Evidence map›Paper›PMID 41629929›Full record

ArticleBMC oral health2026

Comparison of marginal gap in implant-supported hybrid nanoceramic crowns fabricated by additive vs. subtractive manufacturing.

Shaimaa Omar, Enas A Elshenawy, Sherif M Elsharkawy

Abstract readComparative Study
In one paragraph

Article in BMC oral health, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Shaimaa OmarFixed Prosthodontics department, Faculty of Dentistry, Tanta University, Tanta, 31773, Egypt. Shaimaa_omar@dent.tanta.edu.eg.
Enas A ElshenawyDental Biomaterials department, Faculty of Dentistry, Tanta University, Tanta, 31773, Egypt.
Sherif M ElsharkawyFixed Prosthodontics department, Faculty of Dentistry, Tanta University, Tanta, 31773, Egypt.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAchieving optimal marginal accuracy is a critical factor in the long-term success of implant-supported crowns. The purpose of this study was to evaluate and compare the marginal gap of implant-supported novel hybrid nanoceramic crowns, Nanoksa G-Plus and Nanoksa BioGuard, which are innovative due to their unique composition when manufactured using two distinct digital workflows—milling and 3D printing—to determine which technique provides superior precision for this new class of restorative materials.

methodsTwenty implant fixtures were embedded into epoxy resin blocks. Stock straight titanium abutment was screwed to each fixture according to manufacturer recommendations. The samples were divided into 2 groups according to the technique of fabrication of Nanoksa hybrid nanoceramic crowns (n = 10/group). Group I subtractive technique using Nanoksa G Plus discs and group II additive technique using Nanoksa BioGuard. Stock abutments were scanned using a laboratory scanner, the crowns were fabricated and cemented with resin cement after pretreatment of all crowns according to manufacturer recommendation. Using a stereomicroscope (35X), the marginal gaps were assessed both prior to cementation and following thermomechanical accelerated aging. Mean values were calculated, and differences between groups were tested for statistical significance using paired t-test and Student t-test. A value of (P < 0.05) was considered statistically significant.

resultsSignificant differences were detected in the marginal gaps between the groups. Before cementation and following thermomechanical accelerated aging, 3D printing crowns showed a statistically significant larger marginal gap distance (59.71 and 63.83 μm, respectively) than the milled one (34.08 and 37.76 μm).

conclusionThe milling technique demonstrated significantly lower discrepancy values compared to additive technique, indicating superior marginal fit for Nanoksa hybrid nanoceramic crowns. Clinically, these findings suggest that utilizing milling for these restorations may enhance long-term outcomes by reducing the risks associated with larger gaps.

Indexed as

CeramicsCrownsDental Marginal AdaptationDental Prosthesis DesignDental Prosthesis, Implant-SupportedComputer-Aided DesignHumansPrinting, Three-DimensionalAdditive manufacturingAgingComputer aided designComputer aided manufacturingDental materialsDental prosthesis

Identifiers

PMID41629929
PMCPMC12947500

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.