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Purpose An in vitro study to compare the marginal fit of cobalt‐chromium (Co‐Cr) metal copings fabricated with selective laser melting (SLM), computer‐aided design and computer‐aided manufacturing (CAD/CAM) milling, and lost‐wax (LW) techniques, on abutments with two different antirotational features. Materials and Methods A total of 60 stainless steel abutments with the same length and convergence angles were fabricated using a numerical control machining. Half of the abutments had one flat plane, while the other half had three grooves as an antirotation feature. Thirty abutments of each kind were then divided into three subgroups, and metal copings were fabricated with SLM, CAD/CAM milling, or the LW technique (n = 10). The metal copings were cemented with polycarboxylate cement. Marginal gap measurements were performed using a stereomicroscope at a magnification of × 45 and data were analyzed with two‐way analysis of variance (ANOVA) tests. Results The LW (p = 0.002) and CAD/CAM (p < 0.001) techniques exhibited increased marginal gaps on the abutments with a three groove antirotational feature; however, no significant difference was detected with the SLM technique (p = 0.259). The copings fabricated with the SLM technique demonstrated significantly lower gap values in both abutment types (p < 0.001). Conclusion While all marginal gap values were within the clinically acceptable range (<120 µm), abutments with more antirotational grooves exhibited wider marginal gaps with the LW and CAD/CAM techniques.

Using implants and natural teeth in the same study design, the findings of the present study support the close relationship between MPO production and inflammation, and may speculate a potential for loading of dental implants, contributing to the MPO content of PISF.

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In the present study, immediate functionally loading did not negatively affect implant stability, marginal bone levels and peri-implant health when compared with conventional loading of single-tooth implants.

For monitoring of dental implants, practitioners seem to use simultaneously a variety of image-based and laboratory measurements. This longitudinal study was conducted to analyse the possible relationships between nitric oxide (NO) content of peri-implant sulcus fluid (PISF), marginal bone levels and implant stability in terms of resonance frequency analysis (RFA) at immediately (IL) and conventionally (CL) loaded mandibular molar dental implants from the same individuals. Dental implants were placed in 10 patients who had first molar loss bilaterally in the mandibular area. One site of the patient was determined as IL and the other site was CL. PISF samples, marginal bone level and RFA were taken for all dental implants during a 12-month follow-up period. For both types of loading, there were no significant changes at implant stability (ISQ) and PISF volume during the whole study period. The lowest total nitrite levels were observed at the end of 12 months. Marginal bone gain of 0.22 and 0.09 mm was noticed between 6 and 12 months in IL and CL groups, respectively. During the study period, negative correlation was noted between radiographic bone level and ISQ at both IL and CL sites; however, this correlation reached a significant level only at 6 months in CL implant group (P = 0.015). Although not significant, marginal bone loss seems to have a negative relationship with the implant stability values regardless of the mode of loading. NO metabolism around IL and CL dental implants may not demonstrate a significantly different pattern.

Single-unit implant or tooth-supported zirconia crowns may be considered acceptable treatment modalities for restoration of either missing or compromised posterior teeth.

The findings of this 12-month follow-up study support the association of NO in the bone metabolism around dental implants and further suggest the impact of different loading regimens on NO metabolism.