A review of the submerged-root concept

Clinical outcomes of retention of the buccal root section combined with immediate implant placement: A systematic review of longitudinal studies

INTRODUCTION

Immediate implant placement in conjunction with partial extraction therapy has been shown to result in functional osseo- and dento-integration with partial preservation of the periodontal ligament (PDL) in humans. Strategic buccal root retention for PDL preservation is a biologically driven procedure that maintains alveolar ridge dimensions and esthetics, while allowing for implant placement. The aim of this study was to conduct a systematic review of longitudinal clinical outcomes of PDL-mediated ridge preservation in conjunction with implant placement in adults, compared with conventional immediate implant placement with total extractions. The primary outcome for this study was marginal bone level (MBL) changes after strategic buccal root retention implant placement techniques.

MATERIALS AND METHODS

To address a predefined PICOS question, a systematic search of randomized clinical trials and cohort studies with at least 10 participants per group and a minimum 12-month follow-up was conducted. A two-phase systematic selection strategy, data extraction, and risk of bias assessment, was performed independently and in duplicate. Randomized trials were quantitatively analyzed in a meta-analysis.

RESULTS

Ten human studies fulfilled the predefined criteria and were included; three clinical trials and seven cohort studies, for a total of 506 patients and 587 implants. PDL-mediated implant placement of single-rooted periodontally healthy teeth was found to reduce marginal peri-implant bone loss and buccal plate changes as compared to conventional immediate implants across studies, while implant survival and success rates were comparable between the two procedures. A meta-analysis found that bone changes were significantly less when retention of the buccal root section was performed as compared to total extractions (standardized mean difference: [-4.53, -0.11]); the three clinical trials were, however, largely heterogeneous (I² : 93.1%; Q = 28.98, p < 0.001).

CONCLUSION

Strategic retention of the buccal root section has a benefit in terms of dimensional ridge stability over conventional immediate implantation when implemented in carefully selected cases of single-rooted teeth.

Comparing Dual-Zone Immediate Implant Placement and Socket Shield Technique for Ridge Width Changes in the Maxilla: A Prospective Cohort Study

PURPOSE

The aim of this prospective cohort study was to assess the facial-palatal ridge dimensional changes that occurred at 8-10 months following flapless dual-zone (DZ) immediate implant placement and socket-shield (SS) immediate placement in the maxilla.

MATERIALS AND METHODS

A total of 19 patients who received 20 implants were included, with 10 implants (MegaGen AnyRidge) placed for each treatment, DZ and SS. Cast models were made at 8-10 months after implant placement to assess the dimensional ridge changes by measuring the facial-palatal ridge width on implant sites (T) at six designated points starting from the gingival margin (0, 1, 2, 3, 5 and 7) and comparing it with the corresponding measurement on the contralateral tooth site (C).

RESULTS

All 20 implants demonstrated successful osseointegration at 8-10 months follow-up (survival rate 100%). Two out of ten cases of SS group presented with minor manageable complications of external shield exposure. DZ group showed an average of 0.3 mm facial-palatal ridge width reduction, while SS group revealed a mean gain in ridge width of approximately 0.2 mm at 8-10 months follow-up.

CONCLUSION

When comparing between two treatments, there was a significant difference in ridge width change at 8-10 months following implant placement, indicating better preservation of the ridge contour for socket shield technique.

Partial Extraction Therapy with Early Implant Placement in the Esthetic Zone: A Clinical Case Report

Immediate replacement of teeth designated for extraction is an appealing treatment rationale for both the patient and the operator. However, it has been associated with a greater risk of facial recession and compromised soft-tissue esthetics. Partial extraction therapy (PET) or synonymously socket shield technique (SST) or root membrane technique (RMT) has been proposed to conserve the facial alveolar contour and soft-tissue esthetics. In this article, a special case is described where a root membrane was used to prevent the modeling of the facial aspect of the extraction socket. Partial extraction was performed allowing the socket with the facial root membrane in situ to partially heal for 8 weeks before implant placement. Successful integration and restoration were achieved with very minimal hard- and soft-tissue changes, accentuating satisfactory esthetic results as dictated by objective esthetic assessment. PET with early implant placement may be considered a viable treatment option for selected cases.

Decoronation-induced infected alveolar socket defect rat model for ridge preservation

Current rat alveolar ridge preservation models have not been well standardized. In this study, we proposed decoronation-induced infected alveolar socket model of rat. The bilateral maxillary first molars (M1) of twenty-four rats were decoronized or extracted. After 2, 6, 10, and 14 weeks, bone and soft tissue changes at M1 and periodontal conditions of maxillary second (M2) and third molars (M3) were evaluated by micro-computed tomography and histological analysis. Additional eighteen rats with standardized size defects were grafted with Bio-Oss Collagen to compare with unmanipulated contralateral side. Decoronation preserved greater bone and soft tissue dimensions at M1, provided larger three-dimensional (3D) bone contour volume, but also promoted periodontal breakdown of M2 Histological results showed intense inflammatory cell infiltrations and severe bone resorption within M1 socket and at mesial aspect of M2. The critical dimensions to accommodate largest standardized defect at M1 were 2.2-2.3 mm at vertical bone height and 2.8-3.2 mm at alveolar crestal width. Bio-Oss Collagen could not fully preserve buccal or palatal bone height but could be beneficial in preserving ridge width in large alveolar defects. Collectively, if periodontally-involved alveolar bone defect is preferred, we suggest extracting M1 roots 6 weeks after decoronation to allow periodontitis to occur at M2. If standardized critical dimension defect is preferred, we suggest extracting M1 roots 2 weeks after decoronation, and creating defect in the middle of M1 site with size no larger than 2.7 mm diameter to its full depth.

Immediate implant placement with socket shield technique in the maxilla: a prospective case series evaluation at 1-year follow-up

Background

The aims of this case series were to investigate the clinical, radiographic, implant success, complication incidence, esthetic, and patient-reported outcomes of 10 immediately placed implants associated with the socket shield technique at 12 months post-loading and to assess the ridge width changes that occurred at 8 months following implant placement.

Methods

A total of 10 patients received 10 socket shield immediate implants (MegaGen AnyRidge). At 8 months postimplantation, casts were made to assess the ridge width changes by measuring the ridge width at the implant sites and comparing them with the corresponding measurements at the contralateral tooth site. At 12 months post-loading, clinical indices, marginal bone loss, pink esthetic score, and patient-assessed outcomes were evaluated. The mean, standard deviation and median were calculated for all continuous variables.

Results

All implants demonstrated a 100% success rate, while 2 implants presented with external shield exposure that was managed successfully. The mean marginal bone loss was 0.08 ± 0.14 mm mesially and 0.21 ± 0.23 mm distally. Esthetic evaluation yielded an average modified pink esthetic score of 8.65. A mean gain of 0.17 mm in the facial-palatal ridge width was recorded at 8 months postimplantation.

Conclusions

The socket shield technique enhanced the functional and esthetic results by preserving the alveolar bone and peri-implant soft tissues. However, this is a sensitive technique and still needs more robust evidence before it can be recommended for everyday clinical practice.

Could the socket shield technique be better than conventional immediate implantation? A meta-analysis

OBJECTIVES

The purpose of this study was to evaluate whether the clinical outcome of socket shield technique (SST) is superior to that of conventional immediate implantation (CII).

MATERIALS AND METHOD

Five electronic databases (PubMed, Cochrane, Web of Science, CNKI, and Google Scholar) were searched to identify randomized controlled trials up to June 31, 2021. Five evaluation indexes were extracted, namely, buccal bone resorption at the horizontal and vertical levels (BBH and BBV), the soft tissue recession assessed by pink evaluation scores (PES), patient satisfaction (PS), ISQ, and the success rate of implantation (SRI), to compare the superiority between SST and CII operations. All data analyses were performed using Review Manager (version 5.4).

RESULTS

Ten studies were included in this review. The sample included 388 implants, with 194 in the SST group and 194 in the CII group. Compared with the CII group, the SST group had a lower BBH and BBV (standardized mean difference (SMD), - 1.77; 95% CI, - 2.26 to - 1.28; P < 0.00001 and SMD, - 1.85; 95% CI, - 2.16 to 1.54; P < 0.00001), higher PES improvement (SMD, 2.27; 95% CI, 1.59 to 2.95; P < 0.00001), higher rate of PS (OR, 3.12; 95% CI, 1.08 to 9.04; P = 0.04), and slightly higher ISQ (SMD, 0.71; 95% CI, 0.28 to 1.15; P = 0.001).

CONCLUSIONS

Compared with CII, SST could be a better option for esthetic area implantation, but evaluation of its long-term success is still needed.

CLINICAL RELEVANCE

By comparing and analyzing the operations of immediate implant in esthetic zone, we could choose SST to effectively alleviate the absorption of bone tissue and improve the contouring of soft tissue after anterior teeth extraction, so as to achieve a more stable and superior clinical outcomes of implant in esthetic zone.

[Clinical evaluation of the socket-shield technique for immediate implantation in the maxillary anterior region]

OBJECTIVE

This study aimed to evaluate the clinical effect of the socket-shield technique in the maxillary anterior region at one year after implant placement.

METHODS

Ten patients with maxillary anterior teeth that cannot be reserved were enrolled. Implants were installed following the socket-shield technique and restored six months after the surgery. The thickness of the labial maxillary bone of the implant was compared before and one year after the surgery. At one year follow-up, the reten-tion rate of the implants, Jemt classification, and pink and white aesthetic scores were evaluated. Postoperative complications and patient satisfaction were also analyzed.

RESULTS

One year after installation, the retention rate of the implant was 100%. The thickness of the maxillary bone at the neck, central, and root section of the implant reduced to (0.27±0.21), (0.19±0.20), and (0.28±0.29) mm, respectively, compared with the values immediately after the operation. The thickness of the labial maxillary bone at the three measurement points immediately after and one year after the operation was statistically significant (P<0.05). No significant difference (P>0.05) of the difference thickness between immediate and one year after operation at the three measurement points. The pink esthetic scores of the implant prosthesis was 9.10±0.54, and the white esthetic scores was 9.00±0.63. No complications were observed, and the patients had a high degree of satisfaction.

CONCLUSIONS

The socket-shield technique could provide acceptable treatment results but cannot completely avoid the reconstruction of the labial maxillary bone of the implants. The technique exhibits favo-rable short-term aesthetic result, but its long-term clinical effect and aesthetic problems need to be further studied.

Socket Shield: A Case Report

It is fairly common to remove a severely compromised tooth and provide rehabilitation by means of an implant. Resorption of alveolar bone after extraction resulting in loss of bone height and width is an unpleasant sequelae causing difficulty in implant placement. Few procedures have been promoted to attain the required bone height and width, such as guided bone regeneration socket preservation with the use of various graft materials and barrier membranes. The disadvantages of these techniques are some amount of ridge height loss and loss of buccal/facial, ridge contour. The socket shield technique is a new method where a buccal segment of root is retained as a shield, which aids in retaining periodontal ligament on buccofacial aspect. The implant is placed (immediate placement) lingual to this shield. This maintains the alveolar ridge height and buccofacial contour, thus providing superior aesthetics. This case report shows placement of an implant in upper anterior region using this technique.

Clinical Application of the Socket-Shield Concept in Multiple Anterior Teeth

A case of rehabilitation of the upper front teeth is presented. To prevent bone resorption following extractions, a socket-shield technique on all the extracted teeth was performed. The combination of a staged extraction approach, the sequence of provisionals together with the minimal bone loss of vestibular volume, allowed solving this high aesthetic demanding case in a satisfactory way for the patient both in duration of the treatment and in its final outcome.

To assess the efficacy of socket plug technique using platelet rich fibrin with or without the use of bone substitute in alveolar ridge preservation: a prospective randomised controlled study

AIM

The purpose of this study is to evaluate the efficacy of Platelet Rich Fibrin (PRF) as a socket plug with or without use of Plaster of Paris (POP) as bone substitute to preserve the alveolar ridge post-extraction.

MATERIAL AND METHODS

A prospective randomised single blind controlled study, was conducted for 18 months from November 2014 to May 2016 on 48 patients requiring extraction. All teeth were extracted atraumatically using periotomes and luxators without raising mucoperiosteal flap. Sockets were randomly allotted to groups A, B and C. Group A sockets were chosen as control, where figure of eight suture was placed. In group B sockets, PRF obtained by centrifugation was used as a socket plug and stabilised with figure of eight suture. Group C sockets were filled with POP and then covered with PRF. The socket was then closed with a figure of eight suture. Patients were informed of need for 6 months follow-up.

RESULTS

Ninety sockets in 48 patients were subjected to our study. We found that results in the sockets where we have grafted POP showed better ridge preservation and post-operative comfort even though the difference in ridge resorption between the three groups was not statistically significant. Powered by Editorial Manager® and ProduXion Manager® from the Aries Systems Corporation.

CONCLUSION

Atraumatic extraction may minimise the post-operative pain and discomfort to patient as well as the post-extraction alveolar height and width changes. The use of PRF and/or bone substitute even though clinically contributes to better post-operative healing and minimal loss of alveolar width and height, the values were not statistically significant.

A retrospective evaluation of 128 socket-shield cases in the esthetic zone and posterior sites: Partial extraction therapy with up to 4 years follow-up

OBJECTIVES

Tooth loss results in an inevitable alveolar ridge reduction. This has established a cautionary approach to extract, wait, augment, and insert the implant, in lieu of immediate placement. However, saving the tooth or part of it whenever possible is more conservative and supports the vital periodontal tissue buccofacial to an implant. The purpose of this cases series was to report on implant survival using this technique in a large cohort of patients at mid-term follow-up.

MATERIALS AND METHODS

A private practice patient database was searched for all patients having received socket-shield treatment in conjunction with immediate implant placement. Of the results returned, 128 met the inclusion criteria of ≥12 months from date of restoration, or failing prior to definitive restoration. These patients were recalled for evaluation of the restored implants up to 4 years post-treatment.

RESULTS

Seventy immediate implants with socket-shields were placed in female patients and 58 in males, age range 24-71 (mean 39 years). The distribution of sites treated were: maxillary incisors (64%), premolars (22%), canines (14%); maxilla (89.9%), mandible (10.1%). 123/128 implants osseointegrated and survived 1-4 years following restoration (survival rate 96.1%). A combined complication rate of 25/128 implants occurred (19.5%). Five implants failed to osseointegrate and were removed. The remaining 20 complications were all managed or observed without management, with implants surviving at mid-term follow-up.

CONCLUSIONS

Notwithstanding technique sensitivity and the need for randomized control studies, this case series demonstrates that the socket-shield performs competitively when compared to implant survival rates in both conventional immediate and delayed implant placement.

Socket Shield Technique for immediate implant placement - clinical, radiographic and volumetric data after 5 years

OBJECTIVES

Implant placement immediately after tooth extraction is often accompanied by resorption of surrounding tissues. A clinical technique was developed where the buccal portion of the root is retained to preserve the periodontal ligament and bundle bone. This technique is based on animal studies showing the potential to preserve the facial tissues utilizing this approach. The purpose of this study was to gain more insight regarding the safety of the technique with regard to biological and implant-related long-term complications and to observe the clinical appearance of the peri-implant tissues. Another objective was to evaluate volumetric changes of the affected facial contours in long-term and the esthetic outcomes.

MATERIAL AND METHODS

This study is a retrospective case series of 10 consecutive patients with implant replacement between the maxillary first premolars. Impressions were made prior to extraction (t1) and 5 years post-implant placement (t2). 3D-surface scans of the casts were digitally superimposed for quantitative evaluation of alterations of the facial peri-implant tissue contours and soft tissue recessions. Additionally, clinical data were collected (PPD, BOP, peri-apical radiographs and photographs).

RESULTS

All implants healed without adverse events. Peri-implant probing revealed healthy conditions. The comparison of radiographic images showed physiologic bone remodeling at the implant shoulders. Mean tissue loss on the facial side in oro-facial direction was -0.21 ± 0.18 mm. Average recession at implants was -0.33 ± 0.23 mm and at neighboring teeth -0.38 ± 0.27 mm. Mean loss of the marginal bone level at the implant shoulder amounted to 0.33 ± 0.43 mm at the mesial and 0.17 ± 0.36 mm at the distal aspect of the implants. A mean pink esthetic score of 12 was recorded.

CONCLUSION

Volumetric analysis showed a low degree of contour changes from extraction and implant placement to the follow-ups. Mucosal recession at the implant restoration was comparable to that of the neighboring teeth. Within the limitations of this descriptive study, the socket shield technique offers reduced invasiveness at the time of surgery and high esthetic outcomes with effective preservation of facial tissue contours. This technique should not be used in routine clinical practice until a higher level evidence in the form of prospective clinical trials is available.

Fractured root tips during dental extractions and retained root fragments. A clinical dilemma?

Root tip fracture can occur during the extraction of teeth. The clinician must then decide to either leave the root fragment in situ, or to attempt its removal. A similar decision is made when retained root fragments are found incidentally on oral radiographs. The prevalence of retained root fragments is reported as 11-37%. This article aims to highlight the risk benefit matrix of the removal or retention of retained root fragments, in light of the present evidence base.

Flapless alveolar ridge preservation utilizing the "socket-plug" technique: clinical technique and review of the literature

It has been documented that after every extraction of one or more teeth, the alveolar bone of the respective region undergoes resorption and atrophy. Therefore, ridge preservation techniques are often employed after tooth extraction to limit this phenomenon. The benefits of a flapless procedure include maintenance of the buccal keratinized gingiva, prevention of alterations to the gingival contours, and migration of the mucogingival junction that are often experienced after raising a flap. The purpose of this article is to review the literature concerning flapless ridge preservation techniques with the aid of collagen plugs for occlusion of the socket. The term "socket-plug" technique is introduced to describe these techniques. The basic steps of the "socket-plug" technique consist of atraumatic tooth extraction, placement of the appropriate biomaterials in the extraction site, preservation of soft tissue architecture employing a flapless technique, and placement and stabilization of the collagen plug. A case example is presented that illustrates the steps used in this technique.

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.

The socket-shield technique: a proof-of-principle report

AIM

Clinical studies have suggested that retaining roots of hopeless teeth may avoid tissue alterations after tooth extraction. Therefore, the objective of this proof-of-principle experiment was to histologically assess a partial root retention (socket-shield technique) in combination with immediate implant placement.

MATERIAL AND METHODS

In one beagle dog, the third and fourth mandibular pre-molar were hemisected and the buccal fragment of the distal root was retained approximately 1 mm coronal to the buccal bone plate. Following application of enamel matrix derivate, a titanium implant was placed lingual to that tooth fragment either with or without contact to the buccal tooth fragment and a healing abutment was connected. Four months after implant placement, histological evaluation, and backscatter scanning electron microscopy were performed.

RESULTS

All four implants were osseointegrated without any histologic inflammatory reaction and the tooth fragment was devoid of any resorptional processes. On the buccal side, the tooth fragment was attached to the buccal bone plate by a physiologic periodontal ligament. On the lingual side of the fragment, newly formed cementum could be detected. In the areas where the implant was placed into the fragment, newly formed cementum was demonstrated directly on the implant surface.

CONCLUSIONS

Retaining the buccal aspect of the root during implant placement does not appear to interfere with osseointegration and may be beneficial in preserving the buccal bone plate.

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.

The use of panoramic radiology in dental practice

OBJECTIVES

Approximately 1.5 million panoramic radiographs are taken annually in the general dental service in England and Wales. The aim of this review was to assess the clinical role of panoramic radiology in the diagnosis of diseases associated with the teeth and to consider its value in routine screening of patients.

METHOD

This was carried out by critical review of the literature.

RESULTS

In addition to common problems with radiographic technique and processing, there are limitations in image quality inherent to panoramic radiology. These factors contribute to a reduced diagnostic accuracy for caries diagnosis, demonstration of periodontal bone support and periapical pathology when compared with intraoral radiography. Routine screening is unproductive for large proportions of dentate and edentulous populations, while in those cases where pathology is detected the diagnostic accuracy can be questioned. Furthermore, the "detection' of asymptomatic anomalies may have no effect on patient management. Attempts to develop and test panoramic radiographic selection criteria are reviewed.

CONCLUSIONS

New, high-yield selection criteria for panoramic radiography are proposed as a means of reducing unnecessary examinations, limiting radiation doses and reducing financial costs to patients and health service providers. However, research is indicated to develop further and to test such selection criteria.

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.

Mandibular overdenture treatment. Case report

Complete mandibular dentures have a significantly lower success rate compared with complete maxillary dentures. Overdentures are feasible alternatives in many instances in attempting to achieve an optimal clinical result. The case of a 56-year-old female patient requiring prosthetic rehabilitation is discussed. A complete maxillary denture and a complete mandibular overdenture were constructed.

Mandibular reconstruction with subsequent denture implantation

A 23-year-old female patient with ameloblastoma on the right side of the mandible is presented. The affected mandible was excised and reconstructed with a free vascularised scapular bone graft followed by dental reconstruction with an artificial dental root. This is a preliminary report and the benefits of the procedure are discussed.

Vital root retention. A 5-year experience

An over 5-year experience with the vital root retention procedure is presented (122 roots). Elements in case selection as well as a surgical modification are noted. Results are favorable.

Clinical evaluation of Durapatite submerged-root implants for alveolar bone preservation

A study was undertaken to evaluate the safety and efficacy of Durapatite cones as an immediate submerged-root implant in the mandibular symphysis region. The study involved 30 patients of which 15 received 96 implants and the other 15 served as controls. The clinical and radiographic results revealed the implants to be well-accepted by alveolar bone. No evidence of rejection or major complications were observed. The principal problem which occurred was dehiscence of mucosa over some implants. This problem was attributed to operative technique. There was significantly less vertical bone loss and contour change in the anterior part of mandible in the implant group than in the control group.

Panoramic radiographic examination of edentulous patients

A study of panoramic radiographs made on 114 edentulous patients was described. Six radiographic entities were identified: root fragments, retained teeth, radiolucencies, radiopacities, foreign bodies, and mental foramina at or near the crest of the residual ridge. The percent of positive findings in this study and those of previous studies support the fact that one of three edentulous patients has a potentially complicating condition within the denture base foundation. These investigations stress the necessity of radiographic examination of all edentulous patients prior to treatment with complete dentures. The high incidence of positive findings suggests not only the need for radiographic examinations of all patients, but also the frequency with which the dentist is faced with the necessity of modifying the treatment plan.

Autogenous dermal graft coverage of submerged roots in the dog

Dermal grafts were compared with conventional supraperiosteal recipient beds grafted with split-thickness skin for covering submerged vital roots in six dogs. Several potential advantages of this new technique are suggested.

The retention of vital submucosal roots under immediate dentures: a surgical procedure

An approach to soft tissue management and surgical crown/root sectioning for submucosal vital root retention has been presented. Attention to detail during soft tissue reflection, tooth sectioning, and the relaxing of attached mucogingival tissues is very important. Adequate healthy soft tissue is necessary for proper suturing over the retained roots. Postoperative complications are reduced by placement of well-fitted prostheses. Clinical evaluation of this technique has proved it to be highly successful.

Free autogenous graft coverage of vital retained roots

The use of free autogenous grafts to the alveolus during root submergence was shown to be a method that might be used to prevent the loss of masticatory mucosa and vestibular depth, which have been regarded as problems associated with the procedure.

Reevaluation of submerged vital roots

A total of eight vital roots were submerged and retained under complete dentures in two patients. Within two to three years, each patient experienced problems of pain, re-exposure, and inflammation, resulting in the removal of the roots. Histologic evaluation showed evidence of chronic inflammation of the pulpal tissue. Because of alveolar resorption and perhaps super-eruption of the submerged roots, the likelihood of exposure and abscess is a distinct disadvantage to the procedure. Therefore, some doubt remains as to the long-term success with this technique.

Submergence of roots for alveolar ridge preservation. A failure (4-year follow-up study)

A 4-year clinical and radiographic follow-up study of 20 cases of crown-resected root-filled roots, covered by mucosal flaps, distributed among 15 patients, has been carried out. Only cases of uneventful submergence of the root with intact healthy mucosa were regarded as successful. This study shows that: (1) The number of failures increases with the years; from 3 cases at the 1-year to 11 cases at the 4-year follow-up, corresponding to 53% (8/15) of the patients. In the failures, an exposure of the root-surface was seen, but without inflammation in the surrounding tissue. These roots could be extracted without bone loss. (2) Alveolar ridge atrophy is not prevented by retained roots, and is probably the primary reason for failure of coverage. The 11 failures showed alveolar ridge atrophy, which was observed before failure in 6 cases. None of the successful cases showed alveolar ridge atrophy. The present method cannot be recommended as a routine procedure.

The case against the edentulous ridge--and an alternative

Loss of alveolar bone height frequently occurs when all teeth have been extracted, and many consider this loss irreversible. Retaining teeth under complete and partial dentures is a way of preventing bone loss; this type of treatment should be considered more often to prevent the handicapping condition of edentulism.