Evaluation of the effect of gingival retraction with laser and retraction cord on marginal adaptation and gingival recession in full ceramic crowns for first premolar of maxilla – a clinical trial study

Evaluation of the effect of gingival retraction with laser and retraction cord on marginal adaptation and gingival recession

Clinical trial, with parallel groups, one-way blind, randomized, on 20 patients. Randomization with Excel software was used.

Patients are visited in the dental office. Part of the work is done in the research center laboratory.

entry conditions: Good general health(The patient has no systemic disease that can affect clinical outcomes) Periodontal health(Plaque index and BOP should be below 20% before prosthetic treatment) There is a good keratinized gum around the abutment tooth (gingival biotype is thick). It should not have obvious signs and symptoms of bruxism or clenching abutment teeth need reconstruction Non-living abutment teeth that have a positive long-term prognosis based on clinical evaluations and radiology Have sufficient periodontal support teeth for single-unit restoration and also have a minimum of looseness The teeth have sufficient preparation length to ensure retention and resistance shapes The patient is willing to participate in our study and sign the consent form. No entry conditions: The patient is unwilling or unable to observe adequate oral hygiene (index plate and BOP should be below 20%). Basic teeth have clinical signs. Have loose teeth of second or more degrees. Teeth need periodontal surgery before preparing the veneer. Parafunctional habits Periodontitis, severe gingivitis, poor oral hygiene and high caries activity

In this study, patients with the condition are divided into two groups; in the first group, gingival retraction is performed with cord and in the second group, diode laser retraction is performed.

The main outcome is marginal adaptation of restoration and the secondary outcome is gingival recession.

A table of random numbers is used for randomization. In Excel software environment, four-digit codes are generated using the RANDBETWEEN command. Each patient is assigned a 4-digit code. If the end digit to the right of the code is 1, 2, 5, 7, 9, the patient is in the yarn group, and if the final digit is 0, 3, 4, 6, 8, the patient is in the group. The laser is placed. All codes are recorded on paper and stored in specific envelopes. The envelopes are arranged randomly and the responsible secretary who is aware of the objectives of the study will give them one of these envelopes before entering the doctor's room when reviewing the criteria for entering the study and recording patient information. The secretary is not aware of the study hypothesis and is not aware of the details of the codes for assigning to groups. The doctor will decide on the treatment process for the patient based on the specified code. Random sequencing is performed by a statistical and epidemiological consultant using Excel software. Registration and evaluation of inclusion criteria is done by the secretary. The secretary has no information about the study hypothesis or the group code. Assignment of intervention is also done by the doctor. The doctor is aware of the group codes. The outcome assessor also has no information about how patients are coded.

Due to the nature of the intervention, it is not possible to blind patients and only the outcome assessor is unaware of the assignment of individuals to groups. Outcome assessment will be performed by a prosthetist other than the attending physician (evaluator).