Quintessence International, 05/2022

Objectives: The aim of this in vitro study was to compare the shear bond strength of a CAD/CAM resin-based composite restoration material with a lithium-disilicate-ceramic restoration material on human dentin. In addition, the influence of the chosen adhesive system should be investigated. Method and materials: Thirty cylindrical specimens each were fabricated from the composite resin-based material Grandio Blocs (GB) and the ceramic IPS e.max CAD (IEM). In each case, 15 specimens were bonded to human dentin samples using the adhesive system recommended and provided by the manufacturer. For 15 additional specimens, the adhesive systems were interchanged. After water storage (4 weeks) and thermocycling (5,000 cycles between 5°C and 55°C), the shear bond strength, the fracture modes, and the Adhesive Remnant Index (ARI) were determined. All data were statistically evaluated (Kruskal-Wallis test; P < .05). Results: The shear bond strength of IEM in combination with the manufacturer’s recommended adhesive system was statistically significantly higher than in those of all other groups (P < .05), resulting in 39.24 ± 7.73 N/mm2. For IEM, adhesive fracture mode was the only mode found, while adhesive and mixed fracture modes occurred in both GB groups. Significantly more adhesive/restoration material remnants (ARI) remained on the dentin surfaces in both GB groups (P < .05). Conclusion: For IEM the adhesive system recommended by the manufacturer should be used. For the GB samples, the choice of adhesive system had no influence on the shear bond strength. With GB, fracture may occur partly within the material under heavy load. Schlagwörter: CAD/CAM, fracture mode, Grandio Blocs, IPS e.max CAD, nano-hybrid resin-based composite, shear bond strength, thermocycling

Objective: The aim of this case series was to test various personalized, CAD/CAM-manufactured orthodontic extrusion appliances. The appliances were characterized by high rigidity and manufacturing precision. In addition, the orthodontic force vector could be precisely and three-dimensionally planned. Method and materials: After a comprehensive diagnosis of three patients with deep fractured teeth by an interdisciplinary team, each patient’s personalized extrusion protocol was determined (slow or rapid extrusion). Based on an intraoral scan, the personalized extrusion appliances were then digitally planned and manufactured using selective laser melting. The force vector was also precisely planned during this process. The appliances were inserted, and the force on the teeth to be extruded was precisely applied in accordance with the extrusion protocol. After extrusion, the teeth were retained and, if necessary, permanently restored. Results: The target teeth of all three patients were successfully extruded. Furthermore, good cleanability and high wearing comfort of the appliances were maintained throughout treatment, as was the precise application of force. Conclusion: The effectiveness of the tested digital workflow for precise and simplified orthodontic extrusion was clinically proven. The workflow guaranteed the following throughout treatment: precise planning and application of the force system; improved periodontal hygiene; and improved wearing comfort of the appliance, without affecting the patient’s existing occlusion. Schlagwörter: CAD/CAM, case report/series, orthodontic anchorage procedures, orthodontic appliance design, orthodontic 
extrusion, root fractures

Objectives: To systematically review indexed literature that assessed the association between periodontal diseases and the ABO blood group. Method and materials: The addressed focused question was “Is there an association between periodontal diseases and the ABO blood group?” Indexed databases were searched without time and language restrictions using different key words. Original studies, case reports, and case series that assessed the association between periodontal diseases and the ABO blood group were included in a meta-analysis. The risk of bias was evaluated using the National Institutes of Health tool. Letters to the Editor, commentaries, and historical reviews were excluded. Results: A total of 17 studies including 8,543 individuals were included; periodontitis (n = 4,476), gingivitis (n = 1,582), and healthy (n = 1,610). The most frequent event rate of blood group phenotype in periodontitis was blood group type O 39.0 % (95% CI 0.35 to 0.43). The event rate of positive Rh was 90.7% (95% CI 0.89 to 0.92) compared to 9.2% (95% CI 0.06 to 0.13) for negative Rh. Fixed effect analysis showed that blood group AB had a protective value to periodontitis; odds ratio 0.66 (95% CI 0.50 to 0.80; P < .001). However, there was no significant association of blood group A, B, and O. In addition, there was no significant association between ABO blood group and gingivitis; odds ratios of blood group B and O were 1.18 (95% CI 0.80 to 1.67; P = .34) and 1.36 (95% CI 0.89 to 2.08; P = .16), respectively. Conclusion: There is a discrepancy among published observations regarding the effect of the ABO blood group on periodontium health. Further studies are needed with a large sample population to build more robust evidence. (Quintessence Int 2022;53:404–412; doi: 10.3290/j.qi.b2644845) Schlagwörter: ABO blood group, gingivitis, meta-analysis, periodontal diseases, periodontitis

Objective: The aim of this study was to compare the fracture behavior of cantilever fixed dental prostheses (FDPs) fabricated from 3Y-TZP, 4Y-TZP, or 5Y-TZP zirconia. Method and materials: Posterior cantilever FDPs (three groups, each n = 16) were digitally designed and milled. After sintering, eight specimens/group were stored in demineralized water for 72 hours; eight specimens/group were subjected to accelerated aging using chewing simulation with thermal cycling (1,200,000 × 50 N; 2 × 3,000 × 5°C/55°C; H2O, 2 minutes/cycle) and finally stored in demineralized water for 24 hours. The cantilever FDPs were then statically loaded to failure to determine fracture load. Phase transformation towards the monoclinic phase was controlled with x-ray diffractometry. Results: One failure was identified after accelerated aging in the 5Y-TZP group. Fracture load decreased with increasing yttria content and decreasing bending strength. Accelerated aging using chewing simulation with thermal cycling caused a significant decline in fracture load. All FDPs failed in the area of the prepared tooth and in proximity to the cantilever, where the largest bending moment occurred. The yttria content had no influence on the type of fracture. With increasing yttria content, the relation between deformation and fracture load decreased only slightly. On the surface of FDPs that had been subjected to chewing simulation, no phase transformation towards the monoclinic phase (eg, low temperature degradation) was detected. Conclusion: Within the limitations of a laboratory study, the data indicate that 3Y-, 4Y-, and 5Y-TZP may be employed as material for the fabrication of permanent posterior cantilever FDPs. However, more data are necessary to finally advocate the application of 5-Y-TZP. (Quintessence Int 2022;53:414–422; doi: 10.3290/j.qi.b2793243) Schlagwörter: cantilever fixed dental prosthesis, fracture load, 3Y-TZP, 4Y-TZP, 5Y-TZP, zirconia

Objective: To analyze dental procedures and operating time provided to medically compromised and uncooperative pediatric patients under general anesthesia (GA). Method and materials: This cross-sectional retrospective study reviewed hospital records of pediatric patients treated under day-care GA at a Malaysian university hospital between January 2013 and December 2019. Dental procedures were categorized into preventive, restorative, pulp therapy, extraction, and surgical procedures. Age groups were categorized into < 6 years (primary), 6 to 12 years (mixed) and > 12 years old (permanent), to represent different dentitions. The treatment and operating times under GA were compared between age groups, sex, and medical conditions. Results: A total of 595 patients (455 uncooperative healthy and 140 medically compromised) were included in the study. The mean age of the patients was 5.7 years. Male patients (58.3%) outnumbered female patients (41.7%). The most frequently performed procedure was primary tooth extraction. A higher number of surgical procedures were performed on children aged > 12 years compared to younger age groups (P = .001). Children with medical problems had more preventive (mean 3.85 ± 3.65) than restorative treatments (mean 2.66 ± 2.80) and the results were reversed for healthy children. The mean operating time was 64.71 ± 27.89 minutes. Regardless of health status, children > 12 years old had longer operating times, and the mixed dentition group had the shortest treatment durations. Conclusions: Different types of dental treatment modalities are provided under GA for pediatric patients and operating time was associated with age group. Findings will be useful to improve efficiency of management of pediatric dental cases under day-care GA. Schlagwörter: dental treatment, dental caries, general anesthesia, pediatric dentistry, restorative dentistry

A 31-year-old man presented with gingival mass-like lesions. The patient reported occasional bleeding from lesions; otherwise, the lesions were asymptomatic. Intraoral examination revealed multiple interdental red/purple soft, sessile, nodular lesions involving both the maxillary and mandibular buccal and lingual gingivae, with poor oral hygiene. After performing incisional biopsy, the patient was diagnosed with pyogenic granuloma. Subsequently, the patient underwent cleaning of his teeth and within only 3 days of dental cleaning, the patient reported rapid regression of all his lesions. Schlagwörter: gingival inflammation, gingival mass, pyogenic granuloma

Objective: The study aimed to evaluate healing in apicomarginal defects with amniotic membrane (AM) using 2D periapical radiography and 3D cone beam computed tomography imaging. Method and materials: Thirty-four patients with symptomatic apical periodontitis and apicomarginal communication were allocated to either the AM or control group. Clinical and radiographic assessment was performed at baseline and at 12 months using Molven criteria, modified Penn 3D criteria, and RAC and B indices at resected plane, apical area, cortical plate, and combined apicocortical area, respectively. Results: There was no significant difference in the healing outcome in 2D imaging (93.3% control and 86.7% AM) and 3D imaging (80.0% control and 53.3% AM) between the groups. With RAC scoring, a greater percentage of unhealed cases was observed in cortical plate. Radiographic buccal bone formation in the 3D imaging was evident only in six cases. However, both the groups depicted significantly greater percentage reduction in the size of the lesion in 2D than the 3D analysis (AM group 91.69 ± 15.99 2D, 76.06 ± 47.62 3D, P = .020) and (control group 92.06 ± 14.36 2D, 85.12 ± 18.55 3D, P = .005). Conclusion: No significant difference in healing was observed between the AM and the control groups with the use of both periapical radiography and CBCT imaging. Despite good clinical healing and radiographic apical bone fill, buccal bone formation was not evident in 3D imaging in most of the cases. Schlagwörter: amniotic membrane, apicomarginal defects, buccal bone formation, cone beam computed tomography, guided tissue regeneration

Objective: The term temporomandibular disorders (TMDs) encompasses a variety of disorders of the temporomandibular joint (TMJD) and the associated musculature (MMD). Occlusion and its role in the genesis of TMDs is one of the most controversial topics in this arena. The objective of the narrative review was to summarize the implications of TMDs and its relationship to dental occlusion in two scenarios: 1) TMD as an etiologic factor in dental occlusal changes; 2) The role of dental occlusion as a causative factor in the genesis of TMDs. Data Sources: Indexed databases were searched from January 1951 to August 2021 using the terms TMJ, TMD, temporomandibular disorders, temporomandibular joint, and dental occlusion. Conclusion: There is lack of good primary research evaluating true association and showing the cause-and-effect relationship between dental occlusion and TMD. Systematic reviews suggest that the role of occlusion as a primary factor in the genesis of TMDs is low to very low. However, a variety of TMDs can lead to secondary changes in dental occlusion. Distinction between the two is paramount for successful management. Schlagwörter: occlusion, temporomandibular disorders, temporomandibular joint