Root Submergence Research Articles

Root Submergence of Permanent Incisors After Complicated Crown-Root Fracture during Adolescence: Case Reports

Root Submergence of Permanent Incisors After Complicated Crown-Root Fracture during Adolescence: Case Reports

Partial Extraction Therapies (PET) Part 2: Procedures and Technical Aspects.

Part 1 of this series introduced the partial extraction therapies as a group of techniques for ridge preservation at immediate implant placement and beneath pontic sites. The concept proposes a paradigm shift away from extract and augment toward partly retaining the tooth root to preserve the ridge and prevent buccopalatal collapse. The revolutionary socket-shield technique was introduced in 2010; however, there has been no follow-up literature to guide the clinician in terms of procedural steps. While root submergence is well established, the socket-shield and pontic shield are still in their clinical infancy and require long-term clinical data before they can be proposed as routine in everyday implant dentistry. Yet without sound knowledge on how to carry out the partial extraction therapies, a global dental community cannot participate in their application or contribute to the growing knowledge base. In this, the second part of the series, the procedures for root submergence, socket-shield, and pontic shield are addressed, step by step, supplemented with applicable guidelines as the first such publication guiding the clinician to apply these root- and ridge-preservation techniques. Technical aspects and complication management are also addressed.

Partial Extraction Therapies (PET) Part 1: Maintaining Alveolar Ridge Contour at Pontic and Immediate Implant Sites.

Buccopalatal collapse of the postextraction ridge is a significant challenge in restorative and implant dentistry. A variety of ridge preservation techniques using tissue and augmentative materials have been proposed in the literature. A slightly different approach is to use the tooth itself. Root submergence has been reported in the literature for more than 4 decades, and it has been demonstrated that the submerged tooth root retains the periodontal tissues and preserves the bone in pontic sites or below dentures to retain the ridge. The socket-shield technique entails preparing a tooth root section simultaneous to immediate implant placement and has demonstrated histologic and clinical results that are highly promising to esthetic implant treatment. The pontic shield technique preserves the alveolar ridge at sites intended for pontic development where the root submergence technique is not possible. The aforementioned techniques collectively may be termed partial extraction therapies (PET), a term newly introduced into the literature and clinical environment. This article is a review of these ridge preservation therapies, providing a classification and a guide to their application.

The Pontic-Shield: Partial Extraction Therapy for Ridge Preservation and Pontic Site Development.

Augmentive ridge preservation techniques aim to manage the postextraction ridge. The partial extraction of teeth may better preserve the ridge form by maintaining the bundle bone-periodontal ligament apparatus. Root submergence has been demonstrated to retain the periodontal tissues and preserve the ridge beneath dentures or fixed prostheses. The socket-shield technique entails preparing a tooth root section simultaneous to immediate implant placement and has demonstrated histologic and clinical results contributory to esthetic implant treatment. A retrospective 10-patient case series treating 14 partial extraction sites demonstrates how a modification of the socket-shield technique can successfully develop pontic sites and preserve the ridge.

Management of a Failed Implant Site with Guided Bone Regeneration, Reimplantation, and Root Submergence Technique

Management of a Failed Implant Site with Guided Bone Regeneration, Reimplantation, and Root Submergence Technique

A root submergence technique for pontic site development in fixed dental prostheses in the maxillary anterior esthetic zone

This case report discusses the effect of a root submergence technique on preserving the periodontal tissue at the pontic site of fixed dental prostheses in the maxillary anterior aesthetic zone. Teeth with less than ideal structural support for fixed retainer abutments were decoronated at the crestal bone level. After soft tissue closure, the final fixed dental prostheses were placed with the pontics over the submerged root area. Radiographic and clinical observations at the pontic sites were documented. The submerged roots at the pontic sites preserved the surrounding periodontium without any periapical pathology. The gingival contour at the pontic site was maintained in harmony with those of the adjacent teeth, as well as the overall form of the arch. The results of this clinical report indicate that a root submergence technique can be successfully applied in pontic site development with fixed dental prostheses, especially in the maxillary anterior esthetic zone.

The role of nodules in the tolerance of common bean to iron deficiency

Iron is vital for the establishment and function of symbiotic root nodules of legumes. Although abundant in the environment, Fe is often a limiting nutrient for plant growth due to its low solubility and availability in some soils. We have studied the mechanism of iron uptake in the root nodules of common bean to evaluate the role of nodules in physiological responses to iron deficiency. Based on experiments using full or partial submergence of nodulated roots in the nutrient solution, our results show that the nodules were affected only slightly under iron deficiency, especially when the nodules were submerged in nutrient solution in the tolerant cultivar. In addition, fully submerged root nodules showed enhanced acidification of the nutrient solution and showed higher ferric chelate reductase activity than that of partially submerged roots in plants cultivated under Fe deficiency. The main results obtained in this work suggest that in addition to preferential Fe allocation from the root system to the nodules, this symbiotic organ probably develops some mechanisms to respond to iron deficiency. These mechanisms were implied especially in nodule Fe absorption efficiency and in the ability of this organ to take up Fe directly from the medium.

Pontic site development with a root submergence technique for a screw-retained prosthesis in the anterior maxilla

Techniques for pontic site development usually involve various hard and soft tissue augmentation procedures. This article describes an alternative approach to developing a pontic site by using a root submergence technique for a screw-retained fixed dental prosthesis in the anterior maxilla.

Formin homology 1 (OsFH1) regulates submergence-dependent root hair development in rice plants

By using a forward genetic approach, a formin homology 1 gene (OsFH1) was identified as a critical regulator of rice root hair development. The phenotypic effect of OsFH1 on root hair development was verified by using three independent mutants, one point mutation and two T-DNA insertions. The study showed that OsFH1 is required for the elongation of root-hairs. However, Osfh1 exhibited growth defect of root hairs only when roots were grown submerged in solution. To understand how OsFH1 impinges on plant responses to root submergence, the growth responses of Osfh1 root hairs to anoxia, carbohydrate supplementation and exogenous hormones (auxin and ethylene) and nutrients (Fe and Pi) were examined. However, none of these treatments rescued the growth defects of Osfhl1 root hairs. This study demonstrates that OsFH1 could be involved in preventing submergence-induced inhibition of root hair growth.

Prosthodontic treatment using vital and non vital submerged roots-two case reports.

Residual ridge resorption has been considered as an inevitable consequence after extraction of the teeth. There is a gradual loss of the alveolar bone due to the pattern of bone remodeling. In spite of the availability of newer treatment modalities like endodontic restoration and periodontic procedures for preservation of the remaining teeth they are not feasible for the patients in severe stages where restoration might not be possible. The only reliable method of preserving the remaining bone is by maintaining the functional health of the teeth. Over the years, many studies showed that roots which are fractured and left behind during extractions are retained into the alveolar bone with no evidence of pathosis. Over denture as a treatment option was developed in an effort to preserve the remaining alveolar bone by retaining the natural teeth or roots. In over denture treatment, the teeth selected as abutments are prone to caries and periodontal disease over a period of time, hence evolved the vital or non vital root submergence concept. After a thorough radiographic and clinical examination, few teeth without pathosis are retained that eventually are surgically submerged in the alveolar ridge. After healing, the over denture with reaining vital or non vital teeth preserve the integrity of the bone, making the treatment an effective and successfull preventive prosthodontic treatment.

Modified root submergence technique for multiple implant-supported maxillary anterior restorations in a patient with thin gingival biotype: A clinical report

Preserving or recreating the soft tissue contours when restoring multiple tooth defects with implants is challenging. When the interimplant distance is less than 3 mm, a loss of the papilla may be observed.1–2 This is due partly to the remodeling of bone around the implant and restitution of the biologic width when the implant is placed in function.3 The loss of papilla has also been linked to a decrease in vascular supply to the periimplant soft tissue.4 The reduction in papilla height will negatively affect the reproduction of a scalloped gingival architecture.

P.057 Bisphosphonate induced osteonecrosis: surgical case reports

As socket grafting with commercially available biomaterials has become popular, reports of the root submergence technique for ridge preservation have decreased. A systematic review of this partial extraction therapy is lacking.The purpose of this systematic review was to review the root submergence technique as well as critically appraise the available data.A review was carried out that observed the Participant, Intervention, Comparison, Outcomes (PICO) strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The focused question was “What are the outcomes of the different methods to submerge tooth roots for ridge preservation?” Medical subject headings (MeSH) terms that related to the root submergence technique were searched in PubMed/MEDLINE, Scopus, and the Cochrane Library databases.A total of 7709 abstracts and study titles were individually screened from the initial search results. After reviewing the full-text articles and applying the selection criteria, the final included search results totaled 47 full-text articles for in-depth review. In 10 animal studies, 258 roots were studied in 34 dogs and 7 monkeys. Histological data confirmed that coronal bridging (bone or cementum growth over the cut root) was a common outcome. Of the vital roots submerged, the majority maintained their vitality. In 37 human studies, 475 roots were submerged and reported on. Subjective ridge preservation was often reported. Among the adverse healing outcomes, exposure of the root through the mucosa was the most common. Nonetheless, in animals, 86.8% of roots remained submerged; in humans, 74.7%.Root submergence is an established technique for ridge preservation. Exposure is a common complication, and correct technique may be key to its prevention. Further research of this partial extraction therapy is encouraged.

Endodontic Surgery: An Online Study Guide

The Editorial Board of the Journal of Endodontics has developed a literature-based study guide of topical areas related to endodontics. This study guide is intended to give the reader a focused review of the essential endodontic literature and does not cite all possible articles related to each topic. Although citing all articles would be comprehensive, it would defeat the idea of a study guide. This section will cover indications and contraindications, surgical anatomy related to endodontics, flap design, root-end resection, the beveled root surface, root-end preparation techniques, root-end filling materials, endodontic surgical aids, endodontic surgical wound healing, incision and drainage, surgical trephination, intentional replantation, endodontic endosseous implants, submergence of roots, transplantation of teeth, and cystic decompression.

A novel nonsymbiotic hemoglobin from oak: cellular and tissue specificity of gene expression

This study presents the isolation and characterization of a novel nonsymbiotic Hb gene from sessile oak (Quercus petraea) seedlings, herein designated QpHb1. The cellular and tissue expression of QpHb1 was analysed by Northern blotting and in situ hybridization. The encoded protein was predicted to consist of 161 amino acid residues, and shares 71 and 51% amino acid sequence identity with the Arabidopsis class 1 and 2 nonsymbiotic Hb, respectively. Northern blot analysis revealed that QpHb1 was strongly expressed in roots. Spatial expression analysis of QpHb1 in the root apical region of sessile oak by in situ hybridization indicated that transcripts were mostly abundant in protoxylem cell initials, some cortical cells and the protoderm. In addition, when comparing the expression profile of QpHb1 in sessile and pedunculate oak (Quercus robur), two species with contrasted hypoxia tolerance, the transcript level of QpHb1 rose early in the most flood-tolerant species, pedunculate oak, during root submergence. The spatial-temporal expression of QpHb1 suggests that this gene could participate in perception and signalling during hypoxia.

Photosynthesis and Dark Respiration in Leaves of Different Ages of Partly Flooded Maize Seedlings

Maize seedlings were flooded for periods from 1 to 15 days, and the leaves of different ages were then taken to examine photosynthesis, dark respiration, transpiration, chlorophyll content, and some morphometric parameters. The responses of leaves to root submergence essentially depended on the leaf layer and the treatment duration. A short-term flooding (1–24 h) induced primary stress responses in the first leaf. Photosynthesis and respiration in this leaf oscillated around the control levels with amplitudes of ±15–25% and ±40–60%, respectively. After a longer flooding, the CO2 exchange in the second leaf was suppressed, while oxygen uptake was stimulated. In the third leaf, which was formed during submergence, the photosynthetic rate increased and the respiratory activity decreased. The transpiration rate did not change in these leaves for 15 days of flooding. The hypoxic treatment, at its early stages, retarded growth and disturbed the source–sink relations. At later stages the plants adapted to hypoxic environment: the seedling growth was restored, which elevated the demand for assimilates and stimulated photosynthesis. It is concluded that plants overcome negative impact of the root hypoxia at the systemic level.

Survival of intentionally retained permanent incisor roots following crown root fractures in children.

Retaining tooth roots, following crown loss, confers a number of benefits including the preservation of alveolar bone. Intentional root retention in adults has been widely investigated but little is known about this treatment approach in children. Therefore, the aim of the present study was to investigate the clinical outcomes associated with permanent anterior root retention in a young population. The study group comprised 53 children who had received treatment in the paediatric dentistry clinic, Charles Clifford Dental Hospital, Sheffield, UK, over the past 10 years, following a complicated crown root fracture of a permanent maxillary incisor at or below the gingival margin. Data relating to patient age at crown root fracture, gender, previous trauma history, tooth vitality, treatments performed and clinical outcomes were obtained retrospectively using patient records. The mean age of the subjects at initial crown root fracture was 12.1 years (range 8.3-15.8 years) and there were more than twice as many males (n = 37, 70%) as females (n = 16, 30%). In just over half of the cases seen (n = 29, 54%), the tooth involved was already nonvital at the time of crown root fracture. For the majority of these nonvital teeth (n = 27, 93%), primary treatment had comprised placement/replacement of a calcium hydroxide root dressing. The remaining two teeth did not require root treatment as a satisfactory gutta percha root filling was already present. A variety of treatments was undertaken for the 24 vital roots: in 15 (63%) cases the pulp was extirpated and calcium hydroxide placed; three (12%) cases were subject to a pulpotomy; five (21%) cases were left untreated with the hope that vitality would be maintained following gingival healing and in one case the radicular pulp was extirpated and immediately obturated with gutta percha. The mean time that the roots were kept under review was 2.6 years (+/- 1.57, range 0.6-6.8). During this period, only five roots (9%) had to be removed due to persistent periapical infection. There were no complications associated with the five cases where vital root submergence had been permitted but all three cases which had initially undergone a pulpotomy subsequently presented with pulpal necrosis necessitating pulpal extirpation and calcium hydroxide therapy. These findings indicate that efforts to retain permanent anterior roots in a young population are justified in view of the high clinical success rate of over 90% over a 2-year period.

Endodontic therapy and root submersion of an impacted maxillary canine: A case report and review of the root submergence concept

A case report of root submersion of a maxillary canine after endodontic therapy is presented. A review of the rationale and validity of the root submersion concept is also presented.

Assessment of errors in nutrient analyses of roots

Errors in nutrient analyses of roots may arise from soil adhering to roots, the method of root separation from soil and storage of root samples. Experiments were conducted on fine roots of Eucalyptus nitens from a clay soil to establish a method for estimating true concentrations of nitrogen (N), phosphorus (P) and potassium (K) in root samples (i.e. unbiased by the soil adhering to roots), and to test the adequacy of measurements of ash residues of root samples for estimating the quantity of soil adhering to roots. Results indicated that nutrient concentrations on the basis of ash-free weight of root samples approached true nutrient concentrations of roots when the quality of soil adhering to roots was small, and the nutrient concentration of soil was much lower than the roots. Estimates of true nutrient concentrations of roots calculated from the information on the weight of soil adhering to roots and the nutrient concentration of the soil were satisfactory in the prediction of nutrient content of roots for a range of soil-contamination. The factor which accounted for contamination, and helped estimation of true concentrations from measured concentrations, depended on the magnitude of soil contamination and the relative concentrations of nutrients in roots and soil. Wet separation (washing) of roots from soil compared with dry separation resulted in 24% loss of K. With various methods of storage of washed root samples, the level of soil contamination was 5-20% of the root sample. Submergence of roots in water for 15 days after washing reduced the concentration of N, P and K in roots to 84, 50 and 54% of those roots which were dried immediately following washing. The rate of nutrient loss from roots was greater for K than for N and P when washed samples were stored submerged. On the basis of this study, it is recommended that roots, after separation from soil, should be dried as soon as possible with a minimum exposure of roots to wet conditions. Estimates of soil adhering to roots, and nutrient concentration of the adhering soil, are required to infer correct concentrations of nutrients in root samples.

Histopathological change of intentional vital submergence of tooth roots covered by mucoperiosteal flap

Histopathological change of intentional vital submergence of tooth roots covered by mucoperiosteal flap

An experimental study of root submergence for alveolar bone preservation with special reference to vital and endodontically treated roots.

An experimental study of root submergence for alveolar bone preservation with special reference to vital and endodontically treated roots.