mixed logistic regression were used to detect any statistical difference of MBL according to operative parameters. Kruskal-Wallis one-way analysis of variance (ANOVA) on ranks was performed to assess statistical differences of PES at T6, T12, and T36. Results: The survival rate was 100%. The dropout rate was 1.79%. No infections, mucositis, or peri-implantitis were reported. Implants placed in thick-biotype tissues showed a statistically different lower bone loss at 36 months with respect to the thin biotype (P <. 05). At 36 months, the early group showed lower bone loss compared with the delayed group (P <. 05). Multilevel mixed logistic regression revealed that gingival biotype was the parameter that was most related to MBL variations (P =. 025). The PES value (mean ± SD) at T6 was 10.76 ± 1.19 (median: 11; range: 8 to 13; IQR: 10 to 12). The values statistically increased at T12 and T36, where the mean values were 11.76 ± 1.10 (median: 12; range: 9 to 13; IQR: 11 to 12) and 11.83 ± 1.03 (median: 12; range: 9 to 14; IQR: 11 to 13). Conclusion: MBL and soft tissue clinical parameters measured around two-piece hyperbolic-neck implants were stable during the 3-year follow-up and free from complications. The exposure of the hyperbolic neck for 1.0 to 1.5 mm allowed a flapless one-stage surgery, which supported fast adaptation of the soft tissues, evidenced by high PES values and low percentages of BOP. The results from the study imply a new simple approach in the clinical management of gingival and bone tissue. Int J Oral Maxillofac Implants 2020;35:1022-1036
Risks of aerosol contamination in dental procedures during the second wave of COVID-19—experience and proposals of innovative IPC in dental practice
Full text linkDental-care workers operate very close to the patient’s mouth and are at high risk of contamination by SARS-CoV-2. Droplets may be contaminated by patient’s saliva and exhaled breath particles. All asymptomatic patients should be considered as Coronavirus positive. All dental procedures must be revised after positive identification of SARS-Cov-2. Novel recommendations as the use of novel suction cannula designed for fast spray/saliva aspiration, use of Tyvek suits and innovative sprayhoods designed for dental-care worker protections are proposed to prevent virus transmission. New tailored operative and clinical procedures are being currently developed by university dental clinics and hospitals in attempt to reduce risk for dental workers and patients
Root canal obturation techniques. Bioceramics and traditional sealers towards the evolution of the techniques
No full textOBJECTIVES The aim of this didactic module is to describe the main root canal obturation techniques, the biomaterials used, their applications, limits and advantages. MATERIALS AND METHODS The main root canal obturation techniques are described, with particular attention to the scientific evidence, the clinical evaluation and some historical aspects. Biomaterials to seal the root canal are examined, describing their chemical physical and biological properties, such as the setting time and expansion, radiopacity, biointeractivity and bioactivity. RESULTS Root canal obturation must avoid the bacteria recolonization of previously instrumented root canal and prevent the contamination of the periapical bone. The filling material should provide a stable tridimensional seal of the end odontic space with no voids or gaps at the root canal-material interface. The materials must also be insoluble, radiopaque, biocompatible and non-toxic. The techniques and the materials should be easy to be used in complex cases and non-operator dependent. Classical root canal techniques, such as cold lateral compaction and warm vertical compaction demonstrated valid results in long term studies, when associated to gutta-percha and traditional sealers. Carrier-based techniques, developed 30 years ago, showed extremely predictable results, which may be attributable to their simple procedure. For this reason, carrier-based is considered one of the gold standard techniques nowadays. All the techniques necessitate of a sealers. The sealers are used to occupy the small porosities and filling defects, aiming to guarantee the long-term sta bility of root canal treatment. Traditional zinc oxide-eugenol cements and epoxy resin based sealers have been used for years with excellent clinical results documented in literature. Bioceramic calcium silicate based cements are a group of materials from MTA initially used for retrograde obturation during root-end surgery. Bioceramics have innovative properties such as excellent biocompatibility, the ability to set in presence of moisture, the ability to expand and to nucleate apatite. Cold filling techniques, such as single-cone and lateral compaction, are recommended for these cements. Their principal clinical applications are elements with perforations or canal aberrations, wide apexes, large periapical bone defects and infected root canals. CONCLUSIONS Several materials are now clinically available. Knowledge and proficiency of both materials and technique is import ant in clinical practice. Coronal obturation and post-endodontic rehabilitation is crucial to prevent reinfection of the root canal over time. CLINICAL SIGNIFICANCE The evolution of cements, with the introduction of calcium-releasing bioceramics, represent a further step towards a more predictable endodontics using osteoinductive and osteoconductive materials. Biomaterials knowledge, and the proficiency of the operator in root canal obturation techniques are important aspects to obtain excellent and long-term clinical results
Secondary root canal treatment. When, how and why
No full textOBJECTIVES Endodontic retreatment procedures are increasing in clinical practice. The re-treatment aims to maintain a previous-ly treated tooth in which a periapical lesion is detected. Retreatment procedures should remove the previous filling material, provide an effective instrumentation and irrigation of the canal and provide a stable obturation and tooth reconstruction. These procedures are often complex and time consuming. The purpose of this Module is to describe the current endodontic retreat-ment techniques trying to identify their advantages and clinical limitations. MATERIALS AND METHODS The main causes of endodontic retreat-ment are considered, through the de-scription of the endodontic microbiolo-gy and the types of periapical lesions that can be observed in non-healed root canal treatments. The morphology of the endodontic canal after second instrumentation is described and some strategies are considered to remove the old filling material. RESULTS The conditions of endodontic retreat-ment are mainly due to the reinfection of the endodontic space, which can oc-cur due to coronal contamination (loss of the coronal seal) or to the presence of bacterial populations in areas of the canal not instrumented. Some bacteria, such as Treponema denticola and Por-phiromonas gingivalis, are highly pathogenic and are able to systemical-ly spread and reach different anatomi-cal districts, such as the heart, spleen, liver, and brain. One of the main problems of retreat-ment techniques is the possibility of pushing the infected debris of the ma-terial contained in the canal beyond the apex. These infected debris are respon-sible for acute post-operative pain and acute inflammatory phenomena. Ultrasonic instruments can support traditional manual instrumentation techniques and enhance the effect of the ir-rigants. Reciprocating instrumentation techniques can be used in the removal of the obturation material and in the instrumentation of the root canal. Secondary treatment can be surgically performed (endodontic surgery) where coronal access to the endodontic system is not feasible. Endodontic surgery shows high long-term success and survival rates in recent studies. CONCLUSIONS Endodontic retreatment still remains a complex and time consuming tech-nique. The use of ultrasonic instrumen-tation and reciprocating techniques al-low for better removal of the obturation material and a more effective instru-mentation of the canal. Retrograde endodontic surgery is a useful technique for maintaining the endodontical-ly treated element. CLINICAL SIGNIFICANCE The identification of a new periapical lesion, the non-healing and its exacer-bation in an endodontically treated element is attributable to the non-eradica-tion of pathogenic bacteria, or to a new reinfection of the canal space. For this reason, material removal, irrigation and instrumentation techniques play an important role in endodontic retreatment
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