Quintessence International, 08/2018

Objective: The purpose of this study was to evaluate the impact of glide path preparation on the incidence of dentinal defects after preparation of severely curved canals using ProTaper Next, F6 SkyTaper, and One Shape instruments. Method and Materials: One hundred and forty human mandibular molars with mesiobuccal canals with angles of curvatures ranging between 25 and 35 degrees and radii ranging between 4 and 9 mm were assigned to seven homogenous groups (n = 20 teeth per group). In half of the teeth of each of the seven groups a manual glide path (size 15) was created prior to instrumentation. The root canals were instrumented using the three different types of instruments to an apical size 25. One group served as control as no canal preparation was performed. Roots were sectioned horizontally at 3, 6, and 9 mm from the apex and evaluated under a microscope using 25-fold magnification. The presence of dentinal defects (complete/incomplete cracks) was noted and analyzed using Fisher's exact test. Results: No defects were observed in the controls. All canal preparations created dentinal defects. More incomplete and complete cracks were found in the apical (n = 4) and the middle (n = 3) canal third than in the coronal (n = 1), without any significant differences between the three instruments (P > .05). Prior glide path preparation had no significant impact on the incidence of dentinal defects (P > .05). Conclusion: A glide path preparation seems not to be mandatory to reduce the risk of dentinal defects formation when using the tested instruments in severely curved canals. Schlagwörter: dentinal defects, F6 SkyTaper, One Shape, ProTaper Next, single-file systems

This case report describes the long-term follow-up of a patient with localized aggressive periodontitis over a 30-year period. A 16-year-old woman was referred for periodontal assessment after starting orthodontic treatment. The patient was treated initially by combined nonsurgical and antimicrobial therapy, and autotransplantation of maxillary third molars in place of maxillary first molars, followed by a regular supportive periodontal treatment program. This challenging case demonstrated that elimination of putative bacterial pathogens and long-term supportive periodontal treatments provide an effective treatment modality for localized aggressive periodontitis. Schlagwörter: Aggregatibacter actinomycetemcomitans, aggressive periodontitis, autotransplantation, implant, nonsurgical

Objective: To evaluate the efficacy of in-office tooth bleaching following application of either ozone (O3) or hydrogen peroxide (H2O2). Method and Materials: 32 participants were randomly distributed into two groups (n = 16 each). Participants' maxillary anterior teeth were treated with ozone (produced via a healOzone X4 device; Curozone) for 60 seconds in Group 1, or with 38% H2O2 for 20 minutes in Group 2. Tooth shades were evaluated by means of a colorimeter (CR-400, Minolta) measuring Vita classic shades in addition to L*a*b* shade values before and following bleaching in each group. A visual analog scale was used to evaluate tooth sensitivity before and after bleaching. Statistically significant differences were identified at P .05. Results: Teeth obtained lighter shades (increased L* and reduced a* and b* values) following bleaching in both groups (P .001). Both groups revealed comparable bleaching outcomes (P > .05). However, bleaching with ozone did not result in tooth sensitivity, whilst using H2O2 was accompanied with significantly increased bleaching sensitivity (P .001). Conclusion: Similar bleaching outcomes and lighter tooth shades (both for Vita shades and L*a*b* values) were obtained following in-office bleaching with either 60 seconds of ozone or 20 minutes of 38% H2O2. Notwithstanding, tooth sensitivity was significantly increased following bleaching with H2O2 in comparison to ozone. Ozone obviously does reduce the regularly clinically observed inconveniences of bleaching by means of H2O2; thus, ozone would seem worth considering for patients asking for in-office tooth bleaching. Schlagwörter: esthetic dentistry, healOzone machine, hydrogen peroxide, ozone, tooth bleaching

Objective: A randomized trial to assess clinical and radiographic outcomes of short versus standard dental implants placed with concomitant vertical bone augmentation. Method and Materials: Patients requiring dental implants were randomized to receive either 6-mm implants (experimental) or 10-mm implants with vertical augmentation (control). Custom load-bearing healing abutments were connected to allow for indirect resonance frequency analysis measurements. Standardized radiographs were taken at implant placement (baseline), and at 3 and 12 months. Implants were restored at 3 to 6 months, and final measurements were taken at 12 months. Results: Fifty patients with 25 implants per group were included. Five implants failed, four experimental and one control (84% and 96% cumulative survival rate, respectively). Short implants required significantly less surgical time (51.6 ± 23 versus 68.5 ± 35 minutes, P = .05). Implant stability quotients at baseline (67.9 ± 8.3 experimental and 70.8 ± 7.6 control, P = .215) and 12 weeks (70.17 ± 7.4 and 72.03 ± 5.9, respectively, P = .513) were similar and unchanged. Positive correlation was found between the two measurement methods (r2 = .6, P = .025). One-year average marginal bone loss was slightly lower for the experimental group (0.6 ± 0.16 mm) compared to the control group (0.86 ± 0.19 mm); however, this was not statistically significant (P = .287). Conclusion: Short dental implants may offer an alternative for implant placement in an atrophic jaw; however, they are associated with reduced first-year survival rate. Short dental implants should be used judiciously in light of this potential predicament, and alternatives assessed. Schlagwörter: bone loss, immediate restoration, regeneration, short implants, success, survival

Objective: To evaluate the survival and complication rate of 7-mm short, parallel-walled, conical-connection implants in daily practice. Method and Materials: This multicenter retrospective study included 219 consecutive patients who received 323 implants. Indication was limited vertical bone height preventing placement of implants longer than 7 mm. Placement and loading protocols were determined on a case-by-case basis and included placement in fresh extraction sockets and healed sites, and loading was either immediate, early, or delayed. Patients were followed for up to 33 months. Outcome measures were implant survival rate and any biologic or technical complications. Results: In total, eight implants in seven patients failed, accounting for the survival rate of 97.3% at implant level and 96.4% at patient level. The mean time to failure was 7.5 months and 10.2 months at the implant and patient level, respectively. The majority of patients (67.1%) received one implant and the placement was predominantly in healed sites (82.7%). Immediate loading was done for 21.4% of implants placed in the extraction site and for 21.3% of implants placed in healed sites. In most of the cases (71.8%) implants were placed in the premolar or molar position in the mandible. No complications were reported. Conclusion: These results suggest that in cases of limited vertical bone height, the short, parallel-walled, conical-connection implant can successfully support different prosthesis types in a wide variety of indications and loading protocols. Schlagwörter: conical connection, multicenter, parallel-walled, retrospective, short implant

Objective: Removal of third molars (3Ms) is one of the most common surgical procedures performed by dental surgeons. 3Ms that are associated with pathologic changes such as infection, nonrestorable caries lesions, cysts, tumors, and destruction of adjacent teeth and bone are under consensus for their removal. However, debate exists regarding the prophylactic removal of asymptomatic impacted 3Ms. This review attempts to establish indications for prophylactic extraction of 3Ms. Method and Materials: Clinical experience and a summary of the literature are presented concerning the effects of retained 3Ms in relation to caries and periodontal disease, dental arch changes and anterior crowding, cysts and other etiologies, mandibular fractures, temporomandibular pain, and aging of bone. Results: Nearly half of impacted 3Ms are associated with some form of pathology, most frequently caries (20%) and periodontal disease (17%). They increase the probability of fractures and their presence results in difficult fracture reduction and a higher rate of complication. The number of 3Ms decreases rapidly with age, with only 31% remaining at 38 years of age. Conclusion: Preventive removal of 3Ms at a young age is justified because retained 3Ms are at high risk of developing various pathologies. In addition, at older ages extraction of 3Ms becomes more complex, with an increased rate of complication due to deteriorated systemic physiologic conditions and changes in bone physiology. Schlagwörter: asymptomatic, extraction, impacted, preventive, third molars

Objective: To present an improved, accurate, and efficient method for planning and preparing an artificial socket for autotransplantation, by using a three-dimensional (3D) surgical guide and a replica of the transplanted donor tooth. The guide and the tooth replica were fabricated using a computerized 3D simulation. A case treated with this approach is presented. Method and Materials: Cone beam computed tomography (CBCT) and computerized 3D simulations (Simplant plus registration as stereolithography) were used for planning the optimal artificial socket position and dimensions, within the limitations of the alveolar bone borders and the adjacent teeth roots, and for producing a metal replica of the transplanted tooth. The replica was used to assure the correct socket preparation and orientation before extraction and replantation of the donor premolar. Results: The entire procedure time for autotransplantation of a permanent second premolar to the incisor site without the buccal plate was about 45 minutes. At 15 months' follow up, clinical examination of the transplanted tooth demonstrated both normal mobility and no sensitivity to cold stimulation. A radiographic examination revealed continuous root development and pulp obliteration. The adjacent teeth maintained their vitality with no pathologic signs. Conclusion: We present an improved technique for autotransplantation based on computerized 3D simulations and guidance for accurate dimensioning and optimal locating of the artificial socket relative to the alveolar bone borders and the adjacent teeth roots. This technique may significantly simplify the autotransplantation procedure and will probably also increase its success rate and use in young patients, even in cases with absence of a buccal plate. Schlagwörter: 3D printed template, dental socket, guided autotransplantation, modern autotransplantation, surgical template

The case of an 18-year-old woman with generalized short root anomaly (SRA) is presented, and the clinical management and challenges associated with this rare condition are discussed. The patient was referred for restoration of the edentulous maxillary left anterior region. Due to the SRA, the patient had previously received limited orthodontic treatment for the ectopic maxillary canines. The maxillary left canine failed during orthodontic traction, the left lateral incisor migrated in its region and had poor prognosis due to severe mobility. Therefore, it was extracted and the region was restored with an implant-supported cantilever metal-ceramic fixed partial denture. Radiographic examination revealed generalized SRA along with other dental anomalies. From the patient's family history, as well as from the physical, clinical, radiographic, biochemical, and histologic evaluations, we were unable to identify the etiology behind this unique combination of dental anomalies. Esthetics and function were successfully restored and a strict recall system was implemented in order to monitor and maintain the short-rooted teeth. The need to prevent tooth and periodontal tissue deterioration in patients with generalized short roots is emphasized. Schlagwörter: dental syndrome, displaced canines, short root anomaly, taurodontia, third molar agenesis, transposition