Quintessence International, 01/2017

Background: With the Minamata Convention the use of mercury will be phased down, and this undoubtedly will have an effect on dental treatment regimens and economic resources. Composite resin restorations are considered viable alternatives to amalgam fillings; however, these will not be covered completely by health insurance systems in many countries. Recently, a high-viscosity glass-ionomer cement (hvGIC) processed with a resinous coating (RC) has been introduced, and has been marketed as a restorative material in load-bearing Class I cavities (and in Class II cavities with limited size), thus serving as a possible alternative to amalgam fillings. Objective: To discuss the outcome based on the evaluation presented in Part I of this paper, and to critically appraise the methodologies of the various studies. Results: Two of the included studies were industry-funded, and status of the other clinical trials remained unclear. Quality of study reporting was considered perfectible. The use of a light-cured nanofilled resin coating material would seem advantageous, at least when regarding short- and medium term outcomes. Conclusion: Within the respective indications and cavity geometries, the hvGIC/RC approach would seem promising, could merge the phase-down of mercury and the objectives of minimally invasive treatment to some extent, and might be a restorative alternative for patients suffering from allergies or not willing to afford other sophisticated or expensive techniques. These recommendations are based on studies evaluating EQUIA Fil (GC), but are not transferable to clinical perspectives of the glass hybrid successor product (EQUIA Forte; GC). Keywords: amalgam, Class I and Class II cavities, clinical trial, composite resin, high-viscosity glass-ionomer cement, Minamata Convention, minimum intervention dentistry, resin coating

Objective: No clinical data are available for the new computer-aided design/computer-assisted manufacture (CAD/CAM) material zirconia-reinforced lithium silicate (ZLS) ceramic. This study describes preliminary clinical results for indirect ZLS CAD/CAM restorations after 12 months. Method and Materials: Indirect restorations were fabricated, using the CEREC method and intraoral scanning (CEREC Omnicam, CEREC MCXL). Sixty-seven restorations were seated adhesively (baseline). Sixty restorations were evaluated after 12 months (follow-up), using modified FDI criteria. Two groups were established, according to ZLS restorations' post-processing procedure prior to adhesive seating: group I (three-step polishing, n = 32) and group II (fire glazing, n = 28). Statistical analysis was performed with Mann-Whitney U test and Wilcoxon test (P .05). Results: The success rate of indirect ZLS CAD/CAM restorations after 12 months was 96.7%. Two restorations clinically failed as a result of bulk fracture (failure rate 3.3%). No statistically significant differences were found for baseline and follow-up criteria (Wilcoxon test, P > .05). Statistically significant differences were found for criteria surface gloss for group I and group II (Mann-Whitney U test, P .05). Conclusion: This study demonstrates ZLS CAD/CAM restorations have a high clinical success rate after 12 months. A longer clinical evaluation period is necessary to draw further conclusions. Keywords: CAD/CAM, CEREC, clinical study, zirconia-reinforced lithium silicate ceramic

Objective: To evaluate and compare the volume of removed dentin, transportation, and centering ability of TRUShape (TRS; Dentsply Tulsa Dental Specialties) system with ProTaper Next (PTN; Dentsply Maillefer) by using micro-computed tomography (µCT). Method and Materials: Twenty extracted human mandibular first molars with two separate mesial canals with curvatures of 25 to 35 degrees were divided into two experimental groups (n = 20) according to the rotary nickel-titanium file system used in canal instrumentation as follows: group TRS and group PTN. Canals were scanned before and after instrumentation using µCT to evaluate root canal transportation, centering ratio, and volumetric changes. Data of canal transportation and centering ratio values were analyzed using independent t test. Volume changes data were statistically analyzed using Mann-Whitney test. Statistical significance level was set at P .05. Results: The PTN group had a significantly lower mean volume of removed dentin (2.09 ± 0.41 mm3) than the TRS group (2.77 ± 0.72 mm3) (P .05). At the coronal level, there was no significant difference in canal transportation (P = .170) and centering ratio (P = .111) between TRS and PTN groups. However, at the apical and middle levels, the PTN group had a significantly lower mean transportation value and higher centering ratio than the TRS group (P .05). Conclusion: Root canal preparation with the PTN system revealed better performance with fewer canal aberrations than the TRS system in curved root canals. Keywords: centering ratio, micro-computed tomography, ProTaper Next, root canal volume, transportation, TRUShape

Objective: The purpose of the study was to assess the clinical accuracy of a novel open-lattice-frame implant positioning system by evaluating the deviation between planned and actual implant positions on pre- and postoperative cone beam computed tomography (CBCT) images of patients treated with dental implants. Secondary aims were to record surgical time from first incision to end of implant surgery and start of suturing, and to record patient and surgeon satisfaction from the implant surgical procedure. Pre- and postoperative CBCT of 10 patients receiving 18 dental implants were used to generate implant angular deviations and implant shoulder and apex deviations. Mean angular deviation was 2.96 ± 1.31 degrees (range 0.75 to 5.60 degrees). Mean shoulder and apex deviations were 1.07 ± 0.49 mm (range 0.38 to 1.85 mm) and 1.35 ± 0.57 mm (range 0.52 to 2.19 mm), respectively. Mean time from first incision to start of suturing was 24 ± 7 minutes. Patient satisfaction ranged between 8 and 10, and surgeon satisfaction regarding the procedure ranged between 9 and 10, on a scale of 1 to 10. The open-lattice-frame implant positioning system provided adequate accuracy, and may aid in improving patient-related and surgeon-related outcomes by improving surgical accuracy and shortening surgical treatment duration. Keywords: accuracy, guided surgery, implant, planning

Objective: The primary objective of this study was to compare the accuracy and time efficiency of an indirect and direct digitalization workflow with that of a three-dimensional (3D) printer in order to identify the most suitable method for orthodontic use. Method and Materials: A master model was measured with a coordinate measuring instrument. The distances measured were the intercanine width, the intermolar width, and the dental arch length. Sixty-four scans were taken with each of the desktop scanners R900 and R700 (3Shape), the intraoral scanner TRIOS Color Pod (3Shape), and the Promax 3D Mid cone beam computed tomography (CBCT) unit (Planmeca). All scans were measured with measuring software. One scan was selected and printed 37 times on the D35 stereolithographic 3D printer (Innovation MediTech). The printed models were measured again using the coordinate measuring instrument. Results: The most accurate results were obtained by the R900. The R700 and the TRIOS intraoral scanner showed comparable results. CBCT-3D-rendering with the Promax 3D Mid CBCT unit revealed significantly higher accuracy with regard to dental casts than dental impressions. 3D printing offered a significantly higher level of deviation than digitalization with desktop scanners or an intraoral scanner. The chairside time required for digital impressions was 27% longer than for conventional impressions. Conclusion: Conventional impressions, model casting, and optional digitization with desktop scanners remains the recommended workflow process. For orthodontic demands, intraoral scanners are a useful alternative for full-arch scans. For prosthodontic use, the scanning scope should be less than one quadrant and three additional teeth. Keywords: 3D printed models, accuracy, CBCT model scan, desktop model scanner, digitalization, full-arch scans, intraoral scanner

Venous malformations are congenital, abnormally formed vessels, present at birth. They do not undergo regression with the growth of the patient. Due to the stagnation of blood flow in venous malformations, thrombosis and phlebolith formation may occur. Phleboliths are calcified thrombi which radiographically must be differentiated from calcified lymph nodes, sialoliths, foreign bodies, and other radiopacities. We report an extensive venous malformation in a 19-year-old woman with panoramic radiography demonstrating multiple phleboliths. Magnetic resonance imaging revealed the extension of the lesion into the hard palate and the masseter muscles superiorly, extending from the oropharynx to the tongue, inferiorly reaching the right clavicula and spreading between the right sternocleidomastoid muscle and strap muscles of the neck. The article is presented because the presence of phleboliths demonstrated on panoramic radiography is rarely described in the literature. Keywords: magnetic resonance imaging, panoramic radiography, phleboliths, venous malformation

Objectives: The objective of the present case series is to describe the histology and surface ultrastructure of augmented keratinized gingival mucosa in humans during the early healing phase after surgical placement of a xenogeneic collagen matrix. Method and Materials: Six patients underwent surgical augmentation of keratinized tissue by placement of a three-dimensional (3D) xenogeneic collagen matrix. Full-depth mucosal biopsies including original attached gingiva, augmented gingiva, and the separation zone were performed at baseline and at postoperative days 7 and 14. The specimens were stained with hematoxylin-eosin, Masson-trichrome, picrosirius red, and Papanicolaou's trichrome. Low-vacuum scanning electron microscopy (SEM) surface analysis was correlated with histology. Results: The separation zone was clearly visible upon histologic and SEM examination at 7 days. The portions of augmented mucosa consisted of well-structured, immature gingival tissue with characteristics of per secundam healing underlying a completely detached amorphous collagenous membrane-like structure of approximately 100 μm thick. At 14 days, histologic and ultrastructural examinations showed an almost complete maturation process. There were no detectable remnants of the collagen matrix within the newly formed tissues at either time point. Conclusions: Within their limits the results suggest that the 3D collagen matrix appears to play an indirect role during the early phase of wound healing by protecting the newly formed underlying tissue and guiding the epithelialization process. Keywords: collagen matrix, epithelium, gingiva, histology, scanning electron microscopy

Objective: The objective of the present systematic review was to evaluate, in patients with irreversible pulpitis affecting mandibular posterior teeth, if premedication with nonsteroidal anti-inflammatory drugs can increase the efficacy of inferior alveolar nerve block (IANB) if compared to placebo administration; if one anesthetic agent is more effective than another; if 1.8 mL injection is more effective than 3.6 mL injection to increase the efficacy of IANB; and if supplementary buccal injection is able to increase the efficacy of IANB as compared to a negative control/placebo group. Data Sources: Randomized controlled clinical trials investigating different aspects (technique, premedication with anti-inflammatory drugs, different anesthetic agents) were searched. Success of IANB, as defined in the studies, was considered as the primary outcome. A meta-analysis was performed evaluating relative risks (RRs). Electronic databases (Medline, Embase, Cochrane Central) were searched after preparation of an appropriate search string. After application of selection criteria, a total of 37 studies were included; 19 of them were considered in the meta-analysis. There was evidence of a difference in favor of the use of premedication with anti-inflammatory drugs (RR, 1.80; CI 95%, 1.50-2.14; P .0001). There was no evidence of a difference between articaine and lidocaine (RR, 1.05; CI 95%, 0.91-1.21; P = .94). With regard to the volume of anesthetic infiltrated, the computed RR was 1.17 (CI, 0.73-1.88) without any significant difference between the use of one or two cartridges (P = .52). The estimated RR for a supplementary buccal infiltration was 1.56 (CI, 1.00-2.42; P = .05). Conclusion: The use of premedication with anti-inflammatory drugs before IANB can increase the efficacy of the IANB. The type of anesthetic agent, the volume of anesthetic, and the use of a supplemental buccal infiltration do not seem to affect the efficacy of anesthesia. Keywords: inferior alveolar nerve block, local anesthesia, pulpitis, systematic review