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.

Profilometric changes of peri-implant tissues over 5 years: A randomized controlled trial comparing a one- and two-piece implant system.

OBJECTIVES: To assess the profilometric changes of the buccal soft tissues between baseline and 5 years of loading using a one- and two-piece dental implant system. MATERIALS AND METHODS: Sixty patients randomly received dental implants of either a two-piece type (BRA) or a one-piece type (STM). Casts were obtained at baseline (after crown insertion), at the 1-year and at the 5-year follow-up. Stereolithography files were obtained from the casts for digital superimposition. One implant and the contralateral natural tooth were selected for the analysis. Thirty-three patients (BRA = 16; STM = 17) were included. Measurements included changes for crown height (CH) and estimated soft tissue thickness, as well as the profilometric change at the implant and the tooth site. Nonparametric methods were applied for the statistical analyses and medians and quartiles presented. RESULTS: The BRA group lost -0.39 mm and the STM group lost -0.40 mm of volume between baseline and the 5-year follow-up at the implant site (p > 0.05). The tooth site lost -0.18 mm (BRA) and -0.12 mm (STM) (p > 0.05). Volume differences between implants and teeth amounted to -0.05 mm (baseline to 1 year) and -0.25 mm (baseline to 5 years) for BRA, while for STM, the values were 0.03 mm (baseline to 1 year) and -0.16 mm (baseline to 5 years). The changes for implant CH at 1 and 5 years of follow-up amounted 0.10 and 0.09 mm (BRA) and to 0.03 and 0.22 mm (STM). The changes in tissue thickness at 1 and 5 years in the BRA group amounted to -0.28 and -0.66 mm at 1 mm, -0.21 and -0.46 mm at 3 mm, and -0.32 and -0.45 mm at 5 mm, respectively. The changes in the STM group amounted to -0.15 and -0.54 mm at 1 mm, -0.24 and -0.48 mm at 3 mm, and -0.32 and -0.57 mm at 5 mm, respectively. No significantly different medians were observed. CONCLUSIONS: Minimal profilometric and linear changes occurred at implant sites between baseline and 5 years, between implant and tooth sites and between the two implant systems.

Effects of crown movement on periodontal biotype: a digital analysis.

Orthodontic treatment has important correlations with periodontal changes. Various mechanical and biological factors are involved in determining such changes, but anatomical and morphological variables, generally addressed as periodontal biotype, play a key role. In measurement of such modifications, digital and non-contact reverse engineering technologies may be of tremendous advantage. The aim of this study is to retrospectively evaluate, in a series of digitized dental casts, some of the parameters addressing periodontal biotype and correlate them to extent and direction of tooth movement. Pre- (T0) and post-treatment (T1) dental casts of 22 patients were scanned by 3Shape TRIOS 3® scanner. A number of variables (crown ratio, gingival margin position, gingival contour, papillae position, gingival scallop) were investigated and their variations calculated after digital measurements on single casts at T0 and T1, or after direct measurement (T1 vs T0) on the superimposition and alignment of digital models. Univariate and multivariate statistics were then performed. No significant correlation was detected between the sagittal or vertical movement of dental crown and displacement of the gingival margin. On the other hand, vestibular gingival contour resulted significantly altered by vestibular and extrusion movements. Further studies are needed to ascertain the differential effect of bone and soft tissue on such modifications. The relationship between orthodontic treatment and the periodontium overcomes the consideration of gingival recession and includes all the concepts of periodontal biotype with its characteristics. Digital technologies and non-contact reverse engineering techniques now available have the potential to allow a more precise definition of such a relationship.

An Evaluation of the Effect of Periodontal Biotype on Inter-Dental Papilla Proportions, Distances Between Facial and Palatal Papillae in the Maxillary Anterior Dentition.

PURPOSE: Gingival esthetics are an essential segment of facial beauty. The aim of the present study was to clinically assess the impact of periodontal biotype (PB), the length between the base of interproximal contact area and the interproximal bone crest (CP-BC), the distance between the facial and palatal papillae (DFPP), and papillary proportions (PP) on the presence of interdental papillae (PIP). MATERIALS AND METHODS: 80 patients aged 18 to 60 years were recruited for study. PB and CP-BC were evaluated clinically. Alginate impressions of maxillary arches were made, and DFPPs were measured using a digital Vernier caliper. The impressions were later poured in dental stone, and PP were calculated. RESULTS: Descriptive statistics and ANOVA were used for statistical analysis for correlation among the variables. A greater proportion of individuals who had a thick PB (77.7%) had significantly higher amounts of PIP than did patients with thin PB (60.7%) (p < 0.01). A strong significant positive correlation was found between PIP in thick PB patients and DFPP (p < 0.01, r = 0.56); DFPP and PP (p < 0.01, r = 0.61). A strong negative correlation was seen between PIP in thin PB and DFPP (p < 0.01, r = -0.67). CONCLUSION: According to the results of this study, PB affected the heights and presence of maxillary interdental papillae by affecting papilla proportion and distances between the facial and palatal papillae.

The relationship between open versus normal contact point and inter-proximal papilla dimensions in periodontally healthy young adults: A controlled clinical trial.

AIM: The gingival architecture is determined by the spatial orientation of the gingival zenith (GZ) and the inter-dental papillae (IP). Among the factors commonly associated with the presence and morphology of the IP, the contact point (CP) and the inter-dental distance relationships have been considered the most important. The objective of the present controlled clinical trial was to evaluate the role of the CP in determining the clinical and morphometric parameters of the inter-dental papilla. MATERIALS AND METHODS: The inter-dental papillae of sixty patients with unilateral diastemas were evaluated by means of periodontal probing, transgingival probing, the papilla presence index and morphometric measurement with a digital calliper and were analysed with a paired t-test, with significance set at alpha value of 0.05 or lower. RESULTS: All the papillae exhibited PPI score = 1. Papillary measurements were significantly increased in the experimental (diastema) group. CONCLUSIONS: In patients with gingival health, the dimensions of the IP are significantly increased in teeth without a contact point in comparison with their contra-lateral controls with a contact point. The contact point does not determine the presence and size of the inter-dental papilla, in patients with a healthy gingiva and without periodontal attachment loss.

Impaired periodontium and temporomandibular joints in tumour necrosis factor-α transgenic mice.

AIM: Tumour necrosis factor (TNF)-α is a pathological factor causing the characteristic symptoms of periodontal disease and rheumatoid arthritis. In this study, we describe the phenotypes of human TNF-α transgenic mice (hTNFtg) with respect to their periodontium and the temporomandibular joint (TMJ). MATERIAL AND METHODS: Periodontal structures, TMJ and skull shape of hTNFtg mice and wild-type (WT) littermates were assessed by microcomputed tomography, automated segmentation, geometric morphometrics and histologic ground sections. RESULTS: We show that hTNFtg mice have an eroded lamina dura and reduced periodontal ligament space compared to (WT) littermates. Transgenic mice further exhibit severe destruction of the TMJ. Geometric morphometrics revealed that hTNFtg mice have a more laterally positioned TMJ with a concomitantly enlarged zygomatic process. Mandibular and maxillary teeth occluded properly. CONCLUSIONS: Our findings suggest that chronic inflammation in hTNFtg mice causes destructive changes of the periodontium and the TMJ.

Development and capture of soft tissue contours at time of implant placement.

A technique is described which will generate a customized healing abutment for a dental implant to allow the development of ideal soft tissue contours. With implant position and soft tissue contours defined at surgery, customized impression techniques can be used to capture those details and help generate the definitive implant-supported restoration. This workflow reduces the number of patient visits.

Evaluation of Periodontal Changes Adjacent to Extraction Sites during Upper Canine Retraction.

INTRODUCTION: There is an intimate relationship between orthodontic therapy and the periodontal changes that occur during tooth movement. MATERIALS AND METHODS: This prospective clinical trial aims at investigating the movement of both the free and attached gingiva, as well as the movement of the alveolar bone in the extraction site of the upper 1st premolars during the retraction of the upper canines. In this study, 17 patients (10 female, 7 male) requiring 1st premolar extraction before orthodontic tooth movement were selected and treated at the Department of Orthodontics in the Faculty of Dentistry in University of Hama, Hama, Syria. The upper 1st premolars were extracted, and the implant AutoTacs were applied on the alveolar bone afterward. Then, measurements between the center of the implant AutoTacs and the L-shape wire were taken, utilizing digital Vernier caliper. After 3 weeks of extraction, tattooing marked points were placed on the free and the attached gingival, and the measurements were taken using the same digital Vernier caliper. Closed coil springs made of nickel-titanium were used to retract the upper canines, and a force of 150 gm was applied. RESULTS: The results of this study showed significant differences between the movement of both the free and attached gingiva and the movement of the corresponding upper canines (p < 0.001). The movement of the free gingiva had formed about 77% of the amount of the movement of the upper canine retraction. No significant differences were detected between the place of implant AutoTac X1 and the L-shaped wire (W) during the retraction of the upper canine. On the contrary, significant differences were noticed between the place of implant AutoTac X2 and the L-shaped wire (W) during the retraction of the upper canine (p < 0.001). CONCLUSION: There is significant movement of hard and soft tissues during and after premolar extraction and orthodontic therapy. CLINICAL SIGNIFICANCE: The movement of supporting tissues of the teeth along with the alveolar bone during canine retraction is an important biological characteristic of the orthodontic tooth movement. Clinicians need to understand the role and importance of the supporting tissues during orthodontic treatment, which needs to be incorporated into their routine clinical evaluations.

Effect of the Keratinized Mucosa Width on the Health Status of Periimplant and Contralateral Periodontal Tissues: A Cross-sectional Study.

INTRODUCTION: The purpose of this study was to examine whether the width of keratinized mucosa (WKM) is associated with the health status of tissue surrounding dental implants and the contralateral teeth. MATERIALS AND METHODS: Sixty patients who received implant-fixed unilateral prostheses in the premolar or molar region were recruited for the study. The following parameters were measured for each implant and contralateral tooth: WKM, gingival index (GI), probing pocket depth (PPD), bleeding on probing (BOP), pus discharge, plaque accumulation (PA), gingival recession (GR), and difficulty of brushing. The effect of the WKM on the health status of the surrounding tissue was evaluated by comparing the different WKM groups (WKM < 2 mm vs WKM ≥ 2 mm). RESULTS: Implants with a WKM <2 mm demonstrated significantly greater PPD, PA, and a higher rate of BOP compared with implants with a WKM ≥2 mm. There was significantly greater GR in contralateral teeth with a WKM <2 mm compared with a WKM ≥2 mm. In addition, implant sites had a higher rate of BOP compared with the contralateral teeth. CONCLUSIONS: Inadequate keratinized mucosa decreased cleansibility of implant sites and increased mucosal inflammation. There is a possibility that PA in implant sites caused more pronounced inflammatory response compared to contralateral tooth.

A root canal filling per se does not have a significant negative effect on the marginal periodontium.

AIM: To evaluate the periodontal status of single-rooted endodontically treated teeth (ET), correcting for patient- and tooth-related factors. METHODS: Clinical parameters (BoP,PD,CAL) of 240 ET and 240 contralateral vital teeth (VT), before and after non-surgical periodontal treatment, were extracted retrospectively from the journals of 175 patients. Possible patient-related (age, gender, smoking status) and tooth-related (interproximal restoration, root canal filling's extent, post, tooth type) confounders were tested. RESULTS: At baseline, frequency of BoP at an interproximal site at ET versus VT was 70.4% versus 65.0%, respectively. The frequency of teeth with interproximal PD ≥ 5 mm and CAL ≥ 5 mm was 47.9% versus 42.9% and 54.6% versus 49.6% at ET and VT, respectively. Interproximal PD and CAL at ET versus VT were 3.86 versus 3.61 mm and 4.11 versus 3.95 mm. After correcting for tooth-related factors, no significant differences were observed between ET and VT. An improper restoration had a significant (p < 0.001) negative effect on BoP [OR 3.49 (95%CI: 1.95-6.27)], PD [36.81% (95%CI: 18.52-57.92)] and CAL [27.01% (95%CI: 12.67-43.18)]. No significant differences between ET and VT were observed regarding clinical outcome of non-surgical periodontal therapy. CONCLUSIONS: Presence of a root canal filling per se does not have a significant negative influence on the marginal periodontium, when correcting for the quality of the interproximal restoration.

Establishing and managing a periodontal biobank for research: the sharing of experience.

Periodontal bio-repositories, which allow banking of clinically validated human data and biological samples, provide an opportunity to derive biomarkers for periodontal diagnosis, prognosis and therapeutic activities which are expected to improve patient management. This article presents the establishing of the Malaysian Periodontal Database and Biobank System (MPDBS) which was initiated in 2011 with the aim to facilitate periodontal research. Partnerships were established with collaborating centres. Policies on specimen access, authorship and acknowledgement policies were agreed upon by all participating centres before the initiation of the periodontal biobank. Ethical approval for the collection of samples and data were obtained from institutional ethics review boards. A broad-based approach for informed consent was used, which covered areas related to quality of life impacts, genetics and molecular aspects of periodontal disease. Sample collection and processing was performed using a standardized protocol. Biobanking resources such as equipment and freezers were shared with the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). In the development of the MPDBS, challenges that were previously faced by the MOCDTBS were considered. Future challenges in terms of ethical and legal issues will be faced when international collaborations necessitate the transportation of specimens across borders.

Clinical, microbiological, and immunological aspects of healthy versus peri-implantitis tissue in full arch reconstruction patients: a prospective cross-sectional study.

BACKGROUND: Due to the world-wide increase in treatments involving implant placement, the incidence of peri-implant disease is increasing. Late implant failure is the result of the inability to maintain osseointegration, whose most important cause is peri-implantitis. The aim of this study was to analyze the clinical, microbiological, and immunological aspects in the peri-implant sulcus fluid (PISF) of patients with healthy dental implants and patients with peri-implantitis. METHODS: PISF samples were obtained from 24 peri-implantitis sites and 54 healthy peri-implant sites in this prospective cross-sectional study. The clinical parameters recorded were: modified gingival index (mGI), modified plaque index (mPI) and probing pocket depth (PPD). The periodontopathogenic bacteria Tannerella forsythia, Treponema denticola and Porphyromonas gingivalis were evaluated, together with the total bacterial load (TBL). PISF samples were analyzed for the quantification of Interleukin (IL)-8, IL-1ß, IL-6, IL-10 and Tumor Necrosis Factor (TNF)-α using flow cytometry (FACS). RESULTS: The mGI and PPD scores in the peri-implantitis group were significantly higher than the healthy group (p < 0.001). A total of 61.5% of the patients with peri-implantitis had both arches rehabilitated, compared with 22.7% of patients with healthy peri-implant tissues; there was no implant with peri-implantitis in cases that received mandibular treatment exclusively (p < 0.05). Concentrations of Porphyromonas gingivalis (p < 0.01), association with bacteria Porphyromonas gingivalis and Treponema denticola (p < 0.05), as well as the TBL (p < 0.05) are significantly higher in the peri-implantitis group. IL-1ß (p < 0.01), IL-6 (p < 0.01), IL-10 (p < 0.05) and TNF-α (p < 0.01) are significantly higher at the sites with peri-implantitis compared to healthy peri-implant tissue, while IL-8 did not increase significantly. CONCLUSION: The results of the present study involving a limited patient sample suggest that the peri-implant microbiota and which dental arch was rehabilitated involved could contribute to bone loss in peri-implantitis. A significant relationship is observed between the concentration of cytokines (interleukins 1ß, 6 and 10 and TNF-α) and the inflammatory response in peri-implantitis tissue.

Periodontal considerations in veneer cases.

Porcelain veneers are a minimally invasive technique to enhance patients' smiles. A crucial component in these cases is the supporting periodontal apparatus and its interaction with the restorations. This article addresses basic concepts such as biologic width, altered eruption patterns, appropriate gingival contouring and smile design to give practitioners the tools to diagnose, evaluate and treat cases successfully and predictably.

Critical buccal bone dimensions along implants.

The buccal bone plate is a component of the alveolar process tightly related to the tooth it supports. A plethora of physiological and pathological events can induce its remodeling. Understanding this remodeling process and its extent is of major importance for the practitioner as it can affect the functional and esthetic outcome of implant surgery at the involved sites. Bone remodeling and resorption of the buccal bone plate are inevitable after tooth loss or extraction. To limit resorption, several ridge-preservation techniques of varying efficacy have been described. Bone resorption is equally found to occur upon implant placement and is thought to be a result of the surgical trauma inflicted as well as an adaptation process of the tissues to the new foreign body. Because of the implications of bone resorption on the soft-tissue levels and the general esthetic outcome, it is of primary importance for the practitioner to be able to evaluate the hard tissues and the inherent resorption risks in an effort to optimize the treatment strategies. Based on limited short-term data, the present general opinion advises the need for a 2-mm-thick buccal bone plate in order to avoid vertical bone resorption.

Critical soft-tissue dimensions with dental implants and treatment concepts.

Dental implants have proven to be a successful treatment option in fully and partially edentulous patients, rendering long-term functional and esthetic outcomes. Various factors are crucial for predictable long-term peri-implant tissue stability, including the biologic width; the papilla height and the mucosal soft-tissue level; the amounts of soft-tissue volume and keratinized tissue; and the biotype of the mucosa. The biotype of the mucosa is congenitally set, whereas many other parameters can, to some extent, be influenced by the treatment itself. Clinically, the choice of the dental implant and the position in a vertical and horizontal direction can substantially influence the establishment of the biologic width and subsequently the location of the buccal mucosa and the papilla height. Current treatment concepts predominantly focus on providing optimized peri-implant soft-tissue conditions before the start of the prosthetic phase and insertion of the final reconstruction. These include refined surgical techniques and the use of materials from autogenous and xenogenic origins to augment soft-tissue volume and keratinized tissue around dental implants, thereby mimicking the appearance of natural teeth.

Characteristics of periodontal biotype, its dimensions, associations and prevalence: a systematic review.

AIM: The objectives of this review were as follows: What are characteristics used to define various forms of periodontal biotypes? What are their anatomic dimensions in relation to the definition? In addition, what is the association between these various characteristics in relation to the periodontal biotypes? Furthermore, what is the prevalence of various forms of periodontal biotypes in the population? MATERIAL AND METHODS: The PubMed-MEDLINE, the Cochrane-CENTRAL and EMBASE databases were searched through up and till June 2013 to identify any appropriate studies regarding the aim. Appropriate studies were those reporting characteristics of various forms of periodontal biotype and its dimensions. These characteristics were gingival thickness (GT), gingival morphotype (GM), tooth dimensions (TD), keratinized tissue (KT) and bone morphotype (BM). RESULTS AND CONCLUSIONS: The search yielded 2581 unique papers, after selection resulted in 12 publications that met the eligibility criteria. In general, the available definitions are found to be unclear and sometimes inconsistent. However, based on the available literature, the three biotypes thin scalloped, thick flat and thick scalloped seem a comprehensive categorization in defining periodontal biotypes in the population. The dental, gingival and osseous dimensions have a weak to moderate association. Only between gingival thickness, keratinized tissue and bone morphotype uniform positive associations are found.

Improving oral implant osseointegration in a murine model via Wnt signal amplification.

AIM: To determine the key biological events occurring during implant failure and then we use this knowledge to develop new biology-based strategies that improve osseointegration. MATERIALS AND METHODS: Wild-type and Axin2(LacZ/LacZ) adult male mice underwent oral implant placement, with and without primary stability. Peri-implant tissues were evaluated using histology, alkaline phosphatase (ALP) activity, tartrate resistant acid phosphatase (TRAP) activity and TUNEL staining. In addition, mineralization sites, collagenous matrix organization and the expression of bone markers in the peri-implant tissues were assessed. RESULTS: Maxillary implants lacking primary stability show histological evidence of persistent fibrous encapsulation and mobility, which recapitulates the clinical problems of implant failure. Despite histological and molecular evidence of fibrous encapsulation, osteoblasts in the gap interface exhibit robust ALP activity. This mineralization activity is counteracted by osteoclast activity that resorbs any new bony matrix and consequently, the fibrous encapsulation remains. Using a genetic mouse model, we show that implants lacking primary stability undergo osseointegration, provided that Wnt signalling is amplified. CONCLUSIONS: In a mouse model of oral implant failure caused by a lack of primary stability, we find evidence of active mineralization. This mineralization, however, is outpaced by robust bone resorption, which culminates in persistent fibrous encapsulation of the implant. Fibrous encapsulation can be prevented and osseointegration assured if Wnt signalling is elevated at the time of implant placement.

Effects of a new implant abutment design on peri-implant soft tissues.

The purpose of this study was to assess the effects of a modified implant abutment design on peri-implant soft and hard tissues in dogs. Three months after extraction of mandibular premolar teeth, 3 dental implants were placed in each side of the jaw using a 1-stage approach. Implants on one side of the mandible received standard abutments (control), and implants on the contralateral side received modified, patented, grooved abutments (test). Two months after implant placement, animals were euthanized and specimens were prepared for histologic and histomorphometric assessment. The linear distance (in micrometers) was measured from the implant shoulder (IS) to the following landmarks: gingival margin (GM; distance IS-GM), most apical position of the junctional epithelium (JE; distance IS-JE), and bone crest (BC; distance IS-BC). Percent of bone-to-implant contact was also measured. Histologic assessment revealed that all implants were osseointegrated and that interimplant gingival fibers between test abutments appeared to be more numerous and organized than control abutments. The IS-GM and IS-JE distances in test implants were greater than the corresponding distances in control implants (P = .024 and P = .015, respectively), whereas crestal bone loss (IS-BC) was greater for control implants than test implants (P = .037). There were no differences between control and test implants in bone-to-implant contact (P = .69), which averaged close to 50%. These results suggest that the modified groove design incorporated in standard abutments confers both soft and hard tissue benefits.

Hard and soft tissue considerations at mini-implant insertion sites.

Various factors influence where orthodontic mini-implants will be placed. This article highlights the pertinent variables that should find consideration when planning the placement of orthodontic mini-implants.

A systematic approach to definitive planning and designing single and multiple unit implant abutments.

With an increase in the availability of implant restorative components, the selection of an appropriate implant abutment for a given clinical situation has become more challenging. This article describes a systematic protocol to help the practitioner more thoughtfully select abutments for single and multiple unit fixed implant prostheses. The article examines the evaluation, planning, design, and fabrication processes for the definitive restoration. It includes an assessment of a variety of factors, namely restorative space, soft and hard tissues, the location of the implant platform, the type of platform connection, platform switching indications, tissue collar heights, emergence profile, implant angulation, and finally the design and esthetic options for the final implant abutment.