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Concept: Inlays and onlays


SUMMARY Fracture resistance of inlays and onlays may be influenced by the quantity of the dental structure removed and the restorative materials used. The purpose of this in vitro study was to evaluate the effects of two different cavity preparation designs and all-ceramic restorative materials on the fracture resistance of the tooth-restoration complex. Fifty mandibular third molar teeth were randomly divided into the following five groups: group 1: intact teeth (control); group 2: inlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent AG, Schaan, Liechtenstein); group 3: inlay preparations, zirconia ceramic (ICE Zirkon, Zirkonzahn SRL, Gais, Italy); group 4: onlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press); and group 5: onlay preparations, zirconia ceramic (ICE Zirkon). The inlay and onlay restorations were adhesively cemented with dual polymerizing resin cement (Variolink II, Ivoclar Vivadent AG). After thermal cycling (5° to 55°C × 5000 cycles), specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. Statistical analyses were performed using one-way analysis of variance and Tukey HSD tests. The fracture strength values were significantly higher in the inlay group (2646.7 ± 360.4) restored with lithium-disilicate glass-ceramic than those of the onlay group (1673.6 ± 677) restored with lithium-disilicate glass-ceramic. The fracture strength values of teeth restored with inlays using zirconia ceramic (2849 ± 328) and onlays with zirconia ceramic (2796.3 ± 337.3) were similar to those of the intact teeth (2905.3 ± 398.8). In the IPS e.max Press groups, as the preparation amount was increased (from inlay to onlay preparation), the fracture resistance was decreased. In the ICE Zirkon ceramic groups, the preparation type did not affect the fracture resistance results.

Concepts: Touring car racing, FIA, Teeth, Analysis of variance, Crown, Dental restoration, CAD/CAM Dentistry, Inlays and onlays


Aim of the study was to evaluate the long-term reliability and effectiveness of inlays and onlays in ceramic and composite material, examining scientific studies published from 2004 to 2013. The results of this review were analyzed and compared with the important literature review proposed by Manhart in 2004.

Concepts: Scientific method, Science, Composite material, Cultural studies, Dental restoration, Restorative dentistry, Inlays and onlays


Preclinical dental students must demonstrate aptitude in the preparation of teeth for treatment with several types of fixed dental prostheses. The optimal sequence of instruction and examination of these crown preparations in preclinical fixed prosthodontics is unknown. The aim of this study was to determine if grading scores by faculty and students were affected by changing the sequence of crown type preparations. Practical exams of two successive student cohorts (n=89 in 2014; n=92 in 2015) at one U.S. dental school using three crown preparations (full cast, porcelain fused to metal, and all-ceramic) in different order were analyzed by faculty grades and student self-assessment. All of the models indicated that the sequence in which the crown type preparations were taught did have an effect on the grades. The 2014 cohort had overall higher grades and particularly higher grades for the all-ceramic crown preparations. Evaluation scores were affected by the sequence in which the different crown type preparations were taught and tested. Although the overall results suggested that students may perform better if the all-ceramic crown preparation is taught last, this tendency may differ between years.

Concepts: Crown, Dental restoration, Restorative dentistry, CAD/CAM Dentistry, Bridge, Prosthodontology, Inlays and onlays, Fixed prosthodontics


Two commonly used tibial designs for unicompartmental knee arthroplasty (UKA) are all-polyethylene “inlay” and metal-backed “onlay” components. Biomechanical studies showed that the metal baseplate in onlay designs better distributes forces over the tibia but studies failed to show differences in functional outcomes between both designs at mid-term follow-up. Furthermore, no studies have compared both designs with total knee arthroplasty (TKA).

Concepts: Type I and type II errors, Knee, Knee replacement, Tibia, Inlays and onlays


To investigate the longevity and reasons for failure of posterior cast Class II gold inlays and onlays among a group of Norwegian adults. The term inlay was used for both inlays and onlays.

Concepts: Crown, Dental restoration, CAD/CAM Dentistry, Inlays and onlays


Data sourcesMedline, Embase, the Cochrane Oral Health Group’s Trials Register and CENTRAL. Unpublished literature was searched on, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. Hand searching of reference lists only.Study selectionRandomised controlled trials with a minimum of three years follow-up that compared direct to indirect inlays or onlays in posterior teeth. Primary outcome was failure (the need to replace or repair).Data extraction and synthesisTwo reviewers independently and in duplicate performed the study selection and two extracted data independently using a customised data extraction form. The unit of analysis was the restored tooth. Risk of bias was assessed using the Cochrane Risk of Bias tool. Meta-analysis was conducted on two studies using the random-effects model.ResultsThree studies were included. Across these studies there were 239 participants in whom 424 restorations were placed. Two studies compared direct and indirect inlays and had follow-up of five and 11 years respectively. One study compared direct and indirect onlays with a follow-up of five years. The studies were at unclear or high risk of bias. For direct and indirect inlays, Relative Risk (RR) of failure after five years was 1.54 (95% Cl: 0.42, 5.58; p = 0.52) in one study and, in another was 0.95 (95% Cl: 0.34, 2.63; p = 0.92) over 11 years. For onlays there was also no statistically-significant difference in survival, though overall five-year survival was 87% (95% CI: 81-93%).ConclusionsThere is insufficient evidence to favour the direct or indirect technique for the restoration of posterior teeth with inlays and onlays.

Concepts: Epidemiology, Clinical trial, Medical statistics, Relative risk,, Tooth, Thesis or dissertation, Inlays and onlays


Buccal mucosa grafts and fascio-cutaneous flaps are frequently used in long anterior urethral strictures (1). The inlay and onlay buccal mucosa grafts are easier to perform, do not need urethral mobilization and generally have good long-term results (2-4). In the present video, we present a case where we used a double buccal mucosa graft technique in a simultaneous penile and bulbar urethral stricture.

Concepts: Present, Time, Mucous membrane, Urethra, Grafting, Urethral stricture, Esophageal stricture, Inlays and onlays


Adhesive cementation is a useful procedure not only for cementing restorations onto teeth but also for attaching new ceramic restorations to existing restorations to improve their esthetics and/or function. This clinical report presents a technique for modifying an existing nonsatisfactory implant-supported fixed dental prosthesis by means of adhesively cemented veneers and onlays bonded to the pre-existing metal-ceramic surface with resin cement. This modification may avoid the replacement of the fixed dental prosthesis, reducing both treatment costs and time while fulfilling the patient’s demands.

Concepts: Prosthetics, Crown, Dental restoration, Restorative dentistry, CAD/CAM Dentistry, Imperative programming, Inlays and onlays, Self-modifying code


The aim of this paper is to present the long-term follow-up of one paediatric zirconia crown on a deciduous molar. Preformed crowns are part of the armamentarium in paediatric dentistry. In recent years, aesthetic alternatives to preformed metal crowns have been developed, first preveneered crowns and then zirconia crowns. This paper describes the restoration of a primary molar with a zirconia crown (EZ-Pedo, Loomis, California, USA) in an 8-year-old boy. In this clinical case, the protocol for the implementation and maintenance of zirconia crowns is detailed. The patient was followed up for 29 months until the natural exfoliation of his primary molar. The adaptation of the zirconia crown, the gingival health and the wear on the opposing tooth were considered. In this case, the paediatric zirconia crown allowed sustainable functional restoration while restoring a natural appearance of the tooth.

Concepts: Physician, Crown, Dental restoration, CAD/CAM Dentistry, Zirconium dioxide, Bridge, Inlays and onlays


Several evaluation systems for clinical exams have been suggested over the years, but no systematic analysis of checklists or criteria-based exam forms has yet been undertaken. The aims of this study were to analyze criteria-based evaluation forms and to identify areas in the teaching process potentially requiring improvements. All evaluation forms introduced in 2012 at the Clinic for Periodontology, Endodontology, and Cariology at the University Center of Dental Medicine in Basel, Switzerland, and applied over a three-year period (n=1,093 in 2015) were analyzed using predefined criteria. The authors investigated how well clinical tasks were examined with the given criteria and which criteria were preferably evaluated with a grading system (0-2) or a yes/no choice. The average final grades ranged from 0.89 (n=92) for gold inlay preparation to 1.76 (n=46) for periodontal treatment. Comments were made in 38.5% (n=356) of all exams, mainly highlighting specific aspects of existing criteria. Overall, 13 criteria out of 66 should be checked instead of graded. This methodological analysis of exam forms assessing tasks in operative dentistry yielded valuable information on areas with potential for improvement in the dental curriculum and the evaluation process. Aspects that require more theoretical background and/or hands-on recommendations from experienced clinicians were identified, and ways of further refining and redesigning the evaluation forms were proposed.

Concepts: Scientific method, Grade, Gingiva, Dental implant, Periodontitis, Clinic, Dentistry, Inlays and onlays