Digital Planning and Guided Dual Technique in Aesthetic Crown Lengthening
Condition: Tooth Eruption Disorder
MeSH terms: Exanthema
Study type: Interventional

Summary: 
      Excessive gingival exposure, commonly named gingival smile, results in a dentogingival
      disharmony. One of the gingival smile treatment is the aesthetics-related crown lengthening
      surgery (ACL) to provide a adequate clinical crown length and diminish gingival display. In
      this context, digital planning and guided dual technique have been proposed to increase the
      effectiveness and predictability of the ACL. In this technique, an facial and dental analysis
      of the patient is performed and transferred to a digital model obtained by intraoral digital
      scan. The digital model is used to create a double guide that will determine the final
      position of the gingival and alveolar margin in the ACL. Despite the technique showing
      promising results, clinical studies evaluating the effectiveness of this technique are
      scarce. The present study aims to evaluate the digital planning and guided dual technique in
      the ACL in comparison to conventional technique in relation to the predictability/stability
      of the gingival margin positioning and patient satisfaction after the ACL. Twenty-four
      patients diagnosed with altered passive eruption type I subcategory B will be selected and
      divided into two groups. In the control group (n = 12) patients will be submitted to the
      conventional ACL planned using clinical examination; in the test group (n = 12) patients will
      be submitted to ACL using cone beam computed tomography (CBCT), digital planning and guided
      dual technique. Periodontal clinical parameters including probing depth (PS), clinical
      attachment level (CAL), clinical crown length (CCL), anatomical crown length (ACL) and
      cemento-enamel junction to alveolar bone crest distance will be evaluated clinically at
      baseline, in the immediate postoperative, 4, 8 and 12 months after the procedure.
      Participants will be submitted to questionnaires to assess satisfaction with the smile, gum
      and tooth characteristics and experience with the procedure. The investigators aim to
      demonstrate with the study the effectiveness of the both techniques and evaluate the clinical
      cost benefit for the patient and the dentist of the guided dual technique in relation to the
      conventional ACL technique.
    


Intervention name(s): Conventional aesthetic crown lengthening surgery; Guided dual aesthetic crown lengthening surgery
Intervention type(s): Procedure; Procedure
Intervention description(s): The demarcation of the gingival zenith final position will be done on the teeth using a periodontal probe. This demarcation will be done through visual examination based on the crown length/width ratio and the position of the cemento-enamel junction (CEJ). The gingival margin of the central and canine incisors will be positioned at similar heights and a more coronal gingival contour will be determined for the lateral incisors. An internal bevel incision will be made with a blade on each tooth, preserving the interdental papillae. The incised gingival tissue will be removed using a periodontal curette in both groups. An internal bevel incision will be made in the involved teeth and a full thickness flap will be displaced up to the the mucogingival junction level to expose the bone crest (BC). Carbide drills and manual chisels will be used for bone resection to obtained a CEJ-BC distance of 3 mm. Simple interproximal interrupted sutures will be performed.; The double guide will be positioned and an internal bevel incision on each tooth will be made following the guide demarcation. After the initial incision, the incised gingival tissue will be removed using a periodontal curette. An internal bevel incision will be made in the involved teeth and a full thickness flap will be displaced up to the the mucogingival junction level to expose the bone crest (BC). The dual guide will be positioned again and the bone tissue will be removed using carbide drills and manual chisels following the double guide. No interproximal crestal bone will be removed. Simple interproximal interrupted sutures will be performed to stabilize the flap.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Crown Lengthening; Altered passive eruption; Gingival smile