Changes in contour of the maxillary alveolar process under immediate dentures. A longitudinal clinical and x-ray cephalometric study covering 5 years

A comparative analysis of particulate bovine bone substitutes for oral regeneration: a narrative review

PURPOSE

Particulate bovine bone substitutes (BS) are commonly used in oral regeneration. However, more literature is needed focusing on comparative analyses among various particulate bovine BS. This study evaluates pre-clinical and clinical data of different particulate bovine BS in oral regeneration.

METHODS

A narrative review was conducted by screening the PubMed database Included in the review were pre-clinical and clinical studies until 2024 comparing a minimum of two distinct particulate bovine BS. In addition to examining general data concerning manufacturing and treatment processes, biological safety, physical and chemical characteristics, and graft resorption, particular emphasis was placed on assessing pre-clinical and clinical data related to ridge preservation, sinus floor elevation, peri-implant defects, and various forms of alveolar ridge augmentation utilizing particulate bovine BS.

RESULTS

Various treatment temperatures ranging from 300 to 1,250 °C and the employment of chemical cleaning steps were identified for the manufacturing process of particulate bovine BS deemed to possess biosecurity. A notable heterogeneity was observed in the physical and chemical characteristics of particulate bovine BS, with minimal or negligible graft resorption. Variations were evident in particle and pore sizes and the porosity of particulate bovine BS. Pre-clinical assessments noted a marginal inclination towards favorable outcomes for particulate bovine BS subjected to higher treatment temperatures. However, clinical data are insufficient. No distinctions were observed regarding ridge preservation, while slight advantages were noted for high-temperature treated particulate bovine BS in sinus floor elevation.

CONCLUSIONS

Subtle variances in both pre-clinical and clinical outcomes were observed in across various particulate bovine BS. Due to inadequate data, numerous considerations related to diverse particulate bovine BS, including peri-implant defects, must be more conclusive. Additional clinical studies are imperative to address these knowledge gaps effectively.

Comparative Evaluation of Different Alveolar Ridge Width Measurement Techniques in Dental Implant Treatment Planning: An in Vivo Observational Non-Interventional Study

In todays era dental implant has become the dependable therapeutic treatment for the replacement of missing teeth. The success of dental implants depends not only on osteointegration of the implant but also on the surrounding hard and soft tissue. Presurgical evaluation of alveolar ridge width and height is of paramount important for implant placement. There are several methods to evaluate the alveolar ridge width and height such as ridge mapping and CBCT. This study included 30 sites from 8 patients in the age ranging from 30 to 65 years. A stent was prepared and the width of the alveolar ridge was estimated employing the following techniques: Group I: Measurement of alveolar ridge width on cone-beam computed tomography (CBCT) method, group II: Measurement of alveolar ridge width by ridge mapping technique, group III: Measurement of alveolar ridge width by surgical exposure. The minimum value for ridge mapping with caliper is 2 and maximum value is 9 with mean 4.5667 ± 1.63335 with standard error 0.29821. The minimum value for Cone beam computed tomography (CBCT) is 1.80 and maximum value is 9.30 with mean 4.6233 ± 1.67119 with standard error 0.30512. The minimum value for direct intrasurgical measurement with caliper is 2 and maximum value is 9 with mean 4.2000 ± 1.58441 with standard error 0.28927. Cone beam computed tomography could also be used to measure the ridge width accurately. Apart from measurement of alveolar ridge dimensions it had multiple other uses and thus can be advised as per requirement of the clinician.

Comparative Evaluation of the Crestal Bone Level Around Pre- and Post-loaded Immediate Endoosseous Implants Using Cone-Beam Computed Tomography: A Clinico-Radiographic Study

Introduction  Dental implants replace missing teeth. Dental implants are surgically placed tooth root replacements that secure prosthetic teeth and bridges. Branemark's original dental implant technique included a mesiobuccal flap and a two-stage approach, needing 6-8 months of recovery following extraction, sterile conditions, machined titanium implants, 3-6 months without stress for osseointegration, and a detachable temporary prosthesis. The restoration would usually be ready a year following the implant surgery. Implant treatment seeks the best function, aesthetics, and complication risk. Implant therapy with low patient morbidity and fast extraction-to-restoration times is a secondary target. Instantaneous implant insertion has made implant dentistry more convenient for patients and clinicians. This study measures bone height before, after, and one month after implant placement using cone-beam computed tomography (CBCT). Materials and Methods Participants were selected from oral evaluation candidates. This investigation included 11 people missing front maxillary or mandibular teeth or root components. Diagnostic castings determined the interarch connection before surgery. Alginate maxillary and mandibular arch imprints were cast in Type III dental stone for diagnosis. CBCT scans were taken pre-operatively, post-implant, and post-prosthesis. After the tooth was removed, the empty socket was cleaned up with curettes. An intraoral periapical radiograph and manual probing were done to determine the implant's size. The implant was removed for examination after three months, and healing abutments and gingival formers were placed. Finally, fins were placed. The CBCT images also captured the bone height around the implants. The soft tissue parameters were recorded and evaluated at baseline and one-month following prosthetic loading as plaque index (PI). Radiographic evaluation was done at baseline and one-month following functional loading using CBCT. After one month following functional loading, crestal bone levels were measured again with the help of CBCT using Image J software (National Institutes of Health, Bethesda, Maryland, US). Results The sample population had an average age of 42.81 years, with a standard deviation of 13.44 years. Using a paired t-test, we found that the mean PI dropped significantly from pre-loading levels to one-month post-loading levels, with a p-value of less than 0.001. The mean crestal bone level (mesial) evaluated by CBCT at baseline and one-month post-loading was 2.52 ± 1.97 mm and 1.17 ± 1.31 mm, respectively. The mean difference between mean crestal bone loss (distal) at baseline and one-month post-loading was 0.94 ± 1.89 mm, which was not statistically significant. The mean difference between mean crestal bone loss (buccal) at baseline and one-month post-loading was 1.82 ± 1.60 mm, which was statistically significant. The mean difference between mean crestal bone loss (lingual) at baseline and one-month post-loading was 1.91 ± 1.53 which was statistically significant. Conclusion CBCT provides all the diagnostic data needed for implant placement; hence, it is recommended.

Current perspectives of residual ridge resorption: Pathological activation of oral barrier osteoclasts

PURPOSE

Tooth extraction is a last resort treatment for resolving pathological complications of dentition induced by infection and injury. Although the extraction wound generally heals uneventfully, resulting in the formation of an edentulous residual ridge, some patients experience long-term and severe residual ridge reduction. The objective of this review was to provide a contemporary understanding of the molecular and cellular mechanisms that may potentially cause edentulous jawbone resorption.

STUDY SELECTION

Clinical, in vivo, and in vitro studies related to the characterization of and cellular and molecular mechanisms leading to residual ridge resorption.

RESULTS

The alveolar processes of the maxillary and mandibular bones uniquely juxtapose the gingival tissue. The gingival oral mucosa is an active barrier tissue that maintains homeostasis of the internal organs through its unique barrier immunity. Tooth extraction not only generates a bony socket but also injures oral barrier tissue. In response to wounding, the alveolar bone socket initiates regeneration and remodeling through coupled bone formation and osteoclastic resorption. Osteoclasts are also found on the external surface of the alveolar bone, interfacing the oral barrier tissue. Osteoclasts in the oral barrier region are not coupled with osteoblastic bone formation and often remain active long after the completion of wound healing, leading to a net decrease in the alveolar bone structure.

CONCLUSIONS

The novel concept of oral barrier osteoclasts may provide important clues for future clinical strategies to maintain residual ridges for successful prosthodontic and restorative therapies.

Immediate flapless implant placement in a smoker patient: A challenge for optimum aesthetics and secondary stability: A case report

The objective of this case report was to restore the young patient with missing teeth and extruded tooth using an immediate implant and synthetic bone graft material for the esthetic and comfort purpose. A 21-year young man reported extrusion of a tooth as well as missing teeth. Clinical examination revealed missing teeth in relation to (irt) 11 and 21, extrusion of tooth in relation to (irt) 12, patient had generalized fluorosis, and localized marginal gingivitis with melanin pigmentation. The patient is a known smoker, and he was advised the cessation of smoking before the treatment. This paper describes a step-by-step approach to different treatment phases, starting with surgical guide fabrication, immediate implant surgical procedures, bone grafting procedure, and later prosthesis fabrication. Follow-up resulted in a satisfactory outcome.

Radiographic evaluation of a bone substitute material in alveolar ridge preservation for maxillary removable immediate dentures: A randomized controlled trial

STATEMENT OF PROBLEM

Maxillary bone resorption after multiple extractions can jeopardize the success of an immediate denture, but whether bone volume preservation techniques are effective is unclear.

PURPOSE

The purpose of this randomized controlled trial was to evaluate the efficacy of socket grafting with a xenogenic bone substitute in participants receiving maxillary immediate removable complete dentures in terms of bone volume preservation (height and width of the bone ridge).

MATERIAL AND METHODS

The study was a single-blinded, randomized controlled clinical trial with 2 balanced parallel arms. Thirty-six participants who had Kennedy Class I edentulous posterior areas bilaterally for at least 3 months and required maxillary immediate removable complete dentures were enrolled. Duplicates of the removable complete denture were made and converted into radiographic and surgical guides. Participants allocated to the test group received deproteinized bovine bone mineral blended with 10% porcine collagen (DBBM-C) in the extraction sockets, and participants in the control group received no grafting material. With a radiographic guide in place, cone beam computed tomography scans were made 10 days after tooth extraction, when the immediate removable complete denture was delivered (D10, baseline), after 3 months (D90), and after 1 year (D365). The scans were superimposed, and measurements were made on the cross-sectional plane of each extraction site. The influence of various prognosis factors associated with bone volume preservation, including the location of tooth extraction, smoking habits, periodontal disease, and operator team, were analyzed.

RESULTS

Of 36 participants, 3 were lost to follow-up. The mean ±standard deviation loss of height of the buccal crest was 1.2 ±1.8 mm in the control group and 0.3 ±1.2 mm in the test group after 3 months of healing (P<.001) and 2.1 ±2.0 mm in the control group and 0.7 ±1.4 mm in the test group after 1 year of follow-up (P<.001). Mean ±standard deviation horizontal ridge width change was 1.3 ±1.4 mm in the control group and 0.5 ±0.8 mm in the test group after 3 months (P<.001) and 2.2 ±1.4 mm in the control group and 0.9 ±1.1 mm in the test group after 1 year of follow-up (P<.001). None of the other prognostic factors had a significant effect at either time period.

CONCLUSIONS

Grafting DBBM-C into the extraction socket after removing anterior teeth for immediate removable denture therapy resulted in significantly less vertical buccal crest and horizontal ridge resorption as compared with spontaneous socket healing after 1 year of follow-up. This procedure may be useful for preserving bone, especially when a fixed implant-supported prosthesis is planned.

Potential of Using an Implant Fixture as a Ridge Expander for Minor Ridge Augmentation: An Ex Vivo Randomized Controlled Study

To place implants with minimal trauma is what the patient and clinician are seeking. Hence, the aim of this study was to quantify the potential of using an implant fixture as a ridge expander in an underprepared osteotomy. Thirty-eight edentulous sites in 12 human cadaver jaws with ridge widths ranging from 4 to 6 mm and with type 3 or type 4 bone density were randomly assigned into 2 groups. In the ridge expansion group (RE), each osteotomy was drilled to a width of 2.8 mm and depth of 11.5 mm. In the non-ridge expansion (NE) control group, each osteotomy was drilled to a width of to 3.4 mm and depth of 11.5 mm. A 3.7 mm × 11.5 mm tapered implant was inserted into each site. The ridge width before (RW1) and after (RW2) implant placement as well as the buccal plate thickness (BPT) post-insertion were measured and analyzed. In the RE group, the average RW1 and RW2 were 4.69 ± 0.45 mm and 5.54 ± 0.35 mm, respectively, corresponding to a statistically significant ridge expansion of 0.85 mm (P < .01). In the NE group, no ridge width gain was observed (RW1: 4.79 ± 0.40 mm, RW2: 4.88 ± 0.42 mm). Compared to NE, RE resulted in a statistically greater BPT (1.08 ± 0.28 mm after RE vs 0.71 ± 0.37 mm after NE, P < .001). Our study determined that it was physically possible to widen a ridge by an average of 0.85 mm by osteotomy underprepation in ridge with type 3 or type 4 bone density, which effectively turned the implant upon insertion into a ridge expander. The physiological consequences of this method of ridge expansion in a living person must be established before drawing further conclusions about its clinical indications or efficacy.

On marginal bone level changes around dental implants

BACKGROUND

Peri-implant bone level values have been used as the clinical standard of reference to describe the status of a dental implant, despite the fact that their significance for the long-term survival of the implant has never been properly assessed.

PURPOSE

To challenge the assumption that the natural course of peri-implant bone loss is the loss of the implant.

MATERIALS AND METHODS

This article is a narrative review on reasons and interpretations of marginal bone level changes around dental implants.

RESULTS AND CONCLUSIONS

Different views regarding the pattern and progression of marginal bone loss depending on dental specialties have been identified. However, the present finding of a negative correlation between an increasing cumulative marginal bone loss and a decreasing risk of implant failures over time indicates that peri-implant marginal bone loss does not necessarily represent a condition of disease. Reduction of marginal bone levels may be observed in a majority of patients during follow-up time, with only a minority of those patients losing implants and implant-supported prostheses in the long term. Bone level changes seem often to occur as a consequence of physiological processes and/or as an adaptation to altered external as well as host response factors. Periodical radiological assessments of implant-restorations remain a valid diagnostic tool for the detection of potential implant fractures, loss of osseointegration, screws working loose and for the detection of the few cases with advanced, continuously progressing marginal bone loss during time. The detection of peri-implant marginal bone loss at one time point should not be immediately considered as a sign of ongoing pathology and of an increased risk of future loss of the implant in question.

Three-dimensional observations of the incisive foramen on cone-beam computed tomography image analysis

Purpose

The purpose of this study was to utilize cone-beam computed tomography (CBCT) image analysis to obtain anatomical information related to the morphology of the incisive foramen to provide useful data regarding implant placement and clinical procedures such as anesthesia.

Methods

The study included 167 patients who underwent CBCT scans over 20 years. Three components were measured: 1) the anteroposterior and mediolateral diameter of the incisive foramen, 2) the horizontal bone thickness anterior to the incisive foramen, and 3) the vertical bone height coronal to the incisive foramen. All measurements were expressed as mean±standard deviation and were analyzed by a single examiner.

Results

The anteroposterior diameter of the incisive foramen was wider than the mediolateral diameter (P<0.001). The diameter of the incisive foramen in patients in whom the central incisors were present was smaller than that in those in whom at least one central incisor was absent, but no statistically significant difference between the groups was observed. The horizontal bone thickness in the patients with central incisors was statistically significantly larger than that in the patients without at least one central incisor (P<0.001). The same pattern was observed with regard to vertical height, but that difference was not statistically significant.

Conclusions

The buccal bone thickness anterior to the incisive foramen was significantly decreased after central incisor loss. It is necessary to identify the morphology of the bone and the location of the incisive foramen via CBCT to avoid invasion of the incisive foramen and nasopalatine canal.

Preservation of Dental Sockets Filled with Composite Bovine Bone. A Single-Blind Randomized Clinical Trial

Abstract The purpose of this study was to evaluate the preservation of alveolar dimensions in human fresh extraction sockets filled with a composite bovine bone graft by means of design of single-blind randomized clinical trial. Forty participants had monoradicular teeth extracted (one teeth in each participant), and after were randomly divided into 2 groups: individuals whose fresh sockets were filled with the composite heterologous bone graft (Biomaterial Group), or with blood clot (Control Group). After extraction, the fresh sockets were measured at their greatest mesiodistal (MD) and bucco-lingual/palatal (BL/P) distance. Primary closure of the soft tissue was performed with a fibro-mucosal plug. After 120 post-operative days, the re-entry procedure was performed and the largest MD and BL/P measurements were again obtained to calculate the remodeling of the alveolar bone measured in percentage. In the biomaterial group, a percentage reduction of 1.62% and 3.29% in the MD and BL/P dimensions was observed 120 days after the extractions, whereas a reduction of 4.97% and 7.18% in the MD and BL/P dimensions occurred in the control group. There was a statistically significant difference (p<0.05) between the two groups for the bucco-palatal and mesiodistal measurements in the maxilla. In view of the results obtained, it can be concluded that composite bovine bone graft limited but did not impede alveolar bone remodeling.

Implant Placement into the Nasopalatine Foramen: Considerations from Anatomical and Surgical Point of View

Implant placement is a challenge in the anterior maxilla if the available bone is reduced and esthetics is challenging. The ideal implant position should be considered in all three dimensions: mesiodistal, apicocoronal, and orofacial. This article includes a review and a case report for the anatomical and clinical perspective of implant placement in nasopalatine foramen (near incisal canal). In this case report, the edentulous space is mutilated in between the area #12 and #21 teeth. Therefore, only one, 3.0 W/10.00 L implant (bone size 4.2 mm width and 11 mm length) could be placed. Radiographically, D2 bone quality was diagnosed. Before surgery, an emphasis was given over the proper implant selection to avoid oversized implants due to critical anatomical landmark. Careful and with minimal trauma, the soft tissue was handled and implant placement was performed in a proper position, using information from panoramic radiograph, 3-D Dentascan. A surgical guide was used for placement of the implant. Finally, immediate loading of temporary implant prosthesis was done. The primary outcome was satisfactory, as after 72 h, no swelling and numbness were reported. The patient has been recalled after healing period of 24 weeks for permanent restoration.

New bone formation by orthodontic tooth movement for implant placement

Bone defects at the anterior regions of the jaws often cause esthetic problems such as gingival disharmonies and longer crowns than neighboring teeth. Variety of procedures can be used in this region for achieving sufficient bone volume with or without different bone graft materials. All of these procedures has their own advantages and disadventages. New bone formation was defined with orthodontic tooth movement in different regions. In this case we present the use of orthodontic tooth movement, for achieving sufficient bone volume, in anterior maxillary region, for esthetic and functional results.

Full arch rehabilitation in severe maxillary atrophy with palatal approach implant placement: a case report

PURPOSE

The edentulous severely atrophic maxilla, as consequence of alveolar bone resorption and pneumatisation of the maxillary sinus, represents a serious limitation to the implant rehabilitation. Implants insertion via palatal approach (PA), in combination with relatively minimally invasive techniques aimed at increasing bone volume without the use of autologous bone harvesting is a valid alternative among the options for the rehabilitation of the upper jaw.

CLINICAL CASE

In a 70-year-old female, with a severe maxillary atrophy, 6 spiral taper implants were placed with the PA, combined with the bilateral transcrestal elevation of both the sinus floors and nasal cavities; a further GBR, with resorbable pericardium membrane covering a termoplastic allograft associated to a xenograft, was performed. The second stage was performed after 6 months. Implant prosthetic functionalization was carried out in 4 months by placing the removable prosthesis in direct contact with the healing cup screws. After that period the case was finalized with a hybrid prosthesis. Clinical and radiographic follow-ups were carried out at 6 months and at one year after prosthetic finalization, during which no pathological signs were recorded.

CONCLUSIONS

The PA implant insertion described by the Authors, combined with bone augmentation procedures, performed in the same stage, may represent a valid and reliable solution to rehabilitate maxillary edentulous patients.

Innovative Solutions Using Zygoma Implants

The severely resorbed edentulous maxilla presents significant treatment challenges. The introduction of remote implant support using zygoma implants has provided a plethora of treatment possibilities for many patients. This article presents four very different sets of circumstances successfully treated using this protocol.

Correlation between the size of the incisive papilla and the distance from the incisive papilla to the maxillary anterior teeth

Background/purpose

The incisive papilla remains relatively constant in position and is frequently used as an anatomic landmark for anterior teeth. Several attempts have been made to use the incisive papilla as guides to arrange maxillary anterior teeth for edentulous patients. The aim of the present study was to determine the relationship between maxillary anterior teeth and the incisive papilla, while comparing the findings with the classical estimate value.

Materials and methods

Horizontal distances between the labial surface of the central incisors and the incisive papilla [the distance from the labial surface of the central incisors and the posterior border of the incisive papilla (CPIP), the distance from the labial surface of the central incisors and the anterior border of the incisive papilla (CAIP), and the distance from the labial surface of the central incisors and the center of the incisive papilla (CCIP)] and the size of the incisive papilla (SIP) were measured by a digital caliper on the stone casts formed for 103 dentate persons. The Pearson correlation coefficient was used to investigate and quantify the correlation, while simple linear regression analyses were conducted to determine the strength of the association between the variables (α = 0.05).

Results

Pearson correlation coefficients for SIP and the distance between the labial surface of the central incisors and the incisive papilla (CPIP, CAIP, and CCIP) were significant (P < 0.05). A simple linear regression analysis of the data was performed, which showed that SIP contributed significantly to the prediction of the distances between the labial surface of the central incisors and the incisive papilla (CPIP and CCIP; P < 0.05).

Conclusion

Using regression methods within the population tested, it was determined that the distance between the labial surface of the central incisors and the incisive papilla could be predicted by the size of the incisive papilla.

Efficacy of bone substitute material in preserving volume when placing a maxillary immediate complete denture: study protocol for the PANORAMIX randomized controlled trial

BACKGROUND

Bone preservation is an essential issue in the context of last teeth extraction and complete edentulism. The intended treatment, whether a complete denture or an implant placement, is facilitated with a voluminous residual ridge. Bone resorption after multiple extractions has not been as well studied as the bone resorption that occurs after the extraction of a single tooth. Recent advances in bone substitute materials have revived this issue. The purpose of this study is to evaluate the interest in using bone substitute material to fill the socket after last teeth extraction in a maxillary immediate complete denture procedure compared with the conventional protocol without socket filling.

METHODS/DESIGN

A randomized, controlled, clinical trial was designed. The 34 participants eligible for maxillary immediate complete denture were divided into two groups. Complete dentures were prepared despite persistence of the last anterior teeth. The control group received a conventional treatment including denture placement immediately after extractions. In the experimental group, in addition to the immediate denture placement, a xenograft bone-substitute material (Bio-Oss Collagen®) was placed in the fresh sockets. The primary outcome of the study is to compare mean bone ridge height loss 1 year after maxillary immediate complete denture placement, with or without bone-substitute material, in incisor and canine sockets. The secondary outcomes are to compare the average bone ridge height and width loss for each extraction site. An original quantitative evaluation method using cone beam computed tomography was designed for reproducible measurements, with a radio-opaque denture duplicate. Two independent operators perform the radiologic measurements.

DISCUSSION

The immediate complete denture technique limits bone resorption in multiple extraction situations and thus allows better denture retention and better options for implant placement. To compare the benefit of using any bone socket-filling material, we proposed a quantitative evaluation protocol of resorption in the specific case of the last anterior maxillary teeth extraction with immediate denture placement.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02120053 . Registered on 18 April 2014.

A histologic, histomorphometric, and radiographic comparison between two complexes of CenoBoen/CenoMembrane and Bio-Oss/Bio-Gide in lateral ridge augmentation: A clinical trial

BACKGROUND

Several grafting materials have been used for alveolar ridge augmentation. The literature lacks researches to compare CenoBone to other grafting materials. The aim of this study was to compare CenoBone/CenoMembrane complex to Bio-Oss/Bio-Gide complex in lateral alveolar bone augmentation in terms of radiographic, histologic, and histomorphometric parameters.

MATERIALS AND METHODS

In this randomized controlled trial, ten patients who needed lateral ridge augmentation were selected and augmentations were done using either of CenoBone/CenoMembrane or Bio-Oss/Bio-Gide complexes. In the re-entry surgery in 6 months following augmentation, core biopsies were taken and clinical, radiographic, histologic, and histomorphometric evaluations were performed.

RESULTS

No statistically significant difference was seen between groups except for the number of blood vessels and percentage of residual graft materials.

CONCLUSION

CenoBone seems to present a comparable lateral ridge augmentation to Bio-Oss in.

Key aspects on the use of bone substitutes for bone regeneration of edentulous ridges

OBJECTIVES

To review the histological and clinical outcomes of the use of bone substitues in different oral bone regenerative procedures: socket preservation, immediate implant placement, lateral and vertical bone augmentation.

METHODS

Histological animal studies and clinical trials regarding the performances of bone substitutes, either allogenic, xenogeneic or alloplastic, have been evaluated. Different procedures examined separately and evidence-based results were provided.

RESULTS

The use of deproteinized bovine bone mineral (DBBM) seems to be effective most clinical indications, due to their osteoconductivity, space maintenance characteristics and slow resorption. The combination of Hydroxyapatite and Beta Tricalcium Phospate (HA/TCP) has also reported similar histological evidence and clinical outcomes. The use of autogenous block grafts is still the method of choice in clinical situations in need of vertical bone augmentation.

CONCLUSIONS

The use of bone substitutes is the standard of therapy in current modalities of lateral bone augmentation, mainly when used in conjunction with implant placement.

2-Dimensional changes of the soft tissue profile of augmented and non-augmented human extraction sockets: a randomized pilot study

AIM

This study identified the soft tissue changes of the alveolar ridge at different time points within 12 weeks after tooth extraction with and without socket augmentation.

MATERIALS AND METHODS

In 38 patients with single tooth extractions, 40 sockets were augmented and 39 extraction sockets were not augmented. At 2, 4, 6, 8 and 12 weeks impressions were taken and casts digitized with a laser scanner. The horizontal and vertical changes were compared between augmented and non-augmented sites. A p-value <0.05 was considered statistically significant.

RESULTS

The mean changes of augmented sockets were between 0.4 mm (2 weeks) and 0.8 mm (12 weeks). In non-augmented sockets changes of 0.7 mm (2 weeks) and of 1.0 mm (12 weeks) were demonstrated. The mean values differed significantly between the buccal and oral region (p < 0.01). Overall, there were significant differences of the mean dimensional changes regarding time (p < 0.01) and augmentation (p < 0.01).

CONCLUSIONS

Augmented sockets showed less resorption within 4 weeks after extraction compared to non-augmented sockets. Non-augmented sockets showed a continuous dimensional loss with a great variation over 12 weeks whereas augmented sockets had the highest degree of resorption between 4 and 6 weeks. At 12 weeks a comparable resorption in augmented and non-augmented sockets was observed.

The contribution of subsistence to global human cranial variation

Diet-related cranial variation in modern humans is well documented on a regional scale, with ample examples of cranial changes related to the agricultural transition. However, the influence of subsistence strategy on global cranial variation is less clear, having been confirmed only for the mandible, and dietary effects beyond agriculture are often neglected. Here we identify global patterns of subsistence-related human cranial shape variation. We analysed a worldwide sample of 15 populations (n = 255) with known subsistence strategies using 3-D landmark datasets designed to capture the shape of different units of the cranium. Results show significant correlations between global cranial shape and diet, especially for temporalis muscle shape and general cranial shape. Importantly, the differences between populations with either a plant- or an animal-based diet are more pronounced than those between agriculturalists and hunter-gatherers, suggesting that the influence of diet as driver of cranial variation is not limited to Holocene transitions to agricultural subsistence. Dental arch shape did not correlate with subsistence pattern, possibly indicating the high plasticity of this region of the face in relation to age, disease and individual use of the dentition. Our results highlight the importance of subsistence strategy as one of the factors underlying the evolution of human geographic cranial variation.

On the feasibility of utilizing allogeneic bone blocks for atrophic maxillary augmentation

Purpose. This systematic review was aimed at assessing the feasibility by means of survival rate, histologic analysis, and causes of failure of allogeneic block grafts for augmenting the atrophic maxilla. Material and Methods. A literature search was conducted by one reviewer in several databases. Articles were included in this systematic review if they were human clinical trials in which outcomes of allogeneic bone block grafts were studied by means of survival rate. In addition other factors were extracted in order to assess their influence upon graft failure. Results. Fifteen articles fulfilled the inclusion criteria and subsequently were analyzed in this systematic review. A total of 361 block grafts could be followed 4 to 9 months after the surgery, of which 9 (2.4%) failed within 1 month to 2 months after the surgery. Additionally, a weighed mean 4.79 mm (95% CI: 4.51–5.08) horizontal bone gain was computed from 119 grafted sites in 5 studies. Regarding implant cumulative survival rate, the weighed mean was 96.9% (95% CI: 92.8–98.7%), computed from 228 implants over a mean follow-up period of 23.9 months. Histologic analysis showed that allogeneic block grafts behave differently in the early stages of healing when compared to autogenous block grafts. Conclusion. Atrophied maxillary reconstruction with allogeneic bone block grafts represents a reliable option as shown by low block graft failure rate, minimal resorption, and high implant survival rate.

Ridge preservation for implant therapy: a review of the literature

Healing of the extraction socket after tooth removal involves retention of the blood clot followed by a sequence of events that lead to changes in the alveolar process in a three dimensional fashion. This normal healing event results in a minimal loss of vertical height (around 1 mm), but a substantial loss of width in the buccal-lingual plane (4-6 mm). During the first three months following extraction that loss has been shown to be significant and may result in both a hard tissue and soft tissue deformity affecting the ability to restore the site with acceptable esthetics. Procedures that reduce the resorptive process have been shown to be predictable and potentially capable of eliminating secondary surgery for site preparation when implant therapy is planned. The key element is prior planning by the dental therapist to act at the time of extraction to prevent the collapse of the ridge due to the loss of the alveolus. Several techniques have been employed as ridge preservation procedures involving the use of bone grafts, barrier membranes and biologics to provide a better restorative outcome. This review will explore the evidence behind each technique and their efficacy in accomplishing site preparation. The literature does not identify a single technique as superior to others; however, all accepted therapeutic procedures for ridge preservation have been shown to be more effective than blood clot alone in randomized controlled studies.

Mechanisms of guided bone regeneration: a review

Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, Guided Bone Regeneration (GBR) is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration.

Clinical and histological evaluation of postextraction platelet-rich fibrin socket filling: a prospective randomized controlled study

OBJECTIVES

The aims were to investigate whether the use of platelet-rich fibrin membranes (PRF) for socket filling could improve microarchitecture and intrinsic bone tissue quality of the alveolar bone after premolar extraction and to assess the influence of the surgical procedure before implant placement.

MATERIAL AND METHODS

Twenty-three patients requiring premolar extraction followed by implant placement were randomized to three groups: (1) simple extraction and socket filling with PRF, (2) extraction with mucosal flap and socket filling with PRF, and (3) controls with simple extraction without socket filling. Implant placement was performed at week 8, and a bone biopsy was obtained for histomorphometric analysis.

RESULTS

Analysis by microcomputed tomography showed better bone healing with improvement of the microarchitecture (P < 0.05) in group 1. This treatment had also a significant effect (P < 0.05) on intrinsic bone tissue quality and preservation of the alveolar width. An invasive surgical procedure with a mucosal flap appeared to completely neutralize the advantages of the PRF.

CONCLUSIONS

These results support the use of a minimally traumatic procedure for tooth extraction and socket filling with PRF to achieve preservation of hard tissue.

Surgical and prosthetic rehabilitation of combination syndrome

The aim of this report is to analyze the clinical symptoms, ethologic factors, and prosthetic rehabilitation in a case of Combination Syndrome (CS). The treatment of CS can be conventional or surgical, with or without the bone reconstruction of maxilla. The correct prosthetic treatment helps this kind of patients to restore the physiologic occlusion plane to allow a correct masticatory and aesthetic function. Management of this kind of patients can be a challenge for a dental practitioner.

Morphometric analysis of maxillary alveolar regions for immediate implantation

PURPOSE

The purpose of this study was to provide an actual guideline in determining the shape, diameter, and position of the implant in immediate implantation by the measurement of the thickness of facial and palatal plate, the thickness of cortical bone on the facial and palatal plate, the diameter of the root, and the distance between the roots in the cadavers.

MATERIALS AND METHODS

The horizontal sections of 20 maxillae were measured and analyzed to obtain the average values. Resin blocks were produced and cut serially at 1 mm intervals from the cervical line to the root apex. Images of each section were obtained and the following measurements were performed: The thickness of the facial and palatal residual bone at each root surface, the thickness of the facial and palatal cortical bone at the interdental region, the diameter of all roots of each section on the faciopalatal and mesiodistal diameter, and the interroot distance. Three specimens with measurements close to the average values were chosen and 3-dimensional images were reconstructed.

RESULTS

The thickness of the facial and palatal cortical bone at the interdental region in the maxilla, the buccal cortical bone was thicker in the posterior region compared to the anterior region. The interroot distance of the alveolar bone thickness between the roots increased from anterior to posterior region and from coronal to apical in the maxilla.

CONCLUSION

In this study, the limited results of the morphometric analysis of the alveolar ridge using the sections of maxilla in the cadavers may offer the useful information when planning and selecting optimal implant for immediate implantation in the maxilla.

Ridge width gain with screw spreaders: a cadaver study

BACKGROUND

The aim of this cadaver study was to evaluate the amount of ridge expansion with screw spreaders.

METHODS

Eleven edentulous maxillae providing 20 eligible sites were used. Ridges with initial width of 3 to 6 mm were expanded using a set of 6 screw spreaders, and implants (ø3.7 × 10 mm) were subsequently placed. Ridge width at 2 mm apical to the crest was measured at the baseline, after expansion, and implant placement. Buccal plate thickness and incidence of buccal dehiscence after implant placement were measured.

RESULTS

The mean initial ridge width was 3.97 ± 0.82 mm. After the expansion, the mean ridge width increased to 4.76 ± 0.77 mm (Δ = 0.79 mm). Majority of sites (7/9 sites) with an initial ridge width of <4 mm had a buccal dehiscence after implant placement. A buccal plate thickness of ≥1 mm was consistently present in cases with an initial ridge width of ≥4.5 mm after implant placement.

CONCLUSIONS

The screw spreaders had a modest effect on ridge expansion. Their use might be limited because additional bone augmentation might be required to prevent or correct the bony dehiscence encountered in ridges <4.5 mm wide. Therefore, using this particular instrument kit for horizontal ridge augmentation is only indicated in specific cases.

Fabricating an interim immediate partial denture in one appointment (modified jiffy denture). A clinical report

An immediate denture is fabricated before all the remaining teeth have been removed. Its advantages include maintenance of a patient's appearance, muscle tone, facial height, tongue size, and normal speech and reduction of postoperative pain. The purpose of this study is to describe the use of a patient's fixed prosthesis for fabricating an interim immediate partial denture in one appointment. Occlusion, occlusal vertical dimension, and facial support are maintained during the healing period in this procedure.

The incisive papilla: a significant landmark in prosthodontics

Several investigators have studied the horizontal relationship between incisive papilla and maxillary central incisor and measured the papilla incisor distance in dentate subjects to extrapolate this distance as a guide to place maxillary central incisors in complete dentures. Based on this premise, incisive papilla is recognized as an important landmark in complete denture construction. Papilla incisor measurements were made either from the middle or posterior border of the papilla and certain ethnic and national norms have been recommended to set the central incisors in complete dentures. This study was done on Dravidian dentate subjects to relate incisive papilla to central incisors and canines and also to ascertain its shape. During its transition to the edentulous state, incisive papilla changes its shape consequent to remodeling of the alveolar bone, palatal mucosa and interdental papilla following extraction of central incisor teeth. It was found that the papilla in dentate is not always round but seen in several forms. In some it was a double papilla and in a few it was rudimentary. The center of the papilla also changes from its dentulous to edentulous state. The posterior border is a relatively stable landmark since it undergoes least change after extraction of anterior teeth.

Socket preservation with alloplast: discussion and a descriptive case

Soon after tooth extraction the bone resorption takes place reducing the height and width of alveolar ridge. This produces an altered morphology of the bone unfavorable for implant placement and implant placement becomes impossible without surgical correction. Socket grafting maintains and preserves ridge for implant placement.

Crestal bone-level changes around implants placed in post-extraction sockets augmented with demineralized freeze-dried bone allograft: a retrospective radiographic study

BACKGROUND

There is limited information regarding marginal crestal bone–level changes around implants placed in post-extraction sockets augmented with demineralized freeze-dried bone allograft (DFDBA). The aim of this study was to retrospectively compare bone-level changes around implants placed in post-extraction sockets augmented with DFDBA to implants placed in native bone.

METHODS

Records of 30 consecutive patients treated with dental implants placed in post-extraction sockets augmented with DFDBA and 30 consecutive patients with implants placed in native bone were reviewed. For each implant, the radiographs from the surgical appointment were compared to those from the last follow-up visit and evaluated regarding changes of marginal bone level over time.

RESULTS

The overall survival rate from baseline to the last follow-up visit was 100% for both groups. The mean marginal bone loss was 0.15 mm for both groups for a mean follow-up time of 12 months. There were no significant differences regarding the percentage of implants and implant surfaces demonstrating marginal bone loss.

CONCLUSION

The present study indicates implants placed in post-extraction sockets augmented with DFDBA exhibited minimal marginal bone loss similar to implants placed in native bone.

Measurement of ridge alterations following tooth removal: a radiographic study in humans

OBJECTIVE

The aim of this study was a radiographic mesiodistal analysis of the shape of the bone crest 3 months after tooth removal.

MATERIAL AND METHODS

One hundred single tooth extractions were performed on 100 patients because of orthodontic or prosthetic causes. Bite blocks were used for two radiographs: one on the day of extraction and the other after healing of the socket, 3 months later. These X-rays were used to determine: (1) the most apical distance of alveolar ridge resorption, with baseline as the line between bone-to-teeth contact (the greatest distance in bone resorption height) and (2) the mesiodistal distance (MDD) and mesial and distal angles arising after bone tissue modeling.

RESULTS

Significant differences (P<0.05) emerged between the MDDs of multiple- [8 mm, 95% confidence interval (CI): 6.09, 9.90] and single-root teeth (5.60 mm, 95% CI: 4.80, 6.50). However, mesial or distal angles or the most apical distance of alveolar ridge resorption did not differ (mean distance in height=4.32 mm, 95% CI: 3.85, 4.78; mean angle=24 degrees ).

CONCLUSIONS

In this study, the post-extraction mesiodistal bone distance between teeth adjacent to the edentulous ridge depends on the size of the edentulous space. Nevertheless, the distance does not affect the distance in bone loss height. The distance of bone resorption height reaches a balance at the midpoint, which we consider indicative of stable healing. This resorption process must be considered when placing dental implants in fresh extraction sockets, especially in aesthetic sites, because the implant surfaces could be exposed after 3 months.

Platelet rich plasma to facilitate wound healing following tooth extraction

Following tooth removal bone formation normally takes 16 weeks and may result in less than adequate volume for the necessary reconstruction. Platelet rich plasma (PRP) has been promoted as an effective method for improving bone formation. Its use is often expensive, time consuming, or not clinically convenient for the patient and/or clinician. This study examines a simple method for obtaining a "Buffy Coat"-PRP (BC-PRP) and its effect on bone healing following the removal of bilateral mandibular 3rd molars. Subtraction digital radiography and CT scan analysis were used to track changes in radiographic density at PRP treated sites in comparison to ipsilateral non-PRP treated sites. PRP treated sites demonstrated early and significant increased radiographic density over baseline measurements following tooth removal. The greatest benefit of PRP is during the initial 2-week postoperative healing time period (P < .001). During weeks 3 though 12, BC-PRP treatment resulted in significant (P < .0001) increases in bone density compared to control, but there was no significant interaction between time and treatment (P > .05). For the entire time period (0-25 weeks) PRP treatment was significant (P < .0001) and time was significant (P < .0001) but there was no significant interaction (P > .05) between the effect of PRP treatment and time. It required 6 weeks for control extraction sites to reach comparable bone density that PRP treated sites achieved at week 1. Postoperative pain, bleeding, and numbness were not significantly affected by BC-PRP application. Results suggest that this simple technique may be of value to clinicians performing oral surgery by facilitating bone regeneration following tooth extraction.