Patients will be recruited in periodontic department faculty of dentistry Cairo university.~Patients who already need esthetic rehabilitation treatment (implant placement, restorative treatments, periodontal therapy, and root coverage) on anterior maxilla and this treatment needs to investigate the gingival biotype.~Medical history will be taken.~Oral examination will be done.~Full mouth periodontal examination and charting will be done for each patient.~The investigation will be explained to the patient.~All the investigations will be carried out by one investigator.~Dental patients will be received to the clinic (for esthetic rehabilitation treatment such as implant placement, restorative treatments, periodontal therapy, and root coverage on anterior maxilla).~Patients who needs treatment will be investigated the gingival biotype by the five measurement methods (PT, TP, CBCT, IDS and EDS).~Patients refusing to participate will be reported with the cause of their refusal.~Conventional clinical examination will be held on a dental unit using the light of the unit, mirror and probe.~Before the investigation, the aim of the study will be explained to the patient and the patient's acceptance to participate in the survey will be obtained.~Periodontal status will be evaluated including assessment of gingival index (GI), plaque index (PI), probing pocket depth (PPD) on aesthetic zone in maxillary teeth by using UNC 15 periodontal probe which is 15mm long probe with markings at each millimetre and colour coded at 5th,10th and 15th mm.~Then an investigator will evaluate the gingival biotype by probing Transparency (PT) as reported by (Kan et al., 2010). The periodontal probe will be softly inserted into the gingival sulcus till it reaches the sound bone on the labial side of the maxil¬lary anterior teeth and it will be parallel to the long axis of the crown. The gingival biotype will be considered as thick if the probe tip is not seen into the tissue and it will be considered as thin if the probe was seen. If the thick en d of the probe was seen into the tissue but the thin end was not, then it will be considered as a moderate biotype.~The second method of assessment to the gingival biotype will be carried out using CBCT with lip retraction. It is important to note that the patients will not receive additional radiation exposure for the purpose of this investigation and to give us clear details about soft tissue, patients have already underwent CBCT examination as an investigation method for aesthetic rehabilitation treatment.~Afterwards, gingival biotype assessment will be done by intraoral digital examination (Kim et al., 2016). This is the third method; the investigation of gingival biotype of the anterior maxilla will be done by means of a three-dimensional intraoral scanner. The intraoral scanning data will be acquired in stereolithogra¬phy (STL) format and will be matched with the CBCT data. Three highly radiopaque and relatively fixed positions in the teeth will be chosen as fiducially markers to match the STL files with the CBCT images in accordance with a best-fit algorithm using TRIOS software (3Shape).~Finally, the fourth method for gingival biotype investigation will be performed by extraoral digital scanning (EDS) of a gypsum cast of the maxillary teeth, then the classic alginate impression of the max-illary arch and cast with dental stone will be made, gyp¬sum cast will be scanned using a three-dimen-sional scanner, and the STL data will be matched with the CBCT image according to a best-fit algorithm as in intraoral method.~Assessment of some anatomic parameters (crown width/crown length ratio, attached gingival width, labial bone thickness and papilla volume) will also be performed.
The study is a Diagnostic accuracy study that determining the accuracy of assessing the gingival biotype and some other anatomic parameters,including (crown width / crown length ratio, attached gingival width, labial bone thickness and papilla volume) by different methods :1- probe transparency, 2-transgingival probing, 3-cone beam computed tomography, 4-intraoral digital scanning, 5-extraoral digital scanning