Objectives: Restoration fit is one of the prerequisites of clinical durability. It is controversial as to whether computer‐assisted design/computer‐aided milling (CAD/CAM) or lost‐wax fabrication methods result in more fit metal‐ceramic crowns. This in‐vitro study was conducted to examine the internal fit of porcelain fused to metal crowns fabricated using CAD/CAM and lost‐wax techniques during fabrication stages (framework, porcelain, cementation) through digital triple scanning, replica weighting, and observation with electron microscopy.Material and methods: Twenty uniform resin dies of prepared first maxillary molars were randomly divided into two groups according to the fabrication technique: lost wax and CAD/CAM. The internal fit was measured in all steps of completing the crowns (framework, porcelain, and cementation) using different methods, including triple scanning, replica weighting, and scanning electron microscopy. The data were statistically analyzed using t test, Pearson, and repeated measures analysis of variance (α = .05).Results: Triple scanning revealed no difference in the internal fit of CAD/CAM and lost‐wax groups in all the fabrication steps (p > .05). The replica weighting method showed no difference between groups in the framework step (p > .05), while the internal fit was significantly better in the CAD/CAM group after porcelain application (p < .05). After cementation, electron microscopy measurements showed no difference between CAD/CAM and lost wax groups (p > .05). The Pearson correlation test showed no significant correlation between electron microscopy, replica weighing, and triple scanning methods (p > .05).Conclusion: According to scanning electron microscopy as the superior evaluation method, the internal fit of cobalt–chrome PFM crown of both CAD/CAM and lost wax groups was within the acceptable clinical range and there was no significant difference between them. Triple scanning revealed no difference in the internal fit of framework and porcelain steps but a better fit after cementation. According to replica weighting, the internal fit in the porcelain step was higher than the framework.

Background. Zirconia has been used as a reliable core material in dental restorations for years; however, its bonding to resin cement is a matter of challenge. Physical, chemical, and combinations of these techniques have been investigated to boost the properties of zirconia surface bonding. The objective of this work was to evaluate the effect of hydroxyapatite coating as a chemical therapy in combination with physical modifications on the microshear bond strength of the resin cement over zirconia. Methods. In the present research, 60 sintered zirconia blocks (4 × 4 × 4 mm) were randomized into four groups of 15, including Al₂O₃ particle abrasion (group 1), HA coating (group 2), Al₂O₃ particle abrasion + HA coating (group 3), and Er, Cr: YSGG laser irradiation + HA coating (group 4). The microshear bond strength was determined by bonding the blocks to the resin cement. Results. The bond strengths (mean ± standard deviation) of modified zirconia surfaces were 16.93 ± 4.94 MPa, 16.14 ± 5.4 MPa, 19.4 ± 5.27 MPa, and 16.21 ± 3.7 MPa in groups 1–4, respectively. Test results of the ANOVA test revealed no significant difference regarding the bond strength values of zirconia surfaces to the resin cement between the studied preparation modalities ( ). Conclusion. Observations from the present study showed that HA coating can be as effective as the air-borne particle abrasion technique in improving bond strength to zirconia surfaces. Moreover, sandblasting by an aluminum oxide or Er, Cr: YSGG laser irradiation prior to HA coating of zirconia showed no significant effect on the reinforcement of bond strength values when compared to HA coating alone. The clinic hydroxyapatite coating alone or in combination with physical treatments improves the bond strength of zirconia to resin cement.

Background: Fibromatosis is a group of benign tumors originating from connective tissues of muscle, overlying fascia, periosteum, or aponeurosis. However, they might need several excisional resections, owing to compressive effects on adjacent vital structures. Case Report: Here, we discussed a case of submandibular fibromatosis in a 3-year-old girl. She underwent a conservative surgical ...

Amyloidosis is often caused by the abnormal extracellular accumulation of amyloid in organs and tissues. This condition, affecting the head and neck region, is typically localized, and may also involve the oral cavity, particularly the tongue and buccal mucosa. As a solitary manifestation, the localized amyloidosis occurring intraosseous is highly infrequent. In addition, localized amyloidosis has a great rate of recurrence. In this paper, a 50-year-old female patient with the chief complaint of pain in the anterior of the maxilla is reported. According to clinical examination, no significant pathologic lesion was seen. The radiographic image showed a radiolucent lesion around teeth four and five. The treatment of choice for the patient was an excisional biopsy. As amyloidosis diagnosis is clinically challenging, biopsy and histologic examination of lesions are necessary in this regard. Accordingly, it is concluded that long-term follow-up is mandatory in case of localized amyloidosis because late recurrence can occur in some cases.

Background: Atherosclerosis and periodontitis are chronic inflammatory diseases characterized by inflammation and tissue destruction. Porphyromonas gingivalis, a key pathogen in periodontal disease, is implicated in initiating inflammation and tissue damage. Objectives: Given the potential link between periodontitis and the development of atherosclerotic plaques, this study aimed to investigate the presence of P. gingivalis DNA in subgingival and atherosclerotic plaques obtained from cadavers at the Tehran Forensic Medicine Center. Methods: In this cross-sectional study, cadavers with a postmortem interval of 6 hours and atherosclerotic plaques in their coronary arteries, along with subgingival plaques exhibiting pocket depths exceeding 5 mm, were examined. Subgingival plaque samples were collected from the deepest sites, while atherosclerotic plaque samples were harvested. Real-time PCR was employed to detect the presence of P. gingivalis in all samples, and the McNemar test was used for data analysis. Results: A total of 25 cadavers were included in the analysis, and both subgingival and atherosclerotic plaque samples were assessed. P. gingivalis DNA was identified in 40% of subgingival plaque samples and 16% of atherosclerotic plaque samples. Moreover, all positive atherosclerotic plaque samples also tested positive for P. gingivalis in the subgingival plaque. McNemar's analysis revealed a statistically significant difference between the subgingival and atherosclerotic samples (P-value = 0.03). Additionally, a correlation coefficient of 0.53 was obtained. Conclusions: While the study has certain limitations, the findings indicate a significant association between the presence of P. gingivalis in subgingival and coronary atherosclerotic plaques. Further investigations are warranted to elucidate the precise role of this periopathogen in atherosclerotic plaque formation.