Skip to content

Clinical Efficacy of Angulated Screw-retained and Cemented Single Implant Crowns in Esthetic Region

Comparison of the Short-term Clinical Efficacy of Angulated Screw-retained and Cemented Single Implant Crowns in Esthetic Region: A Randomized Controlled Clinical Trial

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04539912
Enrollment
60
Registered
2020-09-07
Start date
2018-08-01
Completion date
2020-08-01
Last updated
2020-09-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Angulated Screw-retained, Esthetics

Brief summary

Objective: To compare the clinical efficacy of angulated screw-retained and cemented single implant crowns(SIC) in esthetic region. Methods/Design: The study was a prospective, single center, randomized controlled clinical trial. Patients with the needs of single tooth restoration in esthetics region were recruited from Oct. 2018 to Aug. 2019. Sixty patients were enrolled in the present study and they were randomly assigned into two groups: angulated screw-retained group(AG, 30 patients) and cemented group (CG,30 patients). Clinical and radiological evaluations were performed on the day of final crowns delivery and 12 months later. Implant survival rate, marginal bone loss(MBL), pro-inflammatory cytokinesin peri-implant crevicular fluid (PICF)(TNF-α, IL-6), mechanical complications, peri-implant conditions(mPI, PD, BOP%), pink esthetics score/white esthetics score (PES/ WES) and patients satisfaction were assessed.

Interventions

DEVICEangulated screw retained crown

ASC abutment was used in AG;

DEVICEcemented crown

prefabricated Ti abutment was used in CG

Sponsors

Junyu Shi
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* 1\) age≥18; * 2\) Single dental implant in the esthetic region; * 3\) adjacent to natural teeth; * 4\) absence of oral mucosal disease and oral infection; * 5)implants withconical connection (Nobel Active, Nobel Biocare® or NobelReplace Conical Connection, Nobel Biocare®); * 6)patients with the willingness of all-ceramic permanent restorations.

Exclusion criteria

* 1)Multiple implants in the esthetic region, or the restoration is a bridge; * 2)Heavy smokers (\>10 cigarettes/day); * 3\) the angle between implant axis and restoration axis\>25°; * 4\) uncontrolled periodontitis; * 5\) with systematic diseases that may affect implant therapy, such as uncontrolled diabetes mellitus (Fasting blood-glucose\>7.2mmol/L, Glycosylated hemoglobin \>7%), current intake of bisphosphonates (treatment for malignancy), pregnant(or plan to get pregnant), with history of radiation therapy in head and neck region; * 6\) Unwilling to participate in the present study.

Design outcomes

Primary

MeasureTime frameDescription
Marginal bone loss1yearPeri-apical radiographs with paralleling technique wereperformed on the day offinal restorations delivery and 1-year visit. Implant length was used as calibration reference. The distance between restoration margin and the most coronal level of implant-bone contactwas recorded. Final result was calculated as themean value of the mesial and distal sites

Secondary

MeasureTime frameDescription
Pro-inflammatory cytokinesin peri-implant crevicular fluid (PICF)1 yearwe collected the patients' PICF with the paper strip (PerioPaper Strips; Oraflow Inc., Smithtown, NY, USA) at 1year follow-up to access differences in pro-inflammatory cytokines (IL-6 and TNF-α) between two groups.
Mechanical complications1 yearAbutments or implants fracture and screw loosening or fracture
pocket probing depth(PD)1 yearThe depth of 6 sites(mesial, middle and distal of buccal/lingual ) was measured and the average value was calculated.
Survival rate.1 yearSurvival rates were defined as the percentage of success implants and remained crowns which never been replaced
Patient's satisfaction1 yearpatient's satisfaction(PS) with aesthetics, function and comfort of the restoration at 1-year visit. 0 score was extremely dissatisfied and 10 score was extremely satisfied. We also defined the final scores as perfect rate(PS≥9), acceptable rate(9\>PS≥6) and unfavorable rate (PS\<6).
bleeding on probing% (BOP%)1 yearThe BOP of 6 sites(mesial, middle and distal of buccal/lingual ) was probed and the percentage of BOP(+) was calculated.
modified plaque index (mPI)1 yearScore 0; No detection of plaque Score 1: Plaque only recognized by running a probe across the smooth marginal surface of the implant. Implants covered by titanium spray in this area always score 1. Score 2: Plaque can be seen by the naked eye. Score 3: Abundance of soft matter.
PES/WES1 yearspecific dentists were asked to give scores for variables of PES (Mesial papilla, distal papilla, level of soft-tissue margin, soft-tissue contour, alveolar process and soft-tissue color and texture) and WES (Tooth form, tooth volume/outline, color, surface texture and transparency) with the 2-1-0 scoring system. Final PES/WES was the sum the two. Total scores were defined as perfect rate (PES/WES≥22), acceptable rate (22\>PES/WES≥15) and unfavorable rate (PES/WES\<15).

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026