Decoronation of an ankylosed tooth for preservation of alveolar bone prior to implant placement*

Abstract – A 12‐year‐old patient sustained avulsions of both permanent maxillary central incisors. Subsequently, both teeth developed replacement resorption. The left incisor was extracted alio loco. The right incisor was treated by decoronation (removal of crown and pulp, but preservation of the root substance). Comparison of both sites demonstrated complete preservation of the height and width of the alveolar bone at the decoronation site, whereas the tooth extraction site showed considerable bone loss. In addition, some vertical bone apposition was found on top of the decoronated root. Decoronation is a simple and safe surgical procedure for preservation of alveolar bone prior to implant placement. It must be considered as a treatment option for teeth affected by replacement resorption if tooth transplantation is not feasible.     

Prognostic factors for alveolar regeneration: bone formation at teeth and titanium implants

OBJECTIVES: There is a limited understanding of the effect of defect characteristics on alveolar bone healing. The objectives of this study were to assess the effect of alveolar bone width and space provision on bone regeneration at teeth and titanium implants, and to test the hypothesis that the regenerative potentials at teeth and implants are not significantly different. METHODS: Critical size, 5-6-mm, supra-alveolar, periodontal defects were surgically created in 10 young adult dogs. Similarly, critical size, 5-mm, supra-alveolar, peri-implant defects were created in four dogs. A space-providing expanded polytetrafluoroethylene device was implanted for guided tissue regeneration/guided bone regeneration. The animals were euthanized at 8 weeks postsurgery. Histometric analysis assessed alveolar bone regeneration (height) relative to space provision by the device and the width of the alveolar crest at the base of the defect. Statistical analysis used the linear mixed models. RESULTS: A significant correlation was found between bone width and wound area (r=0.55892, p<0.0001). Generally, bone width and wound area had statistically significant effects on the extent of bone regeneration (p<0.0005 and p<0.0001, respectively). Bone regeneration was linearly correlated with the bone width at periodontal (p<0.001) and implant (p=0.04) sites, and with the wound area at periodontal (p<0.0001) and implant (p=0.03) sites. The relationships of bone regeneration with these two variables were not significantly different between teeth and implants (bone width: p=0.83; wound area: p=0.09). When adjusted for wound area, bone regeneration was significantly greater at periodontal than at implant sites (p=0.047). CONCLUSIONS: The horizontal dimension of the alveolar bone influences space provision. Space provision and horizontal dimension of the alveolar bone appear to be important determinants of bone regeneration at teeth and implants. The extent of alveolar bone formation at implant sites is limited compared with that at periodontal sites.     

Segmental alveolar distraction for the correction of unilateral open-bite caused by multiple ankylosed teeth: A case report

Abstract

Ankylosed teeth fail to erupt to meet their counterparts in the opposite jaw. In cases where ankylosis occurs in multiple teeth, the occlusion shows an open bite. This article describes a case of unilateral open bite caused by multiple ankylosed teeth, where treatment involved segmental alveolar bone distraction. A 25-year-old female patient presented with a left-sided unilateral open bite. On the left-hand side, only the lower incisors were not ankylosed. On the right, the maxillary first molar was ankylosed. All these ankylosed teeth were positioned below the occlusal plane. Her mother and brother also had multiple ankylosed teeth, and a familial cause was considered. Orthodontic tooth movement was considered impossible and segmental osteotomy on the left maxillary alveolar bone and downward bone distraction were performed as an alternative. A distractor consisting of orthodontic bands, wires and screws was devised and worn in the left mandibular dentition. Multi-bracket orthodontic appliances were also used for distraction. The amount of vertical movement was 7 mm at the premolar region. Five months after distraction, the multibracket appliance was removed, and fixed and removable retainers were placed. Eight months after distraction, prosthodontic restorations on the occlusal surfaces of the ankylosed teeth were made to obtain the final occlusion. The unilateral open bite was successfully treated and a good occlusion was obtained. The occlusion has shown good long-term stability for more than 3 years.     

A clinical and histomorphometric study of calcium sulfate compared with freeze-dried bone allograft for alveolar ridge preservation

Background: Many materials have been found to be effective in ridge preservation. The purpose of this study is to determine whether calcium sulfate (CS) is as effective as freeze‐dried bone allograft (FDBA) in preserving postextraction ridge dimensions and to evaluate the amount of new bone formation and graft clearance through histologic analysis. Methods: Thirty‐one extraction sites were selected. Postextraction clinical measurements were made, and sites were divided randomly into the test group (CS) or the control group (FDBA). After graft placement, all individuals received the same postoperative treatment and instructions. Participants were recalled after 3 months, measurements were made, and sites were re‐entered. Bone samples were harvested and analyzed with histologic methodology for new bone formation and remaining residual graft. Results: Thirteen test and 15 control sites were evaluated. There was no significant change in vertical ridge height before or after surgery within the test and control groups (P = 0.57, P = 0.68, respectively). There was a significant decrease in bucco‐lingual ridge width for both groups (P = 0.0003, P = 0.0075, respectively), but the difference between groups was not significant (P = 0.11). Histologic analysis revealed an average of 32% new bone formation with 2.5% graft remaining for the test group and 16.7% new bone formation with 21% graft remaining for the control. Conclusions: Results indicate that CS is as effective as FDBA in preserving postextraction ridge dimensions in non‐molar extraction sites. There is greater clearance of CS with more new bone formation after ≈3 months compared with FDBA in these sites. This paper received the Maynard K. Hine Award for Excellence in Dental Research presented by the Indiana Section of the American Association for Dental Research and supported by Procter & Gamble.     

Dental implant placement through impacted teeth or residual roots as an alternative to invasive extraction surgeries: a systematic literature review

This work systematically reviews dental implant placement through impacted teeth or residual roots, as an alternative to invasive extraction surgeries, evaluated in terms of survival rates, marginal bone loss, surgical, and prosthetic complications. The authors conducted an electronic search of four databases up to September 2020; also a complementary handsearch was carried out. The quality of the included studies was assessed using a protocol for assessment of risk of bias in exposure studies. Ten studies fulfilled the inclusion criteria and were analysed. A total of 44 patients received 62 dental implants and were monitored for a minimum of 12-months follow-up. An overall mean implant survival rate was 90.32%, reporting 97.56 % for dental implants through impacted teeth and 76.19% through residual roots. No surgical or prosthetic complications were reported. Placing dental implants through impacted teeth may offer a valid therapeutic option for implant-supported restorations in patients for whom surgery and orthodontic traction are not possible, and/or patients who refuse to undergo more invasive extraction surgery. Moreover, additional caution is recommended when placing implants through retained root fragments, as this may involve long-term risk. Further research generating long-term data are needed to confirm these findings.     

Avulsed permanent teeth: a review of the literature and treatment guidelines

Abstract Dental trauma represents one of the few situations where dentists are called upon to make unscheduled diagnostic and treatment decisions in an area that is outside their routine experience. Since patients who sustain an avulsion present infrequently, except in child-oriented or emergency-based practices, clinicians often make diagnostic and management decisions based upon their previous rare treatment experiences. Clinicians also rely on published guidelines for this aspect of their practice and expect these standards to be up-to-date and based on current research information. None of the current protocols has been tested by a prospective longitudinal outcome study in humans. Nevertheless, current guidelines have become the standard for clinical practice around the world. An effort must be made to develop treatment protocols that are based upon the biological mechanisms that underlie periodontal wound healing.     

Alveolar ridge preservation with guided bone regeneration and a synthetic bone substitute or a bovine‐derived xenograft: a randomized,controlled clinical trial

Objectives: The aim of this randomized, controlled clinical trial was to compare the potential of a synthetic bone substitute or a bovine‐derived xenograft combined with a collagen membrane to preserve the alveolar ridge dimensions following tooth extraction. Methods: Twenty‐seven patients were randomized into two treatment groups following single tooth extraction in the incisor, canine and premolar area. In the test group, the alveolar socket was grafted with Straumann Bone Ceramic^® (SBC), while in the control group, Bio‐Oss^® deproteinized bovine bone mineral (DBBM) was applied. In both groups, a collagen barrier was used to cover the grafting material. Complete soft tissue coverage of the barriers was not achieved. After 8 months, during re‐entry procedures and before implant placement, the horizontal and vertical dimensions of the residual ridge were re‐evaluated and trephine biopsies were performed for histological analysis in all patients. Results: Twenty‐six patients completed the study. The bucco‐lingual dimension of the alveolar ridge decreased by 1.1±1 mm in the SBC group and by 2.1±1 in the DBBM group (P<0.05). Both materials preserved the mesio‐distal bone height of the ridge. No differences in the width of buccal and palatal bone plate were observed between the two groups. The histological analysis showed new bone formation in the apical part of the biopsies, which, in some instances, was in direct contact with both SBC and DBBM particles. The coronal part of the biopsies was occupied by a dense fibrous connective tissue surrounding the SBC and DBBM particles. Conclusion: Both biomaterials partially preserved the width and the interproximal bone height of the alveolar ridge. To cite this article:
Mardas N, Chadha V, Donos N. Alveolar ridge preservation with guided bone regeneration and a synthetic bone substitute or a bovine‐derived xenograft: a randomized, controlled clinical trial.
Clin. Oral Impl. Res. 21 , 2010; 688–698.     

Synthetic polymeric barrier membrane associated with blood coagulum,human allograft,or bovine bone substitute for ridge preservation: a randomized,controlled, clinical and histological trial

During the normal healing process, an extraction site may lose significant bone volume, making implant placement problematic. Quantitative evaluations of the amount of bone maintained by socket preservation with various materials are limited. The objective of this study was to evaluate, both clinically and histologically, the extent of alveolar bone preservation by blood coagulum (BC) and the potential additional benefits of bone allograft material (AL) versus the state-of-the-art bovine bone mineral (BB), covered by a polyethylene glycol (PEG) barrier, in extraction socket grafting procedures. Adult patients (n = 32) with single-rooted teeth indicated for extraction were treated (45 sites). After atraumatic extraction, the sockets were filled with BC, AL, or BB and covered with a synthetic PEG barrier membrane. Changes in bone height and width were measured clinically and the amount of bone formed and residual graft particles were measured histologically after 6 months. Changes in ridge width at 6 months were ?1.5 mm for AL versus ?2.5 mm for BB and ?2.3 mm for BC. New bone formation amounted to 47.8%, 33.3%, and 28.2% at BC-, AL-, and BB-treated sites, respectively. Using AL with the PEG barrier preserved the ridge width at 6 months better than BB or BC and resulted in similar amounts of bone histologically to BB.     

Mandibular bone harvesting for alveolar reconstruction and implant placement: subjective and objective cross-sectional evaluation of donor and recipient site up to 4 years

Aim: To evaluate the long‐term morbidity of intraoral bone harvesting from two different donor sites (mandibular symphysis or ramus) for bone augmentation procedures before or at the time of implant placement and to evaluate the success and the survival rates of implants placed in sites augmented with mandibular bone. Methods: Seventy‐eight patients who received mandibular bone grafts were recalled after 18–42 months follow‐up (mean 29 months). The group consisted of 36 men and 42 women aged between 18 and 68 years old at the moment of augmentation surgery. Vitality of teeth adjacent to the harvesting sites was investigated. Soft tissue superficial sensory function was assessed by the Pointed‐Blunt Test and the Two‐Point‐Discrimination Test. Implant health status was assessed measuring peri‐implant probing depth and bleeding on probing. Implant survival and success rates were also calculated. In order to evaluate patients' perception of the morbidity of the procedures, the patients were asked to answer several questions by means of visual analogue scales (VAS). Results: Only two teeth (out of 282) in the chin harvesting group needed root canal treatment after surgery. A higher frequency of minor temporary and permanent sensorial disturbances was found in the group of patients who received chin harvesting procedures (2.3% vs. 13%P=0.03), while pain during chewing and bleeding were more frequently recorded after ramus harvesting (9.8% vs. 0%P=0.03). No permanent anesthesia of any region of the skin was reported. Implants' survival and success rate were comparable to implants placed in bone reconstructed with other techniques and were not influenced by the choice of the donor site. Patient's perception regarding the morbidity of the procedures was very low and did not differ between ramus and chin harvesting groups (mean VAS scores <4). Conclusion: The present cross‐sectional retrospective study demonstrated the safety of mandibular grafts that reported excellent results in terms of implant success and survival rates with minor complications regarding the donor site area. When the chin was chosen as donor site, minor sensorial disturbances of mucosa and teeth were recorded. The majority of these disturbances were temporary; only few of them were permanent but still had no impact on patient's life. To cite this article:
Cordaro L, Torsello F, Miuccio MT, Mirisola di Torresanto V, Eliopoulos D. Mandibular bone harvesting for alveolar reconstruction and implant placement: subjective and objective cross‐sectional evaluation of donor and recipient site up to 4 years.
Clin. Oral Impl. Res. 22 , 2011; 1320–1326.
doi: 10.1111/j.1600‐0501.2010.02115.x     

Long-term results and survival rate of implants treated with guided bone regeneration: a 5-year case series prospective study

One of the key factors for attaining osseointegration is the presence of an adequate osseous volume. In patients with inadequate osseous width or height, a bone augmentation using the guided bone regeneration (GBR) concept may be applied either with a simultaneous or a staged approach. The aim of this multicenter prospective case series study was to evaluate the efficacy and predictability of the GBR technique (simultaneous approach) in patients with peri-implant osseous defects, both dehiscences and fenestrations. Results 5 years post-treatment (survival rates and marginal bone level) were assessed. A total of 19 consecutive patients with 26 peri-implant osseous defects (20 dehiscences and six fenestrations) were treated during the period from September 1992 to June 1993 with a simultaneous GBR approach using non-resorbable membranes combined with autogenous bone grafts or decalcified freeze-dried bone allograft. The mean osseous augmentation was 94.8%. Marginal bone levels at re-entry and 5 years after surgery were calculated from standardized periapical radiographs. One implant was lost 3 months after loading. Thus, the cumulative survival rate was 96.1% after 5 years. The mean marginal bone level after 5 years was 2.03 mm (SD=+/-0.5), without a difference between mesial and distal sites. This study demonstrates that implants with peri-implant defects that are treated with GBR had similar survival rates and crestal bone levels compared with implants in native bone.     

External inflammatory and replacement resorption of luxated, and avulsed replanted permanent incisors: a review and case presentation

Abstract –  External inflammatory resorption and replacement resorption are complicating factors that may result from traumatic dental injuries when the tooth is luxated or avulsed and replanted. Resorption may, ultimately, result in loss of the tooth. However, with appropriate treatment, the prognosis for these teeth is greatly improved, with the possibility of preventing or arresting resorption. The purpose of this paper is to review these trauma entities, to discuss factors that influence the occurrence of resorption and to describe the most appropriate treatment. A case is presented, illustrating both resorption entities, but with varying outcomes.