Limited Tooth StructureNCT07259187
Retrospective Analysis of Complications and Survival of Teeth Restored Following Crown Lengthening
An observational study of Limited Tooth Structure and Crown Lengthening, run by Mohammed Bin Rashid University of Medicine and Health Sciences at 1 site in United Arab Emirates.
Trial summary
The ultimate goal for every dental restoration is to restore and maintain the dentition's functionality along with preserving periodontal support. The long-term success of a restored tooth depends on the retention of a healthy periodontium. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Limited Tooth Structure, Crown Lengthening
- What is being tested?
- Periapical radiograph
- How many people
- 81 participants
- Where
- 1 siteUnited Arab Emirates
- Study dates
- 22 Mar 2022to 30 Jun 2023
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients were included if both the CLP and crown placement procedures were performed by postgraduate residents in periodontology and prosthodontics departments, respectively, at X hospital. All patients aged between 18 and 70 years at the time of treatment, and for whom at least one year had elapsed since definitive crown placement
Inclusion Criteria: Patients were included in the study if they met all the following conditions:
- Setting and Providers: The tooth received crown lengthening surgery (CLP) performed by postgraduate residents in Periodontology and subsequent definitive crown placement by postgraduate residents in Prosthodontics at X Hospital.
- Patient Characteristics:
Age between 18 and 70 years at the time of the CLP. Able and willing to participate, with written informed consent obtained.
- Follow-up and Documentation Requirements: A minimum of 12 months had elapsed since placement of the definitive crown at the time of data collection. Baseline intraoral radiographs available prior to CLP to document periodontal and structural condition.
- Tooth-Level Clinical Criteria: Tooth mobility not exceeding Miller Class I at baseline. A planned or anticipated crown-root ratio ≥1:1 following CLP based on clinical and radiographic evaluation.
Exclusion Criteria: Patients were excluded if any of the following conditions applied:
- Procedure Purpose or Type: CLP performed exclusively for aesthetic indications.
- Cases involving intentional endodontic treatment and CLP performed solely to correct supra-eruption for prosthetic clearance (i.e., without biological indication).
- Baseline Dental and Periodontal Condition:
Teeth exhibiting furcation involvement at baseline. Mobility greater than Miller Class I preoperatively.
- Teeth functioning as abutments for fixed dental prostheses, due to altered biomechanical loading.
- Treatment Completion and Record Accuracy:
Absence or incompleteness of clinical or radiographic documentation prior to CLP. Incomplete endodontic, periodontal, or definitive restorative treatment at the time of review.
- The final restoration was not a full-coverage definitive crown.
- Follow-up and Participant Availability:
Follow-up duration less than 12 months after crown placement. Patients who declined participation or could not be contacted for consent.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Retrospective Analysis of Complications and Survival of Teeth Restored With Single Crowns Following Crown Lengthening
The ultimate goal for every dental restoration is to restore and maintain the dentition's functionality along with preserving periodontal support. The long-term success of a restored tooth depends on the retention of a healthy periodontium. When restoring a short clinical crown, the clinician may contemplate placement of subgingival margin to gain additional length for retention purposes. Thus, crown lengthening procedure is performed to gain access to the natural tooth structure while maintaining the periodontal health and to increase the retention of the restoration. A full crown restoration is needed to protect the compromised tooth from fracture. The prognosis of these teeth depends on the long-term success rate of each component of the overall treatment and the follow up maintenance.
In order to assist dentists to make an evidence-based decision during treatment planning, this retrospective study aims to investigate the complications and survival rate of the teeth receiving crown following crown lengthening.
Read the detailed description
The aim of this retrospective study was to evaluate the survival rates and complications of structurally compromised teeth restored with full-coverage crowns following crown lengthening procedure (CLP), in a postgraduate dental setting.
In this retrospective study the records of patients who received surgical CLP prior to receiving full coverage crowns at X hospital between January 2011 to January 2021 were obtained and reviewed by A.AH and F.AR for possible inclusion in the study. Retrospective data were collected manually from digital records of registered patients (Dental4windows, Centaur Software Development Co Pty Ltd., Australia). All personal information is de-identified and securely stored with a study code number. The data were then organized into categories based on a pre-determined form for single crowns with CLP .
The calculation of sample size was based on a 10-year survival rate of 78.4% tooth preservation after crown lengthening procedure and restorative treatment in department of periodontics and oral medicine at the school of dentistry of the university of Michigan (where p is the prevalence of crown after crown lengthening, d is the precision of the estimate, and z_(α/2)^2 is the quartile of the 95% confidence interval).
Using the above equation and data from the aforementioned study, the sample size needed is determined to be 260 teeth.
Statistical Analysis The collected data will be transferred to Statistical Package for Social Sciences (SPSS) for Windows (IBM- SPSS) version 25.0 (SPSS Inc., Chicago, IL, USA) for statistical analysis.
Significance for statistical analysis will be set at P < 0.05. Chi-square analysis will be used to measure the association strength between the frequency of both the survival of crown after crown lengthening and the complications. Kaplan-Meier will be used for analysis of the survival and Logistic regression will be used for the potential risk factors. P values <0.05 will be considered as a statistically significant.
- Conditions
- Limited Tooth Structure, Crown Lengthening
- Being tested
- Periapical radiograph
- Keywords
- complications, survival rate, crown lengthening, endodontics
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Periapical radiographDiagnostic test
Clinical and radiographic examinations were completed for the treated teeth. For participants who had radiographs within past one year of examination no further radiographs were obtained. Demographic parameters, systemic and patient-related factors such as smoking, diabetes mellitus, parafunctional habits (self-reported or diagnosed bruxism and clenching), location of tooth (maxilla or mandible, anterior or posterior), history of treated periodontitis, history of endodontic treatment, and history of regular dental attendance were documented. Furthermore, periodontal status was evaluated by assessing mobility, probing pocket depth, bleeding index, plaque index, restorative margin position in relation to the gingival margin, and crown to root ratio based on periapical radiographs taken using long-cone parallel technique. In addition, prosthetic factors including crown material and opposing dentition, namely tooth, crown, or removable partial denture were recorded.
| Study group | Role | What they receive |
|---|---|---|
| single crowns post surgical crown lenghtening | Patients who underwent surgical crown lengthening prior to receiving single-crown restorations were contacted to participate in the study. The restored teeth were clinically and radiographically examined. Demographic data, patient- and tooth- related details, prevalence of prosthodontic, periodontal, and/or endodontic complications, as well as failure rate with underlying reason were documented and analyzed. Receives: Diagnostic Test: Periapical radiograph |
What is being measured
The primary outcome is the main question the study is designed to answer.
Teeth survival
tooth survival was defined as tooth remaining in situ with or without complications
Measured: 1 year or more postintervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2025
- Study start22 Mar 2022
- Primary completion31 Mar 2023
- Study completion30 Jun 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Limited Tooth StructureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 81 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mohammed Bin Rashid University of Medicine and Health Sciences
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Maanas Shah, Mohammed Bin Rashid University of Medicine and Health Sciences
- Investigators
- Maanas Shah, BDS MSD CAGS MRACDS, Principal investigator, Mohammed Bin Rashid University of Medicine and Health Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07259187
- Sponsor's protocol ID
- MBRU-IRB-2022-97
- Status last verified
- Oct 2025
- First submitted
- 19 Nov 2025
- Last updated
- 2 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: The authors have decided not to share individual participant data (IPD) because the dataset contains clinical information derived from patient records within an academic training setting, and complete anonymization cannot be fully guaranteed. In addition, institutional and ethical board policies restrict external sharing of patient-level data to protect participant confidentiality. Summary data supporting the findings of this study are available within the manuscript and supplementary materials.
Publications
Ashnagar S, Barootchi S, Ravida A, Tattan M, Wang HL, Wang CW. Long-term survival of structurally compromised tooth preserved with crown lengthening procedure and restorative treatment: A pilot retrospective analysis. J Clin Periodontol. 2019 Jul;46(7):751-757. doi: 10.1111/jcpe.13124. Epub 2019 May 31.
PubMed 31050812
Study at a glance
From the registry record, last updated by the sponsor on 2 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Retrospective Analysis of Complications and Survival of Teeth Restored With Single Crowns Following Crown Lengthening
- ClinicalTrials.gov ID
- NCT07259187
- Acronym / sponsor ID
- MBRU-IRB-2022-97
- Conditions
- Limited Tooth Structure, Crown Lengthening
- Keywords
- complications, survival rate, crown lengthening, endodontics
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 81 participants (actual)
- Lead sponsor
- Mohammed Bin Rashid University of Medicine and Health SciencesUniversity, hospital or other
- Study start
- 22 Mar 2022 (actual)
- Primary completion
- 31 Mar 2023 (actual)
- Study completion
- 30 Jun 2023 (actual)
- First posted
- 2 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The ultimate goal for every dental restoration is to restore and maintain the dentition's functionality along with preserving periodontal support. The long-term success of a restored tooth depends on the retention of a healthy periodontium. When restoring a short clinical crown, the clinician may contemplate placement of subgingival margin to gain additional length for retention purposes. Thus, crown lengthening procedure is performed to gain access to the natural tooth structure while maintaining the periodontal health and to increase the retention of the restoration. A full crown restoration is needed to protect the compromised tooth from fracture. The prognosis of these teeth depends on the long-term success rate of each component of the overall treatment and the follow up maintenance.
In order to assist dentists to make an evidence-based decision during treatment planning, this retrospective study aims to investigate the complications and survival rate of the teeth receiving crown following crown lengthening.
Detailed description
The aim of this retrospective study was to evaluate the survival rates and complications of structurally compromised teeth restored with full-coverage crowns following crown lengthening procedure (CLP), in a postgraduate dental setting.
In this retrospective study the records of patients who received surgical CLP prior to receiving full coverage crowns at X hospital between January 2011 to January 2021 were obtained and reviewed by A.AH and F.AR for possible inclusion in the study. Retrospective data were collected manually from digital records of registered patients (Dental4windows, Centaur Software Development Co Pty Ltd., Australia). All personal information is de-identified and securely stored with a study code number. The data were then organized into categories based on a pre-determined form for single crowns with CLP .
The calculation of sample size was based on a 10-year survival rate of 78.4% tooth preservation after crown lengthening procedure and restorative treatment in department of periodontics and oral medicine at the school of dentistry of the university of Michigan (where p is the prevalence of crown after crown lengthening, d is the precision of the estimate, and z_(α/2)^2 is the quartile of the 95% confidence interval).
Using the above equation and data from the aforementioned study, the sample size needed is determined to be 260 teeth.
Statistical Analysis The collected data will be transferred to Statistical Package for Social Sciences (SPSS) for Windows (IBM- SPSS) version 25.0 (SPSS Inc., Chicago, IL, USA) for statistical analysis.
Significance for statistical analysis will be set at P < 0.05. Chi-square analysis will be used to measure the association strength between the frequency of both the survival of crown after crown lengthening and the complications. Kaplan-Meier will be used for analysis of the survival and Logistic regression will be used for the potential risk factors. P values <0.05 will be considered as a statistically significant.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| single crowns post surgical crown lenghtening | – | Diagnostic Test: Periapical radiographPatients who underwent surgical crown lengthening prior to receiving single-crown restorations were contacted to participate in the study. The restored teeth were clinically and radiographically examined. Demographic data, patient- and tooth- related details, prevalence of prosthodontic, periodontal, and/or endodontic complications, as well as failure rate with underlying reason were documented and analyzed. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients were included if both the CLP and crown placement procedures were performed by postgraduate residents in periodontology and prosthodontics departments, respectively, at X hospital. All patients aged between 18 and 70 years at the time of treatment, and for whom at least one year had elapsed since definitive crown placement
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Periapical radiographClinical and radiographic examinations were completed for the treated teeth. For participants who had radiographs within past one year of examination no further radiographs were obtained. Demographic parameters, systemic and patient-related factors such as smoking, diabetes mellitus, parafunctional habits (self-reported or diagnosed bruxism and clenching), location of tooth (maxilla or mandible, anterior or posterior), history of treated periodontitis, history of endodontic treatment, and history of regular dental attendance were documented. Furthermore, periodontal status was evaluated by assessing mobility, probing pocket depth, bleeding index, plaque index, restorative margin position in relation to the gingival margin, and crown to root ratio based on periapical radiographs taken using long-cone parallel technique. In addition, prosthetic factors including crown material and opposing dentition, namely tooth, crown, or removable partial denture were recorded. | Diagnostic test | single crowns post surgical crown lenghtening |
Primary outcome
Teeth survival
Time frame: 1 year or more postintervention
tooth survival was defined as tooth remaining in situ with or without complications
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Dec 2025.
- Results publication: PubMed 31050812Ashnagar S, Barootchi S, Ravida A, Tattan M, Wang HL, Wang CW. Long-term survival of structurally compromised tooth preserved with crown lengthening procedure and restorative treatment: A pilot retrospective analysis. J Clin Periodontol. 2019 Jul;46(7):751-757. doi: 10.1111/jcpe.13124. Epub 2019 May 31.
- Individual participant dataSharing planned: Undecided. The authors have decided not to share individual participant data (IPD) because the dataset contains clinical information derived from patient records within an academic training setting, and complete anonymization cannot be fully guaranteed. In addition, institutional and ethical board policies restrict external sharing of patient-level data to protect participant confidentiality. Summary data supporting the findings of this study are available within the manuscript and supplementary materials.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Maanas Shah, BDS MSD CAGS MRACDS principal investigator
Mohammed Bin Rashid University of Medicine and Health Sciences
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Limited Tooth Structure and Crown Lengthening, run by Mohammed Bin Rashid University of Medicine and Health Sciences at 1 site in United Arab Emirates.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Arab Emirates. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Teeth survival (time frame: 1 year or more postintervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07259187, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Dec 2025.