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.

Buccal bone thickness of maxillary anterior teeth: A systematic review and meta-analysis.

AIM: To systematically review buccal bone thickness (BBT) in the anterior maxilla in different teeth, age groups and genders. MATERIALS AND METHODS: PubMed, EMBASE and Cochrane databases were searched up to April 2020. Clinical and radiographic studies reporting on BBT of maxillary anterior teeth, with at least 10 patients, were included. A meta-analysis was performed using random effect models to report differences of BBT. RESULTS: 50 studies were included. Using bone crest (BC) as a reference point, no significant differences were found in BBT between different tooth types, except for 0.16 mm (95%-CI: 0.02-0.30) increased mid-root thickness of premolars compared to canines. Using the CEJ as a reference point, canines presented with a significantly increased thickness of 0.32 mm (95%-CI: 0.11-0.54) coronally compared to laterals. When BC was used as reference, males demonstrated a significantly increased thickness of 0.21 mm (95%-CI: 0.15-0.27) apically, while middle-aged adults showed a 0.06 mm (95%-CI: -0.12, -0.01) statistically significant increase in the coronal level compared to older adults. CONCLUSIONS: Few maxillary anterior teeth have BBT greater than 1 mm. Buccal bone tends to get thicker from a coronal to apical position along the root surface and from an anterior to posterior position in the arch.

Oral mucosal changes associated with primary diseases in other body systems.

Systemic diseases may manifest in the oral cavity. This chapter reviews the oral mucosal pathology in blood diseases, gastrohepatic diseases, kidney diseases, immunologic and connective tissue diseases, endocrine diseases, pulmonary diseases, nutritional deficiencies, dermatologic diseases, as well as cancer-associated oral mucosal conditions. The oral mucosa is one of the most commonly affected tissues and may present with unique clinical appearances. Oral mucosal involvement may be the first presentation of the systemic disease or reflect activity or progression of the primary condition. Therefore, it is of importance to be familiar with oral mucosal manifestations of these systemic diseases.

Dental prostheses and tooth-related factors.

OBJECTIVES: This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis. FINDINGS: Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis. CONCLUSIONS: Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

Occlusal trauma and excessive occlusal forces: Narrative review, case definitions, and diagnostic considerations.

OBJECTIVES: This narrative review determines the effects of occlusal trauma and excessive occlusal forces on the periodontium, including the initiation and progression of periodontitis, abfraction, and gingival recession. Case definitions, diagnostic considerations, and the effects of occlusal therapy are also reviewed and discussed. IMPORTANCE: The role of occlusal trauma in the initiation and progression of periodontitis remains a controversial subject in periodontology. Because occlusal trauma can only be confirmed histologically, its clinical diagnosis depends on clinical and radiographic surrogate indicators which make clinical trials difficult. FINDINGS: Investigations have generally agreed that occlusal trauma and excessive occlusal forces do not initiate periodontitis or loss of connective tissue attachment. When plaque-induced periodontitis and occlusal trauma are present at the same time, there is weak evidence that the occlusal trauma may increase the rate of connective tissue loss. Occlusal therapy is indicated as part of periodontal therapy to reduce mobility and increase patient comfort and masticatory function. Existing data do not support the existence of abfraction as a cause for gingival recession. CONCLUSIONS: Occlusal trauma does not initiate periodontitis, and there is weak evidence that it alters the progression of the disease. There is no credible evidence to support the existence of abfraction or implicate it as a cause of gingival recession. Reduction of tooth mobility may enhance the effect of periodontal therapy.

A new classification scheme for periodontal and peri-implant diseases and conditions - Introduction and key changes from the 1999 classification.

A classification scheme for periodontal and peri-implant diseases and conditions is necessary for clinicians to properly diagnose and treat patients as well as for scientists to investigate etiology, pathogenesis, natural history, and treatment of the diseases and conditions. This paper summarizes the proceedings of the World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. The workshop was co-sponsored by the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP) and included expert participants from all over the world. Planning for the conference, which was held in Chicago on November 9 to 11, 2017, began in early 2015. An organizing committee from the AAP and EFP commissioned 19 review papers and four consensus reports covering relevant areas in periodontology and implant dentistry. The authors were charged with updating the 1999 classification of periodontal diseases and conditions and developing a similar scheme for peri-implant diseases and conditions. Reviewers and workgroups were also asked to establish pertinent case definitions and to provide diagnostic criteria to aid clinicians in the use of the new classification. All findings and recommendations of the workshop were agreed to by consensus. This introductory paper presents an overview for the new classification of periodontal and peri-implant diseases and conditions, along with a condensed scheme for each of four workgroup sections, but readers are directed to the pertinent consensus reports and review papers for a thorough discussion of the rationale, criteria, and interpretation of the proposed classification. Changes to the 1999 classification are highlighted and discussed. Although the intent of the workshop was to base classification on the strongest available scientific evidence, lower level evidence and expert opinion were inevitably used whenever sufficient research data were unavailable. The scope of this workshop was to align and update the classification scheme to the current understanding of periodontal and peri-implant diseases and conditions. This introductory overview presents the schematic tables for the new classification of periodontal and peri-implant diseases and conditions and briefly highlights changes made to the 1999 classification. It cannot present the wealth of information included in the reviews, case definition papers, and consensus reports that has guided the development of the new classification, and reference to the consensus and case definition papers is necessary to provide a thorough understanding of its use for either case management or scientific investigation. Therefore, it is strongly recommended that the reader use this overview as an introduction to these subjects. Accessing this publication online will allow the reader to use the links in this overview and the tables to view the source papers (Table ).

Periodontal manifestations of systemic diseases and developmental and acquired conditions: Consensus report of workgroup 3 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

BACKGROUND: A variety of systemic diseases and conditions can affect the course of periodontitis or have a negative impact on the periodontal attachment apparatus. Gingival recessions are highly prevalent and often associated with hypersensitivity, the development of caries and non-carious cervical lesions on the exposed root surface and impaired esthetics. Occlusal forces can result in injury of teeth and periodontal attachment apparatus. Several developmental or acquired conditions associated with teeth or prostheses may predispose to diseases of the periodontium. The aim of this working group was to review and update the 1999 classification with regard to these diseases and conditions, and to develop case definitions and diagnostic considerations. METHODS: Discussions were informed by four reviews on 1) periodontal manifestions of systemic diseases and conditions; 2) mucogingival conditions around natural teeth; 3) traumatic occlusal forces and occlusal trauma; and 4) dental prostheses and tooth related factors. This consensus report is based on the results of these reviews and on expert opinion of the participants. RESULTS: Key findings included the following: 1) there are mainly rare systemic conditions (such as Papillon-Lefevre Syndrome, leucocyte adhesion deficiency, and others) with a major effect on the course of periodontitis and more common conditions (such as diabetes mellitus) with variable effects, as well as conditions affecting the periodontal apparatus independently of dental plaque biofilm-induced inflammation (such as neoplastic diseases); 2) diabetes-associated periodontitis should not be regarded as a distinct diagnosis, but diabetes should be recognized as an important modifying factor and included in a clinical diagnosis of periodontitis as a descriptor; 3) likewise, tobacco smoking - now considered a dependence to nicotine and a chronic relapsing medical disorder with major adverse effects on the periodontal supporting tissues - is an important modifier to be included in a clinical diagnosis of periodontitis as a descriptor; 4) the importance of the gingival phenotype, encompassing gingival thickness and width in the context of mucogingival conditions, is recognized and a novel classification for gingival recessions is introduced; 5) there is no evidence that traumatic occlusal forces lead to periodontal attachment loss, non-carious cervical lesions, or gingival recessions; 6) traumatic occlusal forces lead to adaptive mobility in teeth with normal support, whereas they lead to progressive mobility in teeth with reduced support, usually requiring splinting; 7) the term biologic width is replaced by supracrestal tissue attachment consisting of junctional epithelium and supracrestal connective tissue; 8) infringement of restorative margins within the supracrestal connective tissue attachment is associated with inflammation and/or loss of periodontal supporting tissue. However, it is not evident whether the negative effects on the periodontium are caused by dental plaque biofilm, trauma, toxicity of dental materials or a combination of these factors; 9) tooth anatomical factors are related to dental plaque biofilm-induced gingival inflammation and loss of periodontal supporting tissues. CONCLUSION: An updated classification of the periodontal manifestations and conditions affecting the course of periodontitis and the periodontal attachment apparatus, as well as of developmental and acquired conditions, is introduced. Case definitions and diagnostic considerations are also presented.

Thermodynamic effects of laser irradiation of implants placed in bone: an in vitro study.

Lasers have been proposed for various applications involving dental implants, including uncovering implants and treating peri-implantitis. However, the effect of laser irradiation on the implant surface temperature is only partially known. The aim of this pilot study was to determine the effect of irradiation with diode, carbon dioxide, and Er:YAG lasers on the surface temperature of dental implants placed in bone, in vitro. For this study, one dental implant was placed in a bovine rib. A trephine bur was used to create a circumferential defect to simulate peri-implantitis, and thermocouples were placed at the coronal and apical aspect of the implant. The implant was irradiated for 60 s using four different lasers independently and change in temperature as well as time to reach a 10 °C increase in temperature were recorded. There was wide variability in results among the lasers and settings. Time for a 10 °C increase ranged from 0.9 to over 60 s for the coronal thermocouple and from 18 to over 60 s for the apical thermocouple. Maximum temperature ranged from 5.9 to 70.9 °C coronally and from 1.4 to 23.4 °C apically. During laser irradiation of dental implants, a surface temperature increase beyond the "critical threshold" of 10 °C can be reached after only 18 s.

Morphology of bone particles after harvesting with 4 different devices.

INTRODUCTION: Autogenous bone is routinely used for regeneration of osseous defects around teeth and implants, and different instruments are available for bone harvesting. OBJECTIVES: The purpose of this study was to describe the morphology of bone particles after harvesting with 4 different instruments. MATERIALS AND METHODS: Bone particles were harvested from fresh cow ribs with 2 different types of back action chisels, a safescraper and a sonic device. The samples were examined morphologically using light microscopy and scanning electron microscopy. RESULTS: The bone particles after the back action chisel I had an appearance similar to "pencil shavings." With the back action chisel II, they were like thin paper with an "accordion bellows" appearance. After removal with the safescraper, they had an irregular shape (with an irregular surface) resembling "crushed stone." Finally, the appearance of the bone particles obtained with the sonic device was homogenous, condensed and continuous, and had a "seaweed" appearance. CONCLUSIONS: Harvesting of bone particles with 4 different devices produce distinctly difference sizes and shapes, which may influence the results of grafting procedures.

Dental implant prognostication: A commentary.

In this commentary, a practical system for estimating the prognosis for dental implants is presented. Evidence for factors influencing implant prognosis is reviewed. The system is based on the stability of implant supporting tissues as opposed to implant loss.

Root coverage surgery for dentin hypersensitivity reduction: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate the effectiveness of root coverage surgery in reducing dentin hypersensitivity (DH) through a systematic review and meta-analysis. DATA SOURCES: Unrestricted search of four indexed databases up to September 2022 was performed to identify randomized controlled trials (RCTs) evaluating the effect of root coverage surgery on DH frequency and/or intensity presurgically (baseline) and at least 3 months postsurgically. Two authors independently conducted study screening and data extraction. Subgroup meta-analyses were performed separately for stimulated and unstimulated DH frequency and intensity at different timepoints. The risk of bias and quality of the available evidence were assessed. RESULTS: Nineteen RCTs presenting data from 7 days to 30 months after root coverage surgery with various treatment modalities were included from the 662 identified studies. A total of 486 patients contributed 784 recession defects. Results from the subgroup meta-analyses showed that, overall, root coverage surgery reduced the risk for DH by 67% (RR, 0.33; 95% CI, 0.21 to 0.53) and 53% (RR, 0.47; 95% CI, 0.38 to 0.58) upon unstimulated and stimulated DH assessment, respectively. The DH intensity was also significantly reduced (mean visual analog score difference, 2.37; 95% CI, 2.02 to 2.71) upon stimulated DH assessment. No significant changes in DH intensity were observed upon unstimulated DH assessment. The included studies did not have high risk of bias and the quality of evidence was low to high. CONCLUSION: Existing evidence suggests that root coverage surgery may effectively reduce the DH frequency and intensity.

Application of evidence-based dentistry: from research to clinical periodontal practice.

Dentists need to make daily decisions regarding patient care, and these decisions should essentially be scientifically sound. Evidence-based dentistry is meant to empower clinicians to provide the most contemporary treatment. The benefits of applying the evidence-based method in clinical practice include application of the most updated treatment and stronger reasoning to justify the treatment. A vast amount of information is readily accessible with today's digital technology, and a standardized search protocol can be developed to ensure that a literature search is valid, specific and repeatable. It involves developing a preset question (population, intervention, comparison and outcome; PICO) and search protocol. It is usually used academically to perform commissioned reviews, but it can also be applied to answer simple clinical queries. The scientific evidence thus obtained can then be considered along with patient preferences and values, clinical patient circumstances and the practitioner's experience and judgment in order to make the treatment decision. This paper describes how clinicians can incorporate evidence-based methods into patient care and presents a clinical example to illustrate the process.

Temperature change during non-contact diode laser irradiation of implant surfaces.

A temperature increase of more than 10°C can compromise bone vitality. Laser radiation with different wavelengths has been used for the treatment of peri-implantitis, but little is known about the effect of laser irradiation on temperature rise on the implant surface. In this study, the temperature gradient (∆T) generated by laser irradiation of implant surface using two diode lasers (810 nm and a 980 nm) with 2 W of power has been recorded by two thermocouples (one in the cervical area and one in the apical area) and studied. The 810-nm diode laser showed the following results: after 60 s of irradiation with 2 W of continuous mode the temperature gradient in the cervical area of the implant (∆Tc) was 37.2°C, while in the apical area (∆Ta) was 27.2°C. The 980-nm diode laser showed the following results: after 60 s of irradiation with 2 W continuous mode ∆Tc was 41.1°C, and ∆Ta was 30.6°C. The 810-nm diode laser with 2 W continuous mode generated a temperature increase of 10°C after only 14 s. The 980-nm diode lasers groups produced a much more rapid temperature increase. In only 12 s, the continuous wave of 980 nm reached the 10°C temperature rise. From the present in vitro study it was concluded that the irradiation of implant surfaces with diode lasers may produce a temperature increase above the critical threshold (10°C ) after only 10 s.

The presence of the mandibular incisive canal: a panoramic radiographic examination.

PURPOSE: The mandibular incisive canal (MIC) is the anterior extension of the mandibular canal and its presence is of interest in surgical procedures in the chin region. The aim of this study was to investigate the presence of a MIC in panoramic radiographs (OPGs). METHODS: One thousand forty-five OPGs were randomly chosen from patient population. The data collected included patient characteristics and MIC presence/absence according to the type of the dentition. Measurements (in mm) were performed evaluating the following: (A) minimum and (B) maximum distance from the alveolar ridge; (C) thickness and (D) length of the canal; and (E) distance (in bilateral cases) between the canals. RESULTS: The MIC was found in 2.7% of the patients. CONCLUSIONS: This study demonstrates the frequency of the MIC in OPGs and suggests that this anatomical structure should be considered to prevent injury during surgery.

Comparison of Coronally Advanced Flap and Connective Tissue Graft With or Without Enamel Matrix Derivative for Gingival Recession Treatment: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

The aim of this systematic review and meta-analysis was to assess whether the addition of enamel matrix derivative (EMD) to a coronally advanced flap (CAF) combined with a connective tissue graft (CTG) resulted in a greater amount of root coverage in patients treated for gingival recessions, as compared to CAF+CTG alone. The search for clinical trials on root coverage procedures comparing CAF+CTG+EDM vs CAF+CTG was completed on online databases and gray literature, and it included studies published up to January 2022. The risk of bias was assessed using the Cochrane bias assessment tool, and the quantitative analysis was performed using a random effects model. A total of 1,917 articles were identified, and 12 underwent full-text review. Three studies were excluded, and 9 were selected for full analysis. The meta-analysis showed that there is a statistically significant difference (P = .04) in favor of CAF+CTG+EMD compared to CAF+CTG alone for the amount of root coverage (mean difference: 0.30 mm; 95% CI: 0.01, 0.58 mm). According to the results of this systematic review and meta-analysis, the addition of EMD to CAF+CTG results in a greater amount of root coverage in teeth treated for gingival recessions.

Evaluation of the Accuracy of a New Geometric Approach to Implant Guidance.

PURPOSE: Implant surgical guides are often fabricated using CBCT technology. In this study, an alternative technique is proposed. The aim of this in vitro study was to compare the accuracy of the guide sleeve corrections of a geometric approach to guided surgery to the accuracy of in vitro studies of stereolithographic guides. MATERIALS AND METHODS: Four arch forms were milled from acrylic blocks each with 12 root form sites. Root form inserts were made. Holes were milled in the inserts at arbitrary angles. Guide posts were placed in these sites. Guide sleeves were placed on the posts and connected with light-cured resin to form verification jigs. The goal was to correct the angles of the guide sleeves to a vertical position 90 degrees from the base of the arch forms. The initial angles from the vertical and horizontal positions of the center of each guide sleeve were determined radiographically and geometrically. Horizontal and angle corrections were made using two-piece guide posts. Guide sleeves placed over the corrected guide posts were connected with light-cured resin, forming new verification jigs. The accuracy of the angle correction and the coronal horizontal and apical horizontal deviations of the 3-mm guide sleeves were determined. The experimental sites were divided into two groups to determine if the size of the initial angles of the guide sleeves had any effect on the accuracy of the corrections. RESULTS: The initial angles of the guide sleeves before corrections revealed the mean difference between the two methods of measurements in groups 1 and 2 as 0.36 degrees (P = .14) and 0.69 degrees (P = .07), respectively. A comparison of the angle error measurements from 90 degrees after corrections between the two groups in the mesiodistal and buccolingual planes was not significant. The coronal and apical horizontal deviations after corrections revealed a significant difference between the two groups at the coronal level (P = .005) but not at the apical level (P = .14). In comparison of the methods of the two measurements of the angle error from vertical after corrections, the mean difference was 1.23 degrees (P = .01) and 0.69 degrees (P = .02). CONCLUSION: The in vitro accuracy of the guide sleeve corrections made with the geometric approach for implant guidance was compared to the results of the meta-analyses of in vitro studies of implant placement with stereolithographic guides. The mean errors were smaller and within the recommendations of the EAO Consensus Conference of 2012.

Comparison of maxillary tuberosity and palatal donor sites for soft tissue augmentation at implant placement: A pilot controlled clinical study.

PURPOSE: To compare the outcomes of soft tissue augmentation during one-stage implant placement using grafts harvested from the hard palate or the maxillary tuberosity. MATERIALS AND METHODS: In this pilot controlled clinical study, non-smoking adults with a single missing tooth in the anterior or premolar region and adequate ridge dimensions for implant placement were enrolled. Each received a single implant and connective tissue graft harvested either from the hard palate (n = 10) or the maxillary tuberosity (n = 10). Digital impressions were taken prior to treatment (T0) and then 2 and 12 months postoperatively (T1 and T2, respectively). The primary study outcome was changes in horizontal ridge dimension. Secondary outcomes included marginal bone level changes over time, pain levels in the first 2 postoperative weeks (W1 and W2) and pink aesthetic score and patient-reported outcome measures at T2. Data analysis included repeated measures analysis of variance for intergroup comparisons. RESULTS: The horizontal ridge dimension increased significantly in both groups (P ≤ 0.002) at all apico-coronal levels examined, with no significant intergroup differences. There was also no significant intergroup difference in marginal bone level changes (P = 0.376). The hard palate group experienced higher pain levels in the donor site compared to the tuberosity group at W1 (P = 0.023). The pink aesthetic score and patient-reported outcome measures were similar between groups at T2. CONCLUSIONS: Soft tissue augmentation during one-stage implant placement results in significant increases in the horizontal ridge dimension.

Clinical studies on the management of periodontal diseases utilizing subantimicrobial dose doxycycline (SDD).

Periodontitis, the most common chronic inflammatory condition known to mankind, is a disease that results in the destruction of tooth supporting tissues. Periodontitis is initiated by a bacterial biofilm on the tooth surface below the gingival margin. Until fairly recently it was assumed that the bacteria were the primary cause of tissue destruction, however, a large body of research has revealed that it is the patient's immune response that is actually responsible for the majority of the breakdown of tooth supporting tissues. Contemporary thinking suggests that successful, long term management of chronic periodontitis may combine both local mechanical and antimicrobial strategies to reduce the microbial bio-burden along with modulation of the host, patient's excessive, immuno-inflammatory response to the bacterial exposure known as host modulatory therapy (HMT). Based on extensive literature documenting the enzymatic inhibition and related anti-inflammatory properties of the tetracyclines, a new drug was developed as a host modulatory agent and approved by the United States Food and Drug Administration (FDA) for use as an adjunct to conventional scaling and root planing for the treatment of chronic periodontitis. A subantimicrobial dose of doxycycline (SDD) at 20 mg (Periostat(®)) has been found to be a safe and effective adjunct when taken twice daily for at least 3 months and up to 24 months in randomized placebo controlled clinical trials. Periostat(®) is currently the only FDA approved inhibitor of the matrix metalloproteinases implicated in the plaque-induced pathologic degradation of connective tissue collagen of the periodontal supporting structures. This review paper begins with a brief description of the disease process known as periodontitis followed by an extensive review of the Phase I-IV clinical trial data that established the safety and efficacy of sub-antimicrobial dose doxycycline (SDD) as an adjunct to scaling and root planing for the treatment of periodontitis.

Temperature increase during CO(2) and Er:YAG irradiation on implant surfaces.

PURPOSE: The purpose of this study was to evaluate the temperature gradient (ΔT) generated by laser irradiation of an implant surface using a carbon dioxide (CO(2)) and an Erbium:yttrium aluminium garnet (Er:YAG) laser. MATERIALS AND METHODS: A dental implant was irradiated with a CO(2) and an Er:YAG lasers, with variable power settings. Temperature increase was measured in 2 locations of the implant surface: in the cervical area (ΔT(c)) and in the apical area (ΔT(a)). RESULTS: The CO(2) laser showed the following results: after 60 seconds of irradiation with continuous mode, ΔT(c) was 13.9°C and ΔTa was 12.5°C. The Er:YAG laser showed the following results: after 60 seconds of irradiation with continuous mode, the temperature rise ΔT(c) was 50.6°C and ΔT(a) was 38.6°C. The CO(2) laser with continuous mode generated a temperature increase of 10°C after only 36 seconds. The Er:YAG laser with continuous mode produced a more rapid temperature increase and took only 10 seconds to reach the critical threshold. CONCLUSIONS: The irradiation of implant surfaces with CO(2) and Er:YAG lasers may produce a temperature increase above the critical threshold (10°C) after 10 seconds of continuous irradiation.

Electrospun core-shell nanofibers with encapsulated enamel matrix derivative for guided periodontal tissue regeneration.

The osteogenic effect of a composite electrospun core-shell nanofiber membrane encapsulated with Emdogain® (EMD) was evaluated. The membrane was developed through coaxial electrospinning using polycaprolactone as the shell and polyethylene glycol as the core. The effects of the membrane on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) were examined using Alizarin Red S staining and qRT-PCR. Characterization of the nanofiber membrane demonstrated core-shell morphology with a mean diameter of ~1 µm. Examination of the release of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) from core-shell nanofibers over a 22-day period showed improved release profile of encapsulated proteins as compared to solid nanofibers. When cultured on EMD-containing core-shell nanofibers, PDLSCs showed significantly improved osteogenic differentiation with increased Alizarin Red S staining and enhanced osteogenic gene expression, namely OCN, RUNX2, ALP, and OPN. Core-shell nanofiber membranes may improve outcomes in periodontal regenerative therapy through simultaneous mechanical barrier and controlled drug delivery function.