Osteogenesis ability of CAD-CAM biodegradable polylactic acid scaffolds for reconstruction of jaw defects.

STATEMENT OF PROBLEM: Reconstruction of alveolar bony defects is difficult using grafting materials in a powder form. A biodegradable scaffold material might simplify the procedure. PURPOSE: The purpose of this in vivo study was to evaluate osteogenesis ability of a biodegradable CAD-CAM-fabricated polylactic acid (PLA) scaffold enriched with calcium phosphate salts including hydroxyapatite (HA) and beta tricalcium phosphate (ß-TCP) used to reconstruct mandibular defects in a dog model. MATERIAL AND METHODS: Surgical defects were made bilaterally in the mandible of male beagle dogs. Computerized tomography images were obtained for determination of the 3-dimensional shape of the defects after 3 months of healing. Porous PLA scaffolds were fabricated by milling custom-made CAD-CAM blocks into the desired shape. After milling, half of the scaffolds were prepared by filling the pores of the scaffolds by a mixture of HA and ß-TCP. Scaffolds were inserted in the mandibular defects bilaterally. After a healing time of 8 weeks, the bone-scaffold interface was analyzed histomorphometrically to detect the amount of new bone formation. Stained histological sections were examined using a computer software and depth of new bone formation was assessed (n=14, α=.05). RESULTS: Histomorphometric analysis revealed that enriched scaffolds with calcium phosphates had significantly (t=4.4, P<.001) higher amounts of new bone formation (1.3 ±0.33 mm) compared with the controls (0.7 ±0.39 mm). Average new bone growth in enriched scaffolds was 1.3 mm while almost half this value was observed in uncoated scaffolds, 0.7 mm. CONCLUSIONS: Within the limitations of this animal study, HA and ß-TCP enhanced osteogenesis ability of CAD-CAM-fabricated PLA scaffolds.

Analysis of marginal bone loss and implant stability quotient by resonance frequency analysis in different osteointegrated implant systems. Randomized prospective clinical trial.

BACKGROUND: The aim of the present prospective clinical study is to compare the stability of the implant-bone interface by the ISQ quotient and marginal bone loss (MBL) rate during one year of follow-up in four system implants with the same surface and different design. MATERIAL AND METHODS: Prospective randomized clinical trial of 21 patients in which four implant systems with the same surface and different design were placed. Patients were treated by the same operator following a similar surgical protocol with submerged technique. The second surgery to perform the prosthesis was performed at 3 months. All patients went to their review at 6 months and a year. A periapical radiograph for crestal bone analysis and an Implant stability quotient by resonance frequency analysis (ISQ) analysis were taken at baseline and the reviews. RESULTS: No statistically significant differences were found in the Implant stability quotient by resonance frequency analysis and Marginal Bone Loss in the four types of implants. The ISQ increased from the moment of insertion of the implant until the revision to the year, showing an increase of the stability implant, being this increasing less between the 6 months and the year. CONCLUSIONS: Differences in the design of the four implants tested in this study did not show statistically significant differences in any of the variables studied, so the implant design does not influence implant stability and marginal bone loss in the first year after placement.

Short dental implants: A scoping review of the literature for patients with head and neck cancer.

STATEMENT OF PROBLEM: Dental implants can be essential in the rehabilitation of various cancer defects, but their ideal placement can be complicated by the limited dimensions of the available host bone. Surgical interventions developed to increase the amount of bone are not all predictable or successful and can sometimes be contraindicated. Short dental implants have been suggested as an alternative option in sites where longer implants are not possible. Whether they provide a successful treatment option is unclear. PURPOSE: The purpose of this study was to review the literature on short dental implants and assess whether they are a viable definitive treatment option for rehabilitating cancer patients with deficient bone. MATERIAL AND METHODS: A scoping review of the literature was performed, including a search of established periodontal textbooks for articles on short dental implants combined with a search of PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews. A search for all literature published before June 2016 was based on the following keywords: ['dental implants' OR 'dental implantation, endosseous' OR 'dental prosthesis, implant supported'] AND [short]. RESULTS: The minimum acceptable implant length has been considered to be 6 mm. The survival rates of short implants varied between 74% and 96% at 5 years, depending on factors such as the quality of the patient's bone, primary stability of the implant, clinician's learning curve, and implant surface. Short implants can achieve results similar to those of longer implants in augmented bone and offer a treatment alternative that could reduce the need for invasive surgery and associated morbidity and be safer and more economical. CONCLUSIONS: Short dental implants (6 mm to 8 mm) can be used successfully to support single or multiple fixed reconstructions or overdentures in atrophic maxillae and mandibles. The use of short dental implants lessens the need for advanced and complicated surgical bone augmentation procedures, which reduces complications, costs, treatment time, and morbidity. Short implants could be an alternative in the rehabilitation of patients with cancer.

Satisfaction and quality of life with palatal positioned implants in severely atrophic maxillae versus conventional implants supporting fixed full-arch prostheses.

BACKGROUND: To evaluate satisfaction and quality of life in patients with palatal positioned implants supporting fixed full-arch prostheses to rehabilitate edentulous maxillae with horizontal atrophy and compare them with conventional well-centered implants placed in non-atrophic supporting fixed full-arch prostheses. MATERIAL AND METHOD: A clinical retrospective study was performed of patients that were rehabilitated with full-arch fixed implant-supported maxillary prostheses and had a minimum follow-up of 5 years after implant loading. Patients were divided into 2 groups: patients with class IV maxilla according to Cawood and Howell and treated with palatal positioned implants (test) and with class III maxilla and treated with implants well-centered in the alveolar ridge and completely surrounded by bone (control). Ten-cm visual analogue scales (VAS) (range 1-10) and the OHIP-14 (Oral Health Impact Profile) questionnaire were used respectively to estimate patient satisfaction and quality of life after implant therapy. Statistical analysis was performed applying Mann-Whitney Test using alpha set at 0.05. RESULTS: Mean global and specific satisfaction--except for self-esteem--were superior for the test group than the control group, although differences were not statistically significant. Regarding quality of life, the reported incidence of problems was lower in the test group for all the studied items except for 'problems at work'. However, differences were not statistically significant in any case. CONCLUSION: Despite the limitations of the study (retrospective and nonrandomized design) the results suggest that the prosthesis design needed to rehabilitate palatally positioned implants (more coverage of palate) does not lead to lower satisfaction and quality of life of patients, compared to patients treated with implants placed centered and conventional design prostheses that do not cover the palate.

An Intraoperative Site-specific Bone Density Device: A Pilot Test Case.

AIM: This paper reports a case of all-on-four rehabilitation where bone density at implant sites was assessed both through preoperative computed tomographic (CT) scans and using a micromotor working as an intraoperative bone density measurement device. BACKGROUND: Implant-supported rehabilitation is a predictable treatment option for tooth replacement whose success depends on the clinician's experience, the implant characteristics and location and patient-related factors. Among the latter, bone density is a determinant for the achievement of primary implant stability and, eventually, for implant success. The ability to measure bone density at the placement site before implant insertion could be important in the clinical setting. CASE DESCRIPTION: A patient complaining of masticatory impairment was presented with a plan calling for extraction of all her compromised teeth, followed by implant rehabilitation. A week before surgery, she underwent CT examination, and the bone density on the CT scans was measured. When the implant osteotomies were created, the bone density was again measured with a micromotor endowed with an instantaneous torque-measuring system. The implant placement protocols were adapted for each implant, according to the intraoperative measurements, and the patient was rehabilitated following an all-on-four immediate loading protocol. CONCLUSION: The bone density device provided valuable information beyond that obtained from CT scans, allowing for site-specific, intraoperative assessment of bone density immediately before implant placement and an estimation of primary stability just after implant insertion. CLINICAL SIGNIFICANCE: Measuring jaw-bone density could help clinicians to select implant-placement protocols and loading strategies based on site-specific bone features.

Surgical and prosthetic management of a complex edentulous patient for fabrication of complete dentures.

Fabrication of well-fitting complete dentures becomes a challenge in the presence of epulis fissuratum in the maxilla or severely resorbed alveolar tissue in the mandible. This clinical report describes the surgical and prosthetic treatment of a patient who presented with both problems. The neutral zone technique was used to improve the stability of the mandibular complete denture. Both dentures were fabricated prior to surgical excision of the epulis fissuratum and inserted immediately following the surgery.

Retrospective success and survival rates of dental implants placed with simultaneous bone augmentation in partially edentulous patients.

AIM: The aim of this study was to assess the success and survival rate of dental implants placed with simultaneous hard tissue grafting. MATERIAL AND METHODS: All patients treated in Royal Dental Hospital of Melbourne who had implant placement with and without guided bone regeneration (GBR) procedures were identified. Seventy-three attended a follow-up appointment. These patients were examined recording probing depth, bleeding on probing, plaque accumulation and radiographic bone loss by one examiner. Clinical and radiographic findings were compared in grafted and non-grafted groups and also analysed for years in function. RESULTS: Approximately 50% of implants were placed simultaneous guided bone regeneration technique. In the majority of cases, defects were filled by deproteinized bovine bone mineral and covered with collagen membrane. The range of time in function was 20-88 months with a mean 34.8 (±1.7). Seventy-nine per cent of the implants placed in anterior maxilla were placed with GBR, while only 18% in posterior mandible needed grafting procedure. The cumulative implant survival rates at the time of examination was 97.95% for both GBR and non-GBR group. The mean PPD, BOP, and Plaque index were not statistically significantly different in GBR vs. non-GBR groups two to seven years in function. However, bone loss is significantly less in GBR group 2-7 years after function. The overall success rate was around 90% after 2-7 years in function with the GBR group slightly less than the non-GBR group, but not statistically significant. CONCLUSIONS: For the subjects included in this retrospective study, the data demonstrate that GBR is a predictable procedure. The survival and success rates of the implants inserted with simultaneous GBR were similar, if slightly lower, to the non-grafted implants.

Usefulness of Wedge-Shaped Implants in the Full-Arch Rehabilitation of Severe Maxillary Atrophy: A Case Report.

The management of marked horizontal bone atrophy represents a critical challenge for traditional implantology procedures. For this purpose, clinicians have developed several protocols and procedures to allow the most suitable and accurate surgical and prosthetic implant rehabilitation. Despite the development of guided bone regeneration methods and the use of small-diameter implants, the rehabilitation of thin bone areas is a clinical dilemma for the medium- and long-term survival of implant-prosthetic therapies. This clinical case evaluates the use of wedge-shaped implants for the full-arch rehabilitation of an atrophic maxilla with a thin ridge. This treatment choice allowed a minimally invasive rehabilitation, avoiding regenerative bone surgery, while respecting biologic and prosthetic limits. Furthermore, evaluation of the implant stability quotient and marginal bone loss values during the first year of follow-up allowed analysis of the behavior of this rehabilitation in fullarch maxillary cases.

All-on-4 Concept With Use Of Zygoma Implants for Rehabilitation in the Severely Atrophied Maxilla With a Definitive Immediate Restoration.

This case report of a 45-year-old patient at initial presentation shows an illustration of the limitations of periodontal maintenance therapy and subsequent implant prosthetic therapy. In close consultation with the patient, treatment strategies were adopted to maximize the preservation of prognostically questionable teeth. Eight years later, the patient had a highly atrophied maxilla that could be successfully restored with implants. This was achieved with 2 zygoma implants and 2 anterior conventional implants, which were immediately loaded according to the All-on-4 concept and immediately provided with a definitive prosthetic restoration. The case report demonstrates to the general practitioner that using zygoma implants in such constellations may offer a solution to achieve a fixed, rapid, and financially acceptable prosthetic rehabilitation.

Hollow dentures: treatment option for atrophic ridges. a clinical report.

Severely atrophic ridges provide decreased retention, support, and stability and pose a clinical challenge to the success of complete denture prostheses. Extreme ridge resorption also increases the interridge distance. Restoration of the vertical dimension and esthetics thus demands increased height of the prosthesis and in turn leads to an increase in prosthesis weight. Reducing the weight of the denture enhances stability and retention and reduces further resorption of the jaw, thereby favoring the prognosis of the denture. This report describes the rehabilitation of an edentulous patient with resorbed maxillary and mandibular ridges and an increased interridge distance using simplified techniques of fabricating hollow dentures.

A prosthetic alternative for severely angled implants beneath a maxillary overdenture: a clinical report.

Implant-retained overdentures have been shown to be a predictable, accepted option and represent a viable and cost-effective treatment; however, patients with severe lack of bone volume and anatomical limitations are often a contraindication to the placement of osseointegrated implants without prior surgical procedures. In these situations, the placement of angled implants may offer a simple solution. This clinical report describes a case of dental rehabilitation using angled implants for a patient with a severely resorbed edentulous maxilla. The inclination has been solved by making a bar on the right side and individual pillars on the left side so as to obtain a functional and esthetic prosthetic result.

Rehabilitation of the edentulous maxilla complicated by combination syndrome with an implant overdenture: a case report.

The treatment of the edentulous jaws with complete dentures is determined individually and often is unpredictable. Implant-assisted overdentures are a significant improvement over conventional complete dentures in terms of patient comfort and function. Combination syndrome refers to a dramatic exaggeration of maxillary alveolar resorption leading to a more complicated rehabilitation. This article reviews how the edentulous maxilla can be rehabilitated with an implant-assisted overdenture. A case report is presented which utilizes a computer-aided design/computer-aided manufactured milled titanium connecting bar to retain a chrome-cobalt based, precision attachment, palateless prosthesis.

Restoration of congenitally missing maxillary lateral incisors using mini implants.

In this author's opinion, the advent of mini implants, or small diameter implants (SDIs) as they are more frequently being called, are becoming in many situations a viable alternative to the more traditional root form implants. They offer advantages of less cost, a more simplified placement technique, usually faster healing times, and generally less post-operative complications. A case presentation is given to demonstrate their usage for a narrow ridge application to restore congenitally missing maxillary lateral incisors.

Implant-supported overdentures.

Retention of the lower complete denture is always a question for the dentist and the patient because of the alveolar ridge resorption and many muscle attachments to the mandible. The treatment of edentulous patients using oral implants does not always permit the placement of an adequate number of implants for fixed prosthesis construction; the reasons are insufficient anatomical bone height of the alveolar ridge, health restrictions and financial limitations. Placement of two dental implants in the cuspid regions anterior to the mental foramina on either side will improve the retention and stability of complete dentures in edentulous patients. Implant-supported overdentures with ball and socket attachments are more successful, provide good retention, stability for the denture and improve comfort and confidence for the edentulous patient while speaking and masticating.

Long-term follow-up of severely resorbed mandibles reconstructed using tent pole technique without platelet-rich plasma.

PURPOSE: To investigate the results of edentulous patients with severely resorbed mandibles who were treated with a modified tent pole procedure. PATIENTS AND METHODS: Twenty-two edentulous patients (3 men, 19 women; mean age, 62 yr; range, 51 to 72 yr) with a history of conservative prosthodontic treatment failures were included this study. Using a transcutaneous submental approach, 4 endosseous dental implants were placed in the anterior mandible of each patient and covered with autogenous bone grafts harvested from the posterior iliac crest without the addition of platelet-rich plasma. Follow-up ranged from 3 to 9 years. RESULTS: The postoperative course of the patients was uneventful, without any surgical infections. At 3 months postoperatively, the density of the grafted bone appeared to closely resemble that of the surrounding alveolar bone on panoramic radiographs. The average alveolar augmentation was 6.3 mm (standard deviation, 1.59 mm; range, 4 to 10 mm) and long-term follow-up showed no bone resorption around the endosseous implants. CONCLUSIONS: The modified tent pole technique without the addition of platelet-rich plasma is a safe and effective method to reconstruct the severely resorbed mandible.

Rehabilitation of atrophic posterior maxilla with zygomatic implants: review.

The objective of this study was to review the published literature to evaluate treatment success with zygomatic implants in patients with atrophic posterior maxilla. Studies from 1987 to 2010 were reviewed. In each study, the following were assessed: indications for treatment, number of patients, number of implants, length and diameter of the implants, surgical technique, prosthetic rehabilitation, success rate, complications, and patient satisfaction. Sixteen studies were included, with a total of 941 zygomatic implants placed in 486 patients. The follow-up periods ranged from 12 to 120 months. Three different surgical techniques were used to place zygomatic implants: intrasinus implants with the classic sinus window technique, the sinus slot technique, and extrasinus zygomatic implants. The most common restoration used was fixed prosthesis, with either delayed loading after 3-6 months (89%-100% success) or immediate loading (96.37%-100% success). The weighted average success rate was 97.05%, and the most frequent complication was maxillary sinusitis. The general level of patient satisfaction was high. Zygomatic implants have a high success rate and constitute a suitable alternative to treat severe posterior maxillary atrophy.

Fixed rehabilitation of severely atrophic jaws using immediately loaded basal disk implants after in situ bone activation.

Rehabilitation of severely atrophic jaws is facilitated when basal disk implants are used after activation of the future bony implant bed with a purpose-designed instrument (Osteotensor) 45 to 90 days before implant surgery. Fabrication of a highly rigid, screw-secured fixed prosthesis that acts as an external orthopedic fixator permits immediate functional loading. This protocol also represents a second chance for patients who have experienced complete implant loss and/or bone graft failure.

Rehabilitation of the atrophic posterior maxilla with pterygoid implants: a review.

The purpose of this article is to review the literature published and to assess the success of treatment of patients with atrophic posterior maxilla with pterygoid implants. Studies from 1992 to 2009 on patients with atrophic posterior maxilla rehabilitated with pterygoid implants were reviewed. Those reporting clinical series of at least 5 patients with atrophic posterior maxilla (Class IV and V of Cawood and Howell), rehabilitated with pterygoid implants and fixed prosthesis, and with 12 months minimum follow-up were included. In each study the following were assessed: number of patients, number of implants, surgical technique, prosthetic rehabilitation, success rate, bone loss, complications and patient satisfaction. Thirteen articles were included, reporting a total of 1053 pterygoid implants in 676 patients. The weighted average success of pterygoid implants was 90.7%; bone loss evaluated radiographically ranged between 0 and 4.5 mm. No additional complications compared with conventional implants were found, and patient satisfaction level with the prosthesis was high. Pterygoid implants have high success rates, similar bone loss levels to those of conventional implants, minimal complications and good acceptance by patients, being therefore an alternative to treat patients with atrophic posterior maxilla. Two anatomical locations in which implants are placed in the retromolar area can be distinguished: the pterygoid process and the pterygomaxillary region. Implant lengths and angulations vary between these two techniques.

Fold-over flap technique for developing the facial gingival contour: a case report.

A dental implant surgical technique is described including a 12-mm fold-over of a facial flap and coapting the internal side of the folded flap with a 4-0 suture. The flap is pulled against a provisional crown with a sling-type suture during the implant uncovery stage and may decrease the risk for a poor esthetic facial gingival architectural outcome.

Oral rehabilitation with tilted dental implants: a metaanalysis.

OBJECTIVE: To compare the course of patients treated with tilted implants versus those treated conventionally with axial implants, analyzing the success rate and marginal bone loss. MATERIAL AND METHODS: A PubMed search was made using the key words "tilted implants ", "angled implants ", "angulated implants ", "inclined implants " and "maxillary atrophy. " A review was made of the articles published between 1999-2010. The inclusion criteria were the use of tilted implants, clinical series involving at least 10 patients, and a minimum follow-up of 12 months after prosthetic loading. The exclusion criteria were isolated clinical cases, studies with missing data, and publications in languages other than English or Spanish. The metaanalysis finally included 13 articles: 7 retrospective studies and 6 prospective studies. RESULTS: On analyzing the success rate in the retrospective studies, two reported a higher success rate with tilted implants; one a higher success rate with axial implants; and two reported similar success rates with both implants. On analyzing the success rate in the prospective studies, two reported a higher success rate with tilted implants; two a higher success rate with axial implants; and two reported similar success rates with both implants. On examining marginal bone loss, three studies reported greater bone loss with axial implants and one with tilted implants. CONCLUSIONS: There was no evidence of differences in success rate between tilted and axial implants in either the prospective or retrospective studies subjected to review. The marginal bone loss observed with the tilted and axial implants likewise proved very similar. It thus can be deduced that tilted implants exhibit the same evolutive behavior as axial implants.