Pedro Tortamano

Recent advances of ultrasound imaging in dentistry – a review of the literature

Ultrasonography as an imaging modality in dentistry has been extensively explored in recent years due to several advantages that diagnostic ultrasound provides. It is a non-invasive, inexpensive, painless method and unlike X-ray, it does not cause harmful ionizing radiation. Ultrasound has a promising future as a diagnostic imaging tool in all specialties in dentistry, for both hard and soft tissue detection. The aim of this review is to provide the scientific community and clinicians with an overview of the most recent advances of ultrasound imaging in dentistry. The use of ultrasound is described and discussed in the fields of dental scanning, caries detection, dental fractures, soft tissue and periapical lesions, maxillofacial fractures, periodontal bony defects, gingival and muscle thickness, temporomandibular disorders, and implant dentistry.

Patient outcomes and procedure working time for digital versus conventional impressions: A systematic review

Statement of problem. Limited evidence is available comparing digital versus conventional impressions from the point of view of patient preference. Purpose. The purpose of this systematic review was to identify and summarize the available literature related to patient‐centered outcomes for digital versus conventional impression techniques. Material and methods. The databases Medline, Cochrane, Science Direct, Scopus, and Embase were electronically searched and complemented by hand searches. All published papers available on the databases from 1955 to July 2016 were considered for title and abstract analysis. Results. A total of 2943 articles were initially identified through database searches, of which only 5 met the inclusion criteria for qualitative analysis. Four studies comparing patient‐reported outcome measures (PROMs) between conventional and digital impressions revealed that the digital technique was more comfortable and caused less anxiety and sensation of nausea. Only 1 study reported no difference between the techniques regardless of patient comfort. Two studies reported a shorter procedure for the conventional technique, whereas 3 studies reported a shorter procedure for the digital technique. Conclusions. A lack of clinical studies addressing patient outcomes regarding digital prosthodontic treatments was observed among the included articles. However, current evidence suggests that patients are more likely to prefer the digital workflow than the conventional techniques.

Comparative analysis of imaging techniques for diagnostic accuracy of peri-implant bone defects: a meta-analysis

OBJECTIVE The aim of this study was to systematically review the literature regarding diagnostic accuracy of imaging techniques in detecting peri-implant bone defects. STUDY DESIGN The search was performed in 8 electronic databases from April to May 2016 and updated in September 2016. Studies that assessed imaging techniques to detect peri-implant bone defects were analyzed. RESULTS The search yielded 680 articles published from 1991 to 2016. Of these, 12 studies were considered eligible for this review. The selected studies evaluated the use of cone beam computed tomography (CBCT), intraoral radiography (IR), computed tomography, and panoramic radiography. The sensitivity for CBCT was 59%, whereas the specificity was 67%. For IR, the sensitivity was 60%, and the specificity was 59%. Area under the curve values in receiver operating characteristic (ROC) analysis were 69% for CBCT and 63% for IR. For CBCT, the highest value for positive predictive value was 0.94, negative predictive value was 0.98, positive likelihood ratio was 21.3, and negative likelihood ratio was 1.28. For IR, the highest positive predictive value was 1.0, negative predictive value 1.0, positive likelihood ratio 50.0, and negative likelihood ratio 0.70. The highest diagnostic odds ratio was 80 for CBCT and 4.45 for IR. No conclusion could be drawn for additional techniques. CONCLUSIONS Both CBCT and IR showed a clinically acceptable performance for assessing peri-implant bone defects.

Accuracy of linear measurements around dental implants by means of cone beam computed tomography with different exposure parameters

OBJECTIVES The aim of this study was to determine the accuracy of linear measurements around dental implants when using CBCT unit devices presenting different exposure parameters. METHODS Dental implants (n = 18) were installed in the maxilla of human dry skulls, and images were obtained using two CBCT devices: G1-Care Stream 9300 (70 kVp, 6.3 mA, voxel size 0.18 mm, field of view 8 × 8 cm; Carestream Health, Rochester, NY) and G2-R100 Veraview® (75 kVp, 7.0 mA, voxel size 0.125 mm, field of view 8 × 8 cm; J Morita, Irvine, CA). Measurements of bone thickness were performed at three points located (A) in the most apical portion of the implant, (B) 5 mm above the apical point and (C) in the implant platform. Afterwards, values were compared with real measurements obtained by an optical microscopy [control group (CG)]. Data were statistically analyzed with the significance level of p ≤ 0.05. RESULTS There was no statistical difference for the mean values of bone thickness on Point A (CG: 4.85 ± 2.25 mm, G1: 4.19 ± 1.68 mm, G2: 4.15 ± 1.75 mm), Point B (CG: 1.50 ± 0.84 mm, G1: 1.61 ± 1.27 mm; G2: 1.68 ± 0.82 mm) and Point C (CG: 1.78 ± 1.33 mm, G1: 1.80 ± 1.09 mm; G2: 1.64 ± 1.11 mm). G1 and G2 differed in bone thickness by approximately 0.76 mm for Point A, 0.36 mm for Point B and 0.08 mm for Point C. A lower intraclass variability was identified for CG (Point A = 0.20 ± 0.25; Point B = 0.15 ± 0.20; Point C = 0.06 ± 0.05 mm) in comparison with G1 (Point A = 0.56 ± 0.52; Point B = 0.48 ± 0.50; Point C = 0.47 ± 0.56 mm) and G2 (Point A = 0.57 ± 0.51; Point B = 0.46 ± 0.46; Point C = 0.36 ± 0.31 mm). CONCLUSIONS CBCT devices showed acceptable accuracy for linear measurements around dental implants, despite the exposure parameters used.

Assessment of the Stress Transmitted to Dental Implants Connected to Screw-Retained Bars Using Different Casting Techniques

Passive fit of the prosthetic superstructure is important to avoid complications; however, evaluation of passive fit is not possible using conventional procedures. Thus, the aim of this study was to check and locate mechanical stress in bar restorations fabricated using two casting techniques. Fifteen patients received four implants in the interforaminal region of the mandible, and a bar was fabricated using either the cast-on abutment or lost-wax casting technique. The fit accuracy was checked according to the Sheffields test criteria. Measurements were recorded on the master model with a gap-free, passive fit using foil strain gauges both before and after tightening the prosthetic screws. Data acquisition and processing was analyzed with computer software and submitted to statistical analysis (ANOVA). The greatest axial distortion was at position 42 with the cast-on abutment technique, with a mean distortion of 450 μm/m. The lowest axial distortion occurred at position 44 with the lost-wax casting technique, with a mean distortion of 100 μm/m. The minimal differences between the means of axial distortion do not indicate any significant differences between the techniques (P = 0.2076). Analysis of the sensor axial distortion in relation to the implant position produced a significant difference (P < 0.0001). Significantly higher measurements were recorded in the axial distortion analysis of the distal sensors of implants at the 34 and 44 regions than on the mesial positions at the 32 and 42 regions (P = 0.0481). The measuring technique recorded axial distortion in the implant-supported superstructures. Distortions were present at both casting techniques, with no significant difference between the sides.

Clinical and Histomorphometric Evaluation of Fresh Frozen Bone Allograft in Sinus Lift Surgery

PURPOSE The aim of this prospective clinical study was to evaluate the clinical and histomorphometric data of newly formed bone tissue from fresh frozen human allograft in sinus lift surgery. PATIENTS AND METHODS Thirty-three sinus lift procedures were performed in 20 patients, divided into two groups. The control group (n = 8) received autogenous bone from the mandibular ramus, and the experimental group (n = 12) received fresh frozen bone (FFB) allograft in chips. After 6 months, 52 implants were placed and 50 biopsies were collected for histomorphometric analysis. Cone beam computed tomography scans were performed at preoperative, immediate postoperative, and delayed postoperative time intervals to assess the degree of graft volume loss. RESULTS There was no statistically significant difference between groups as regards degree of graft volume loss (p = .983), total bone area (p = .191), remaining particles (p = .348), and proportion of active osteoblasts (p = .867). There was a statistically significant difference in the vitality rate between the groups (p = .043). In both groups, all implants were clinically osseointegrated after 4 months. CONCLUSION FFB allograft was shown to be a feasible substitute for autogenous bone graft in sinus lift surgery.

Accuracy of a self-perforating impression tray for dental implants.

STATEMENT OF PROBLEM Difficulties are involved in impression making with conventional open impression trays. PURPOSE The purpose of this study was to evaluate the accuracy of transferring implant impressions with a self-perforating impression tray. MATERIAL AND METHODS A reference model of a mandible was fabricated, and 4 implants were placed in the regions of the first premolars and lateral incisors (implants 1, 2, 3, 4). Ten impressions of the reference model with polyvinyl siloxane were made for each group; control (conventional open impression tray) and test (self-perforating impression tray; Miratray Implant). A metal bar was screw-retained on implant 1, and the gaps generated at the vestibular face of implants 3 and 4 were measured by optical microcopy. The 2-way ANOVA and least square difference post hoc test were used (α=.05). RESULTS Higher mean (±SD) values were obtained for the test group than for the control group for both implants: implant 3: 150 ±84 μm for the test group, 73 ±63 μm for the control group (P=.019); implant 4: 129 ±65 μm for the test group, 62 ±61 μm for the control group (P=.04). CONCLUSION The self-perforating impression tray provided less accuracy than the conventional open tray.

Influence of Abutment Surface Treatments on Screw Loosening of Morse Taper Implants

Purpose: To evaluate the effect of blasting and bonding on abutment surface to prevent screw loosening in Morse taper connections. Material and Methods: Twenty-eight Morse taper connection implants were divided into 4 groups: no treatment (G1), blasting (G2), bonding (G3), and blasting + bonding (G4). In groups G2 and G4, the abutments were blasted with aluminum oxide granules; in groups G3 and G4, the conical abutment region was covered with a thin layer of bond thread lock agent. In all implants, the abutment-implant joint was tightened at a torque of 35 Ncm. The specimens were submitted to the mechanical cycling, under an oblique load for 1.0 × 106 cycles. The torque was measured with a digital torque meter. Data were analyzed by the t test, one-way analysis of variance, and Tukey tests (95%). Results: The loosening strength was significantly higher in group G4 (35.83 ± 3.02 Ncm). There was no significant difference among groups G1 (25.86 ± 1.96 Ncm), G2 (25.86 ± 3.29 Ncm), and G3 (26.14 ± 2.12 Ncm). Conclusion: The association of blasting and bonding on abutment surface can be used to prevent screw loosening in Morse taper implants.

Bone defect rehabilitation using lyophilized bone preshaped on a stereolithographic model

Bone grafting provides ideal conditions to the patient′s rehabilitation with dental implants. In addition, prototyped tridimensional models allow the surgical procedure to be simulated and enable important anatomic structures to be visualized. To present a bone defect rehabilitated with xenogenic bone preshaped on a stereolithographic model and the follow-up after 7 years of treatment. The present case report describes a bone defect rehabilitated with a lyophilized bone block preshaped on a stereolithographic model. The patient, a 56-year-old woman, was referred to the dental office presenting a bone defect in the anterior maxilla. Bone regeneration intervention was performed with xenogenic grafting and barrier membrane. The follow-up of the postoperative period and after 7 years is presented. After 7 years, the tomographic exam showed the maintenance of bone at the grafted site, representing the long-term success of the treatment.

Erratum to: Decontamination of dental implant surfaces by means of photodynamic therapy

Erratum to: Lasers Med Sci DOI 10.1007/s10103-012-1148-6 The original version of this article, unfortunately, contains an error. The energy was erroneously calculated based on an irradiation of 40mW (input power), not with 30mW as it was originally presented (output power). For this reason, the energy should be 5.4 J (for 3 min of irradiation) and 9 J (for 5 min) and not 7.2 and 12J, respectively.