Quintessence International, 01/2018

Objective: Several methods for the evaluation of fit of computer-aided design/computer-assisted manufacture (CAD/CAM)-fabricated restorations have been described. In the study, digital models were recorded with an intraoral scanning device and were measured using a new three-dimensional (3D) computer technique to evaluate restoration internal fit. The aim of the study was to evaluate the internal adaptation and fit of chairside CAD/CAM-fabricated zirconia-reinforced lithium silicate ceramic crowns fabricated with different post-milling protocols. The null hypothesis was that different post-milling protocols did not influence the fitting accuracy of zirconia-reinforced lithium silicate restorations. Method and Materials: A master all-ceramic crown preparation was completed on a maxillary right first molar on a typodont. Twenty zirconia-reinforced lithium silicate ceramic crowns (Celtra Duo, Dentsply Sirona) were designed and milled using a chairside CAD/CAM system (CEREC Omnicam, Dentsply Sirona). The 20 crowns were randomly divided into two groups based on post-milling protocols: no manipulation after milling (Group MI) and oven fired-glazing after milling (Group FG). A 3D computer method was used to evaluate the internal adaptation of the crowns. This was based on a subtractive analysis of a digital scan of the crown preparation and a digital scan of the thickness of the cement space over the crown preparation as recorded by a polyvinylsiloxane (PVS) impression material. The preparation scan and PVS scan were matched in 3D and a 3D difference analysis was performed with a software program (OraCheck, Cyfex). Three areas of internal adaptation and fit were selected for analysis: margin (MA), axial wall (AX), and occlusal surface (OC). Statistical analysis was performed using 80% percentile and one-way ANOVA with post-hoc Scheffé test (P = .05). Results: The closest internal adaptation of the crowns was measured at the axial wall with 102.0 ± 11.7 µm for group MI-AX and 106.3 ± 29.3 µm for group FG-AX. The largest internal adaptation of the crowns was measured for the occlusal surface with 258.9 ± 39.2 µm for group MI-OC and 260.6 ± 55.0 µm for group FG-OC. No statistically significant differences were found for the post-milling protocols (P > .05). The 3D difference pattern was visually analyzed for each area with a color-coded scheme. Conclusion: Post-milling processing did not affect the internal adaptation of zirconia-reinforced lithium silicate crowns fabricated with a chairside CAD/CAM technique. The new 3D computer technique for the evaluation of fit of restorations may be highly promising and has the opportunity to be applied to clinical studies. Keywords: CAD/CAM, Celtra Duo, Cerec, marginal fit, internal fit, intraoral scanning, zirconia-reinforced lithium silicate ceramic

Objective: The aim of the present study was to investigate the associations between patients' understanding of periodontal disease, their individual compliance to homecare, self-reported periodontal disease, and how they have been educated regarding their oral health. Method and Materials: A cross-sectional study was performed by distributing questionnaires to patients at the University of Alberta Dental Clinic. A survey consisting of 45 questions was constructed in order to quantify patients' understanding of periodontal disease (section 1), where they received their information, how often they have been instructed by dental practitioners, their homecare habits (section 2), and their self-reported periodontal status (section 3). Results: In total, 286 surveys were analyzed from participants (92 males; 191 females; 3 other), with an age range of 15-87 years (mean 42.6 ± 15.1). Correctly answered questions ranged from 39.5% to 95.8%, the highest related to smoking and lowest regarding gingival pockets. Only 42.0% and 42.7% understood the purpose of periodontal probing and the difference between gingivitis and periodontitis respectively. Of the participants, 13.3% and 54.2% had never been shown how to clean their teeth or counselled regarding dietary habits from dental professionals respectively, and only 24.8% had been shown more than four times how to clean their teeth. A moderate association was found between sections 1 (knowledge) and 2 (habits/instruction), between sections 1 and 3 (self-reported health), and between sections 2 and 3. Conclusion: Moderate association between knowledge, homecare habits, instruction from dental professionals, and self-reported periodontal health was found. Patient understanding is lacking in certain areas and there seems to be a lack of patient education from dental professionals. As dental professionals improve patient instruction, there may be an improvement in patient compliance to homecare and periodontal health. Keywords: bone, bone loss, chronic periodontitis, gingival health, oral health literacy, plaque

This article reports a clinical case of a 10-year-old boy who sustained an avulsion of the maxillary right central incisor. The avulsed tooth was kept in adverse extraoral dry conditions for 26 hours from the moment of trauma until its replantation. Treatment guidelines for avulsed mature permanent teeth with closed apex were only partially followed. However, the clinical and radiographic findings after 10 years revealed acceptable functional outcome, in spite of ankylosis and root resorption of the replanted tooth, which was eventually treated cosmetically. Keywords: ankylosis, dental avulsion, dental trauma prognosis, replantation, root resorption

Objective: Surgical removal of third molars is often associated with complications. The aim of the present study was to analyze the incidence of complications following extraction of third molars relative to the risk factors. Method and Materials: This retrospective study included 463 patients who had mandibular third molar extraction (performed by a single surgeon, DSA) in the years 2001 to 2011. In total, 665 mandibular third molars were extracted. The average patient's age was 29 ± 11.30 years, median 26 years, and the patient age ranged from 13 to 75 years. Patients' records were obtained for medical/general data. Results: The overall prevalence of postsurgical complications was 17%. Dry sockets showed the highest incidence (11.6%). Partially impacted teeth showed the highest incidence of complications (67.3%). Cigarette smoking correlated with increased complications and dry sockets, and complications were more prevalent on the left side (62.8%). Conclusion: Complications after mandibular third molar extraction increase with age, level of impaction, side of extraction, and cigarette smoking. Keywords: cigarette smoking, dry sockets, mandible, partially impacted, tooth impaction, wisdom teeth

A technique is presented for severely impacted and dentigerous-cyst-related mandibular third molar removal, avoiding any associated risks. Case Presentation: A healthy patient complained about unpleasant smell and taste in the mouth and unilateral extraoral palpation of a protuberance, at the right corner of the mandible. Restricted field CBCT showed a severely impacted third molar, which penetrated the inferior cortical bone of the mandibular corner and was associated with a dentigerous cyst that had resorbed considerable bone in the region. Surgical exposure of the impacted tooth and cyst marsupialization procedures under local anesthesia were combined with orthodontic extrusion of the impacted tooth to facilitate third molar removal. Treatment resulted in successful bone formation and safe tooth removal. The symptoms gradually improved after the first surgery and were eliminated by 14 months later, when the third molar was removed. Follow-up examination 1 year after removal showed favorable periodontal conditions. Conclusion: Although it is not normally the first treatment of choice, orthodontically assisted impacted tooth removal is an alternative that can minimize the risk of compromised periodontium or injury to the adjacent tooth and the inferior alveolar nerve, as well as the risk of mandibular fracture, in complicated cases. Keywords: dentigerous cyst, extraction, impacted tooth, marsupialization, orthodontic extrusion, third molar

Primary burning mouth syndrome (BMS) is a chronic pain of a burning quality affecting the tongue and intraoral mucosa. Currently, there are no definite diagnostic criteria; therefore, the diagnosis is made by exclusion of potential local and systemic causes that could justify the burning sensation. The etiology behind primary BMS remains unclear; however, the most acceptable theories link primary BMS with neuropathic pain. This article provides a review of primary BMS diagnosis, mechanisms, and treatment with focus on the association of BMS with pain modulation. Preliminary data are presented suggesting a link between primary BMS and a faulty inhibitory pain system. Keywords: burning mouth syndrome, pain modulation, neuropathic pain

Objective: To determine the prevalence of the retromolar canal and its various patterns using cone beam computed tomography (CBCT). Method and Materials: CBCT images with the presence of mandibular third molars from August 2013 to May 2015 were retrospectively investigated. The presence of retromolar canal, its patterns, sides, as well as gender were evaluated by two observers. The pattern of retromolar canal was initially classified into three types: Type A, superior type; Type B, radicular-retromolar type; and Type C, dental type. During the investigation, two additional types were found and further classified: Type D, plexus type; and Type E, forward type. The distribution of retromolar canals between genders and sides was statistically analyzed with Pearson's chi-square test. Results: A total of 201 mandibular sites in 156 subjects (99 women, 57 men) were included. Among them, 128 sites had retromolar canals (63.68%). The presence of retromolar canal was not statistically related to gender or side. Most of the retromolar canals were the radicular-retromolar type (Type B, 38.10%), followed by the superior type (Type A, 29.93%), dental type (Type C, 19.73%), plexus type (Type D, 6.80%), and forward type (Type E, 5.44%). Conclusion: There was a high frequency of retromolar canals and these could be classified into five patterns. The clinician should be aware of this anatomical structure when performing surgical procedures involving the retromolar area. Keywords: bifid mandibular canal, cone beam computed tomography, inferior alveolar canal, retromolar canal

Objective: The aim of the present systematic review was to evaluate the periodontal tissue inflammation indexes in patients undergoing different orthodontic treatment. Method and Materials: The Cochrane Oral Health Group specialist trials, Medline, and Embase databases were used for the research. All the included studies had to report bleeding on probing (BOP) depth as primary outcome. Changes in probing depth, clinical attachment level, Gingival Index, and Periodontal Index were included in the review as secondary outcome measurements. Results: Ten studies reporting on 421 patients and different types of orthodontic treatment were selected for the analysis. Owing to the heterogeneity of studies present in the literature, it was not possible to perform a meta-analysis. Conclusion: Within their limits, the results showed an increase of periodontal parameters after orthodontic treatment, indicating that it influences the accumulation and composition of the subgingival microbiota and subsequently induces more inflammation and higher BOP. Keywords: bleeding on probing depth, orthodontic appliance, orthodontic treatment, ortho-perio, periodontal inflammation