MC and AC CFIDPs presented with veneer fractures as primary complication. This may require significant maintenance. Other complications were negligible after a mean follow-up period of at least 5 years. More long-term studies, especially on all-ceramic CFIDPs are needed.

The objective of this review was to assess the prevalence of antibiotic resistance genes in the oral cavity and identify mobile genetic elements (MGEs) important in disseminating them. Additionally, to assess if age, geographic location, oral site, bacterial strains and oral disease influence the prevalence of these genes. Three electronic databases (Medline, Embase and the Cochrane Library) were used to search the literature. Journals and the grey literature were also hand searched. English language studies from January 2000 to November 2020 were selected. Primary screening was performed on the titles and abstracts of 1509 articles generated. One hundred and forty‐seven full texts were obtained to conduct the second screening with strict inclusion and exclusion criteria. Forty‐four final articles agreed with the inclusion criteria. Half of the studies were classed as low quality. tet(M) was the most prevalent gene overall and the conjugative transposon Tn916 the most common MGE associated with antibiotic resistance genes in the oral cavity. In babies delivered vaginally, tet(M) was more prevalent, whilst tet(Q) was more prevalent in those delivered by C‐section. Generally, countries with higher consumption of antibiotics had higher numbers of antibiotic resistance genes. Agricultural as well as medical use of antibiotics in a country should always be considered. Between healthy, periodontitis and peri‐implantitis subjects, there was no difference in the prevalence of tet(M); however, erm(B), tet(M) and tet(O) were higher in carious active children than the non‐carious group. Subjects with poor oral hygiene have more pathogenic bacteria that carry resistance genes compared to those with good oral hygiene. Enterococcus faecalis isolates demonstrated significant tetracycline resistance (tet(M) up to 60% prevalence in samples) and erythromycin resistance (erm(B) up to 61.9% prevalence in samples), periodontal pathogens showed significant beta‐lactam resistance with blaZ and cfxA present in up to 90%–97% of samples and the normal oral flora had a high level of erythromycin resistance with mef(A/E) present in 65% of Streptococcus salivarius isolates. The most common resistance gene was tet(M) in root canals, cfxA in subgingival plaque, erm(B) in supragingival plaque and tet(W) in 100% of whole saliva samples. The review highlights that although many studies in this area have been performed, 50% were classed as low quality. We advise the following recommendations to allow firm conclusions to be drawn from future work: the use of large sample sizes, investigate a broad range of antibiotic resistance genes, improved methodologies and reporting to improve the quality of genetic testing in microbiology and randomisation of subject selection.

Purpose To ascertain whether the compatibility of non‐original abutments (NOAs) with dental implants is influenced by the type of implant connection, i.e.‐ internal or external, and whether certain combinations of componentry may be as compatible as the original components. Methods A structured literature search was conducted using 3 electronic databases (MEDLINE®, The Cochrane Library, and Web of Science Core Collection) for studies reporting on the use of non‐original abutments published between 1995 and 2020. This was supplemented with hand searching in relevant journals and references, as well as searching grey literature. Relevant studies were selected according to specific inclusion criteria. Data was collected for the following parameters: precision of fit, microleakage, micromorphological differences, micromotion, rotational misfit, screw loosening, maximum load capacity, fracture resistance, tensile strength, compressive strength and invivo implant and prosthesis outcomes. Results The electronic search and hand search yielded titles and abstracts of 5617 studies following de‐duplication; based on the eligibility criteria, 40 studies were finally selected. Overall, original abutments showed better precision of fit, ability to resist microleakage, prevention of rotational misfit and micromotion, and fatigue strength compared with non‐original abutments. Some non‐original abutments on external connections were comparable with original abutments in terms of precision of fit and resistance to screw loosening and may be associated with less catastrophic failures than those on internal connections. Conclusion Original abutments present more predictable outcomes than non‐original abutments with regards to the parameters investigated. However, it seems that external connections can provide some level of compatibility in terms of precision of fit and may also exhibit less catastrophic failures than NOAs on internal connections. This may be due to the increased rotational freedom external connections provide. There is a lack of information regarding the influence of connection geometry on many aspects of compatibility and therefore the current clinical recommendation should be to use original abutments. More laboratory studies comparing non‐original abutments on different implant connections are required. In addition, there is a need for long‐term in vivo studies providing data on the clinical performance of non‐original abutments.