The Use of Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) Technology for Zirconia Crowns After Laser-Assisted Crown Lengthening and Retraction: A Case Report.

Maintenance of biological width serves as a primary factor in periodontal-restorative relationships. Crown lengthening (CL) is a technique to prevent violation of biological width, with the laser method offering the advantage of surgical and patient-related outcomes. Laser CL with retraction helps with the excision of tissues, increasing the CL, maintaining the gingival contour with adequate exposure to the finish line to record the tooth preparation features. This helps to achieve the functional and esthetic outcomes essential for restorative dentistry. The marginal fit, contour, and adaptation of the crown can be further enhanced by computer-aided design and computer-aided manufacturing (CAD/CAM) technology improving patient and clinical outcomes. Hence, this case report aims to indulge the laser-assisted procedures and CAD/CAM technology to fabricate and deliver a zirconia crown maintaining the periodontal-restorative factors.

Biologic Width Following Different Crown Lengthening Procedures: A Six-Month Follow-Up Study.

BACKGROUND: One of the important things to preserve during crown lengthening is the biologic width (BW), recently called supracrestal tissue attachment. A healthy periodontium with adequate BW is very essential for the success of restored teeth. There are various techniques to perform crown lengthening procedures. Most of the studies have focused on assessing the changes in the position of the marginal gingiva and bone as outcome parameters rather than BW. Also, most of the research was done on animal models. AIM: The purpose of this study was to assess the periodontal tissue changes at three months and six months following two different surgical crown lengthening procedures. MATERIALS AND METHODS: Sixty mandibular first molars among 60 patients that required surgical crown lengthening were enrolled in the study and subjected to two different procedures, gingivectomy (Group I; n=30) and apically positioned flap with ostectomy (Group II; n=30). The following parameters were recorded at baseline, three months, and six months, position of free gingival margin (FGM), probing depth (PD), relative attachment level (RAL), bone level (BL), and BW. These measurements were made at three sites in every patient: treated tooth sites (TT), adjacent tooth's adjacent sites (AD), and adjacent tooth's non-adjacent sites (NAD). The data was then subjected to statistical analysis using SPSS software (Version 20.0). Statistical significance was set to p<0.05. RESULTS: When groups I and II were compared at three and six months, there was no statistical difference in terms of position of FGM, PD, and RAL (p>0.05). When BW was compared between the two groups at three and six months, group II showed better reestablishment of BW at any given time period and was statistically significant (p<0.05). CONCLUSION:  Following surgical crown lengthening, the bone level was shifted apically and allowed for the reestablishment of BW. At six months of follow-up, the apically positioned flap with ostectomy was superior in restoring the BW compared to gingivectomy.

Staged esthetic crown lengthening: Classification and guidelines for periodontal-restorative therapy.

OBJECTIVE: This article presents technical guidelines for perio-restorative esthetic crown lengthening, along with a discussion of the biologic rationale. A classification system is proposed to assist in treatment planning and sequencing the surgical and restorative phases. CLINICAL CONSIDERATIONS: When esthetic crown lengthening is performed as an adjunct to restorative therapy, the surgical approach must be determined by the anticipated position of the restorative margins. The removal of sufficient bone to achieve the desired clinical crown length and preserve the supracrestal gingival tissue dimensions is facilitated by the use of a surgical guide fabricated according to the design of the restorations. A staged approach allows sequencing the provisional restoration to minimize unesthetic sequelae during the healing period. Inadequate bone resection and/or alteration of the soft tissue dimensions results in delayed healing, leading to coronal gingival rebound and biologic width impingement. CONCLUSION: The identification and preservation of appropriate restorative and biologic landmarks is essential for success in pre-prosthetic esthetic crown lengthening treatment. A staged approach improves the esthetic management during the postsurgical healing and maturation period. CLINICAL SIGNIFICANCE: A restorative driven classification system for sequencing and staging adjunctive esthetic crown lengthening procedures is presented. Technical guidelines to enhance gingival margin predictability are suggested, accompanied by relevant evidence. In addition, wound healing timelines following gingival and osseous resection are provided.

Orthodontic Extrusion as an Aid for Restoring Extensively Destroyed Teeth and Preserving Implant Site Creation: A Case Series.

Preserving questionable maxillary teeth for aesthetics is challenging for many practitioners. This report presents the clinical and radiographic results of an orthodontic extrusion technique for clinical crown lengthening of female patients' maxillary teeth to increase the restorability of teeth. Splinting was carried out by using specially designed hucks cast with custom-made post joined with orthodontic brackets with adjusting teeth. Teeth were carefully extruded to the desired level without harming the marginal bone areas or root apices. Clinical follow-up evaluations were performed for 3 months before construction of the final prosthesis. Intra-oral radiographs showed normal periodontal contour consistent with new bone formation in the periapical area of all cases, with no evidence of root or crestal bone resorption or endodontic problems. This technique is highly recommended in the aesthetic area of the maxillary arch.

Gingival Biotypes and its Relation to Biologic Width, Alveolar Bone Thickness, Dehiscence and Fenestration in Mandibular Anterior Region: A CBCT Analysis Study.

Background: Gingival biotype and its relationship to biologic width and alveolar bone thickness may affect surgical periodontal therapy outcomes. Hence, it is vital to assess the gingival biotype prior to any of these treatments for its success. Aim: The study aims to compare the thick and thin gingival biotype in the mandibular anterior region concerning biologic width, buccal bone thickness, prevalence and distribution of dehiscence, and fenestration in lower anterior teeth. Materials and Methods: A total of 30 patients were selected for the study based on the inclusion and exclusion criteria. The Cone Beam Computed Tomography analysis was performed in the mandibular anterior area to assess gingival thickness (biotype), biologic width, buccal bone thickness, dehiscence, and fenestrations. The data were analyzed using SPSS version 26. An independent t-test was used to assess the relationship between the variables. Results: Our study identified an increased biologic width in the thick gingival biotype, a higher frequency of dehiscence in the thin gingival biotype than in the thick biotype, and a greater mean alveolar bone thickness in the thick biotype group. Conclusion: A statistical difference was not observed between the groups; however, the thick biotype showed better results than the thinner biotype for the periodontal parameters examined.

Gingival biotype modification with collagen matrix or autogenous subepithelial connective tissue graft: Histologic and volumetric analyses in a beagle model.

Objectives: To evaluate the volumetric effect and biocompatibility of porcine tendon-derived type I collagen matrix graft (CG) in gingival biotype modification (GBM) compared with subepithelial connective tissue graft (SCTG) in a beagle model. Methods: Surface analysis using scanning electron microscopy and a collagen degradation assay of CG was performed in vitro. Six adult dogs were used in in vivo experiment, and each received autologous SCTG or CG at the anterior side. Histometric and three-dimensional digital volume analyses were conducted to compare quantitative changes in CG and SCTG in GBM. Immunohistochemical analysis was performed for the qualitative evaluation of CG compared to SCTG. Results: CG had a double-layered structure, and its degradation was slower than that of other well-reported materials. No critical problems were associated with the healing procedure. Changes in gingival thickness and volume in the CG and SCTG groups were equivalent, with no significant differences between the groups. Type I collagen and vascular endothelial growth factor expression levels were similar in both groups. Significance: CG and SCTG had equivalent potential for GBM in terms of quantity and quality. Additionally, CG could be used as a reasonable substitute for SCTG, making surgery convenient and predicting successful clinical outcomes.

A Comparative Evaluation of Dentogingival Tissue Using Transgingival Probing and Cone-Beam Computed Tomography.

Background and Objective: Gingival biotype can be assessed using a variety of invasive and non-invasive procedures, such as direct probing, transgingival probing, ultrasound-guided approaches, and, for the more sophisticated, cone-beam computed tomography. The aim of this study was to evaluate gingival biotype in relation to transgingival probing and cone-beam computed tomography (CBCT). Materials and Methods: This study included a total of two hundred healthy individuals. Gingival thickness was assessed and measured from the right and left maxillary central incisor teeth using CBCT and transgingival probing of the attached gingiva. The measurements were analyzed with regard to tooth type (central incisor). Linear measurements for gingival biotype were measured using both methods. Correlations and differences between measurement methods were assessed. Results: The mean age of study participants was 32.49 ± 8.61 years. The radiographic measurements on CBCT were 1.34 ± 0.17 mm for the right central and 1.28 ± 0.21mm for the left central. The transgingival probing measurements were 1.31 ± 0.18 for the right central and 1.22 ± 0.21mm for the left central. Conclusion: As per the results of this study, there is a significant positive correlation between transgingival probing and CBCT measurements of gingival biotypes.

The use of the connective tissue graft from the palate for vertical soft tissue augmentation during submerged dental implant placement: A case series.

OBJECTIVES: To evaluate the efficacy of the soft tissue augmentation vertically, using connective tissue graft from the palate, during submerged dental implant placement. MATERIAL AND METHODS: Vertical soft tissue augmentation, using connective tissue graft from the palate, combining with submerged dental implant placement was performed for 50 patients (10 males and 40 females, mean age 57.22 years). Soft tissue thickness vertically was measured in the middle of the alveolar crest with the periodontal probe. After 3 months, healing abutments or multiunits were connected to the dental implants, augmented soft tissue thickness was measured vertically in the middle of the alveolar crest. The vertical soft tissue volume gain was calculated using analysis of variance descriptive analysis, significance set to p = .05. RESULTS: All 50 autogenous connective tissue grafts from the palate healed successfully. The average thickness of the soft tissue grafts from the palate was 1.8 ± 0.41 mm. After 3 months, soft tissue thickness vertically increased from 2.27 ± 0.64 mm to 4.35 ± 0.64 mm. This difference between mean figures, between the groups, before and after soft tissue augmentation was found to be statistically significant F (263;477). The mean increase in soft tissue thickness was 2.08 ± 0.71 mm. CONCLUSION: It can be concluded that soft tissue augmentation vertically, using connective tissue graft from the palate can be successfully used for vertical soft tissue augmentation.

Prosthetic restoration after atraumatic surgical extrusion: a report of two cases.

Preservation and restoration of teeth with little coronal tooth structure due to crown-root fractures or caries lesions, ensuring restoration margins do not encroach on the biologic width, constitute a challenge. Available treatment options include surgical crown lengthening and orthodontic or surgical extrusion. This report presents two patients in which teeth were restored by surgical extrusion with an atraumatic extraction system and prosthetic therapy.

An interdisciplinary approach to management of diastemas: A novel classification and a case report.

Diastema between the teeth negatively affects the patients' smile, psychology and daily activities by creating a disharmony in the patients' face. The development of diastema has been attributed to several factors such as labial frenulum, microdontia, mesiodens, peg-shaped lateral incisors, agenesis, cysts, habits such as finger sucking, tongue thrusting, or lip sucking, dental malformations, genetics, proclinations, dental-skeletal discrepancies, and imperfect coalescence of interdental septum. Patients often present with complex problems that require a multidisciplinary treatment approach which includes determination of the aetiological factors, soft tissue morphology, occlusion, patient demands and aesthetic consideration to achieve satisfactory outcomes. Lack of current literature on classification of diastemas and multi-disciplinary approach of management led to the proposal of a new classification the ATAC (Anatomic and Therapeutic Classification) for management of the diastema. This case report highlights the use of the proposed classification for management of diastemas, requiring a perio-restorative intervention using a Chu's proportion gauge to achieve ideal aesthetics.

The influence of laser-microgrooved implant and abutment surfaces on mean crestal bone levels and peri-implant soft tissue healing: a 3-year longitudinal randomized controlled clinical trial.

PURPOSE: The study aimed to compare clinical and radiographic parameters of peri-implant site of laser-microgrooved implants with either laser-microgrooved or regular machined prosthetic abutment post 3 years of early loading. METHOD: Twenty edentulous sites of systemically and periodontally healthy individuals were allocated into two groups in this prospective, two-armed, randomized double-blinded clinical trial in 1:1 ratio, wherein each site received laser-microgrooved implants with either laser-microgrooved or machined prosthetic abutments. Outcome measures included full-mouth plaque (FMPS%) and bleeding score (FMBS%), site-specific plaque (SPS%) and bleeding score (SBS%), peri-implant sulcus depth (PISD mm), and mean crestal bone loss (MCBL mm) evaluated at baseline (6 weeks), 1 and 3 years post-early loading. Mean and standard deviation of all parameters were estimated, between groups and at different time points using independent and paired t-test, respectively, Normality was checked using Kolmogorov-Smirnov test and Shapiro-Wilk test, P value ≤ 0.05 was considered as statistically significant. RESULTS: Three-year follow-up of test group showed statistically significant reduction in SPS, SBS, PISD (P value ≤ 0.001). The MCBL reduced from 1.93 mm to 0.61 mm (P value ≤ 0.001); in other words, a bone gain of 0.15 mm was obtained in the test group. CONCLUSION: Within the limitations of the present study, laser-microgrooved implants loaded with laser-microgrooved prosthetic abutments showed superior results clinically and radiographically when compared to loading with machined abutments.

Surgical extrusion: A reliable alternative for saving fractured anterior teeth.

Crown-lengthening procedures are necessary to rehabilitate supracrestal insertion tissue and to guarantee a suitable dental restoration. The objective of this article was to report a surgical extrusion procedure as a treatment option for a fractured anterior tooth. A 24-year-old male patient presented to our department to rehabilitate his maxillary right lateral incisor. The tooth was fractured due to a trauma and presented a healthy periodontium. Endodontic treatment was performed before the surgical extrusion. A fixed crown was cemented after complete reduction of tooth mobility after 6 months. No complication was observed at 6 months post-operatively. A minimally traumatic surgical extrusion technique provided highly successful results in both functional and esthetic aspects, especially in the anterior region, where the latter is of great interest.

Soft Tissue Interface with Various Kinds of Implant Abutment Materials.

Various materials, such as titanium, zirconia and platinum-gold (Pt-Au) alloy, have been utilized for dental implant trans-mucosal parts. However, biological understanding of soft tissue reaction toward these materials is limited. The aim of this study was to compare the response of cell lines and soft tissue to titanium, zirconia and Pt-Au substrata. The surface hydroxyl groups and protein adsorption capacities of the substrata were measured. Next, gingival epithelial-like cells (Sa3) and fibroblastic cells (NIH3T3) were cultured on the materials, and initial cell attachment was measured. Immuno-fluorescent staining of cell adhesion molecules and cytoskeletal proteins was also performed. In the rat model, experimental implants constructed from various materials were inserted into the maxillary tooth extraction socket and the soft tissue was examined histologically and immunohistochemically. No significant differences among the materials were observed regarding the amount of surface hydroxyl groups and protein adsorption capacity. Significantly fewer cells of Sa3 and NIH3T3 adhered to the Pt-Au alloy compared to the other materials. The expression of cell adhesion molecules and a well-developed cytoskeleton was observed, both Sa3 and NIH3T3 on each material. In an animal model, soft tissue with supracrestal tissue attachment was observed around each material. Laminin-5 immuno-reactivity was seen in epithelia on both titanium and zirconia, but only in the bottom of epithelia on Pt-Au alloy. In conclusion, both titanium and zirconia, but not Pt-Au alloy, displayed excellent cell adhesion properties.

Soft tissue integration of different abutment surfaces: An experimental study with histological analysis.

OBJECTIVE: To evaluate whether abutment surface and surface bio-activation have an effect on soft tissue morphogenesis. MATERIALS AND METHODS: 36 patients (36 implants) were included. Abutments were randomly divided into 4 groups (n = 9): Smooth Surface-MAChined (MAC), Ultrathin Threaded Microsurface (UTM), MAC Plasma of Argon activated (Plasma-MAC), and UTM Plasma of Argon activated (Plasma-UTM). After 2 months of healing, soft tissue samples were collected and prepared for histological analysis. The margin of the peri-implant mucosa (PM), the apical extension of the barrier epithelium (aJE), and the apical location of the abutment (AM) were identified. Significances of differences among groups were tested by means of the Kruskal-Wallis test and between pairs of results by means of the Mann-Whitney test. RESULTS: The mean (SD) vertical dimension of the mucosa was 2.5mm (1.0), including a connective tissue portion (CTP) of 0.8mm (0.8) in the MAC group; 3.6mm (0.2) with a CTP of 1.6mm (0.4) in the Plasma-MAC group; 3.2mm (1.0), with a CPT of 0.5mm (0.6) in the UTM; and 3.3mm (0.8), with a CPT of 0.9mm (0.7) in the Plasma-UTM group. Statistically significant differences were observed in the aJE-AM height and PM-aJE profile among the four experimental groups (p = .042 and p = .039, respectively). The Mann-Whitney test indicated differences between the Plasma-abutments and the untreated abutments both for PM-AM (p = .025) and AjE-AM (p = .021). The differences appeared more evident when the preoperative soft tissue thickness was ≤2mm. CONCLUSIONS: Within its limits, the study demonstrated a favorable effect of the plasma treatment on the connective tissue portion tissues. Plasma-MAC group highlighted the best performance. This behavior appeared strictly correlated with the soft tissue thickness.

The Relationships Between Tooth-Supported Fixed Dental Prostheses and Restorations and the Periodontium.

PURPOSE: To search the literature and to critically evaluate the findings on the periodontal outcomes of restorations and tooth-supported fixed prostheses. MATERIALS AND METHODS: PubMed was searched according to a systematic methodology, previously reported, but updated to include a larger database. Filters applied were: Case reports, clinical trial, review, guideline, randomized controlled trial, meta-analysis, systematic reviews, and English. A narrative review was then synthesized to discuss periodontal outcomes related to restorations and tooth-supported fixed prostheses. Relevant data was organized into four sections: Direct restorations, indirect restorations, biologic width or supracrestal tissue attachment and tooth preparation/finish line design. RESULTS: While increased gingival index, bleeding on probing, probing depth and clinical attachment loss have been associated with subgingival restorations, intracrevicular margins do not cause periodontal diseases. Inflammation and bone loss occur, for both direct and indirect restorations, only with large overhangs. Different restorative materials are associated with different clinical responses when placed in the gingival sulcus or within the epithelial and connective tissue attachments. When the connective tissue attachment is removed, histological changes occur causing its apical shift and subsequent re-establishment. Gingival displacement during impression procedures can cause gingival recession. Emergence profile can have a range of values, not associated with periodontal diseases. Periodontal response appears to be clinically not different when compared among different finish line designs. CONCLUSIONS: Contemporary procedures and materials used for the placement and fabrication of tooth-supported restorations and fixed prostheses are compatible with periodontal health when adequate patient education and motivation in self-performed oral hygiene are present. Periodontal diagnostic criteria should be thoroughly reviewed before fixed restorative treatments are planned and executed.

Clinical and radiographic evaluation of the Periodontium with biologic width invasion.

BACKGROUND: The biologic width is defined as the coronal dimension to the alveolar bone that is occupied by healthy gingival tissue. The objective of the present study was to correlate radiographic findings of biologic width invasion with the periodontium status. METHODS: It were included 14 patients with restored teeth with biological width invasion, on the proximal sites, observed clinically and radiographically. 122 proximal sites were evaluated, 61 in the test group (biological width invasion) and 61 in the control group (adequate biological width). Smokers and patients presenting periodontal disease or restorations with contact in eccentric movements, horizontal over-contour or secondary caries were excluded from the sample. The invasion of the biologic width was diagnosed when the distance from the gingival margin of restoration to the bony crest was less than 3 mm. Intrabony defect and bone crest level, as well as, their vertical and horizontal components were radiographically evaluated when present. Plaque index, bleeding on probing, probing depth, gingival recession height, keratinized gingival height and thickness, and clinical attachment level were clinically evaluated. Data were subjected to Spearman's Correlation and Wilcoxon's test. RESULT: The most prevalent tooth with biological width invasion was the first molar. There was a statistically significant correlation between the bone crest (p < 0.001), vertical (p < 0.001) and horizontal (p = 0.001) components. In the test group, there was a statistically significant correlation between bleeding on probing (p < 0.001; r = 0.618) and width of gingival recession (p = 0.030; r = - 0.602) with the intraosseous component; and between keratinized gingival height and bone level (p = 0.037; r = - 0.267). In the control group, there was a correlation between plaque index (p = 0.027; r = - 0.283) with bone level and correlation between keratinized gingival thickness and bone level (p = 0.034; r = - 0.273) and intrabony component (p = 0.042; r = 0.226). CONCLUSION: A statistically significant relationship was found between bleeding on probing and gingival recession in patients who presented intrabony defects due to the invasion of biological width, which may be also related to the thickness of the keratinized gingiva.

Transgingival implants with a convergent collar (PRAMA); surgical and screwed prosthetic approach. A case report.

This article presents a case report of transmucosal implant with a convergent collar (PRAMA) inserted in the anterior maxillary esthetic area. The purpose of this study is to evaluate soft and hard tissue after 12 months. One implant was placed in the esthetic area. The implant was immediately loaded with a screwed provisional prosthesis. After 3 months the definitive screwed prosthesis was inserted. The patient was reassessed 12 months post-implant placement, and during the examination, the soft-tissue texture, color, and amount of keratinized tissue was checked. No statistically significant horizontal dimensional changes of the alveolar ridge were observed between each time-point. Mean soft tissue levels significantly improved between base-line and 12 months. The reduced buccal width of the transmucosal component gives more space to the gingival thickness and promotes stability and give a better seal. The use of transmucosal implant creates a shift of the inflammatory cell infiltrate away from the crestal bone level.

Advances in implant therapy in North America: Improved outcomes and application in the compromised dentition.

Advances in dental implant therapy have strengthened our understanding of the management of the implant-soft tissue interface, with site-specific implications ranging from marginal tissue management and esthetics to immediate placement and restoration, and extend to patient-level implications of systemic conditions. The advancements in implant therapy have placed an increased emphasis on patient-centered outcomes. In this paper, the following conclusions can be drawn: improvements in both esthetics and long-term maintenance have been guided by the study of the marginal peri-implant tissues leading to innovations in implant design along the implant-abutment interface. Patient expectations for simple and realistic time intervals for treatment have promoted the use of immediate implant placement and restoration. The expansion of implant therapy offers implant options for patients with medical conditions, with one in particular, diabetes mellitus a focus of this paper. Studies on patients with diabetes are supporting the development of evidence-based treatment considerations with broader application and greater benefits for the use of implant therapy across a larger patient population. This paper is not intended to offer a comprehensive review, but offers a representative review of some of the many contributions of USA and North American clinicians to the global scientific dialogue that has guided the development of dental implant therapy.

Effect of patient- and surgery-related factors on supracrestal tissue reestablishment after crown lengthening procedure.

OBJECTIVES: The standard application of a mean value of 2.04 mm for the biologic width has been demonstrated to result in inconsistent amounts of tooth extension following a crown lengthening procedure. Biologic width has been replaced by the supracrestal gingival tissue dimension, which includes the biologic width and sulcular depth. The question whether supracrestal gingival tissue dimension established at tissue maturation following a crown lengthening procedure is not significantly different from the presurgical dimension has not been fully answered. The primary objectives of the present prospective clinical study were to compare the preoperative and the 24-week dimensions of supracrestal gingival tissue following a crown lengthening procedure and assess the alterations in gingival margin position. A secondary objective was to assess selected patient- and surgery-related factors on supracrestal gingival tissue reestablishment. METHOD AND MATERIALS: Twenty adult systemically healthy patients requiring a crown lengthening procedure were recruited for the study. A crown lengthening procedure was performed at 33 teeth and the patients were followed up to 24 weeks. The following parameters were recorded using customized stents for measurement reproducibility: stent-gingival margin (baseline, immediately after surgery, and at 6, 12, and 24 weeks), stent-bottom of sulcus (baseline and at 6, 12, and 24 weeks), stent-bone crest (baseline, at completion of osseous resection, and at 24 weeks), bone thickness (baseline, postsurgery), buccal gingival thickness (baseline, 24 weeks), and radiographic interproximal bone width (baseline, 24 weeks). Supracrestal gingival tissue, crown extension, and distance between the immediate postoperative position of the gingival margin relative to the contoured bone crest (F) were calculated. RESULTS: There were no statistically significant differences between supracrestal gingival tissue measurements at baseline and at 24 weeks for any of the four tooth sides. Crown extension remained significantly increased at 24 weeks compared to baseline for all sides, with the largest amounts of gingival creeping mesially and distally. A highly significant positive correlation (r = 0.97, P < .001) was demonstrated between flap positioning and stability of the gingival margin during the healing period. The closer was the F measurement to baseline supracrestal gingival tissue dimension, the less change in gingival margin was observed. CONCLUSIONS: The preliminary results of this investigation suggest the following: The presurgical supracrestal gingival tissue dimension can be used as a guideline measurement in crown lengthening procedures as it is reestablished with a similar apico-coronal dimension 24 weeks postoperatively; and crown extension is stable when the distance between the sutured gingival margin and the contoured osseous crest is similar to the preoperative supracrestal gingival tissue dimension.

Observation and determination of periodontal tissue profile using optical coherence tomography.

BACKGROUND AND OBJECTIVE: Diagnosis is a crucial step in periodontal treatment. The aim of this study was to evaluate the effectiveness of optical coherence tomography (OCT) for observation and determination of periodontal tissue profiles in vivo. MATERIAL AND METHODS: In experiment 1, refractive indices of purified water, porcine gingiva and human gingiva at 1330 nm were determined for the analysis of OCT images of periodontal tissues. In experiment 2, OCT examination was performed in the midlabial apico-coronal plane of mandibular anteriors in 30 Asian volunteers with healthy gingiva. Sulcus depth was measured on intra-oral photographs taken during probing. In the OCT images, the gingival, epithelial and connective tissue thickness, and the position of alveolar bone crest were determined and finally, the biologic width was measured. RESULTS: Refractive indices of purified water, porcine gingiva and human gingiva were 1.335, 1.393 and 1.397, respectively. Cross-sectional images of gingival epithelium, connective tissue and alveolar bone were depicted in real-time. The sulcular and junctional epithelium could be visualized occasionally. Laser penetration and reflection were limited to a certain depth with an approximate maximal imaging depth capability of 1.5 mm and OCT images of the periodontal structure were not clear in some cases. The average maximal thickness of gingiva and epithelium and biologic width at the mandibular anteriors were 1.06 ± 0.21, 0.49 ± 0.15 and 2.09 ± 0.60 mm, respectively. CONCLUSION: OCT has promise for non-invasive observation of the periodontal tissue profile in detail and measurement of internal periodontal structures including biologic width in the anterior region.