Brånemark system implants in the posterior maxilla: clinical study of 660 implants followed for 5 to 12 years

Originally, osseointegrated implants were used principally in the anterior region of the mandible and maxilla, but use in the posterior segments of both arches is common today. The long-term success of implants placed in the posterior region, an environment of stronger forces and poorer bone quality, has not been thoroughly reviewed. The purpose of the present study was to review a large series of Br?nemark System implants placed in posterior maxillae (660 implants in 202 patients) that have been restored with fixed partial ceramometal restorations and followed for as long as 12 years after loading. Thirteen of the implants (2%) failed between placement and loading, 12 implants were lost between loading and the end of the first year, and 10 failed thereafter, 2 as the result of fractures at 3 and 4 years. The cumulative success rate is therefore 94.4% at 5 to 6 years and 93.4% after 10 years. The quality and quantity of bone appeared to have little influence on the success rate. Surgical techniques are particularly important to the success of osseointegrated implants placed in the posterior maxilla. With careful surgical planning and execution, a success rate of approximately 95% at 5 years can be achieved.     

Rehabilitation of totally atrophied maxilla by means of four zygomatic implants and fixed prosthesis: a 6–40-month follow-up

The zygomatic implant is an alternative to bone grafting in extremely resorbed maxilla. This study evaluates the results of a consecutive cohort of 20 patients (mean age 56 years) with extremely resorbed maxillas provided with four zygomatic implants. The first 10 patients had a two-stage procedure, the next 10 next patients benefited from a one-stage surgical procedure and one of them had flapless guided surgery with Nobelguide^® in development and immediate function. The same surgical drilling protocol, according to Branemark's procedure, was applied to all the patients. Except for one patient who lost three implants, 18 patients received a fixed Procera^® implant bridge and another an overdenture retained by a screwed bar fixed on the four zygomatic implants. The cumulative survival rate after 40 months is 96%. Although bone augmenting procedures such as onlay grafts and sinus grafts are popular and well-documented, the four zygomatic implants procedure results in less morbidity, shorter delays between anatomical reconstruction and functional rehabilitation and can provide immediate or early loading with immediate function. Four zygomatic implants and a fixed bridge seem to be a valuable technique for the rehabilitation of extremely resorbed maxillas.     

Three-dimensional measurement of radiographic bone–implant contact lengths of zygomatic implants in zygomatic bone: a retrospective study of 66 implants in 28 patients

Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone–implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1 year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80 ± 5.88 mm versus 17.79 ± 6.34 mm; P = 0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11 ± 6.23 mm versus 17.75 ± 5.85 mm; P = 0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.     

Implant treatment in the edentulous mandible: a prospective study on Brånemark system implants over more than 20 years

PURPOSE: This prospective investigation studied the clinical and radiographic performance of mandibular fixed prostheses supported by osseointegrated implants over more than 20 years. MATERIALS AND METHODS: A total of 273 standard Br?nemark implants (10 mm long) were placed in 47 patients between 1978 and 1982. Clinical and radiographic data collected at several examinations over the 20-year observation period have been reported previously. This study presents the outcome of the latest follow-up after 20 to 23 years. RESULTS: Thirty patients (64%; 75% of those still alive) attended the 20-year follow-up examination. Three implants were lost during the entire observation period, and the 20-year implant cumulative survival rate was 98.9%. All patients had continuous prosthesis function, but two had their mandibular prostheses remade during the 20 years. No implants or prostheses were lost or fractured during the last 5 years, and only a few prosthodontic complications were noted. The mean bone level was 1.6 mm (SD 0.90) below the reference point after 20 years, and mean bone loss was 0.2 mm (SD 0.22) between the 15- and 20-year follow-ups. Thirty-seven implants (24%) showed more than two exposed threads at the 15-year follow-up examination, but only four implants (3%) presented pain and/or bone loss exceeding one thread (0.6 mm) during the last 5 years. CONCLUSION: The successful treatment result after 15 years continued up to more than 20 years in function. During the last 5 years, a majority of the implants with several exposed implant threads could be maintained without any complications, and the frequency of implants showing signs of ongoing peri-implantitis was less than 3%.     

Inlay–onlay grafting for three-dimensional reconstruction of the posterior atrophic maxilla with mandibular bone

This prospective study describes and evaluates a surgical approach for 3D reconstruction of the posterior maxilla with autogenous mandibular bone in 16 patients (mean age 51 years). Bone blocks were harvested from the mandible and used as lateral or vertical block grafts (onlay); they were also partially milled and used for sinus elevation (inlay). In 4 cases, anorganic bovine bone was added at the periphery of the blocks. 4 months after grafting, implants were placed in a second operation and loaded after 12 weeks. Lateral and vertical augmentations were measured immediately after grafting and at re-entry for implant placement. Mean lateral augmentation performed was 5.5 mm, reduced to 4.3 mm (p < 0.01) after 4 months’ healing. Mean vertical augmentation was 3.2 mm, reduced to 2.1 mm (p < 0.01) after healing. The amounts of lateral and vertical graft resorption were similar (1.2 mm vs. 1.1 mm) but were different when compared with the original graft (22% vs. 34%). 49 implants were placed 4 months after grafting. Implant parameters were evaluated after 32–48 months follow up and demonstrated 100% survival rates. The use of mandibular bone grafts for 3D augmentation of the posterior maxilla has shown good results and minor complications.     

Brånemark and ITI dental implants in the human bone-grafted maxilla: a comparative evaluation

Abstract: The development of new characteristics concerning implant surface makes it interesting to clinically compare different implant systems in the bone‐grafted maxilla. The aim of this evaluation was to compare clinical data of a two‐staged procedure on the augmented extremely atrophic maxilla using either Brånemark‐ or ITI‐fixures. In 25 patients (18 females, seven males) the severely atrophied maxilla was reconstructed with autogenous iliac or mandibular bone and either Brånemark or ITI implants. Seventy‐eight Brånemark implants and 80 SLA‐ITI implants were inserted in the augmented bone and the patients were followed between 20 and 67 months post implantation. The bone graft was transplanted to add bony volume in the maxillary sinus, the anterior floor of the nose and/or the alveolar ridge. After a healing period of 4½ months, dental implants were inserted and left for healing for 8 months. Twelve consecutive patients received machine‐surfaced Brånemark fixtures and 13 consecutive patients received SLA‐ITI fixtures. Gradual loading was applied after healing abutment application. After 6 months the permanent prosthetic reconstruction was provided to the patient, either as a fixed or removable bridge. Comparison in survival rate was performed: 15 machined Brånemark fixtures were lost, resulting in an overall survival rate of 81%. Two ITI fixtures were lost, resulting in an overall survival rate of 98%. The results of this evaluation show that sandblasted large grit acid etched surface‐treated ITI implants has a significant higher survival rate than machine‐surfaced Brånemark implants in autogenous grafted maxillary bone.     

Systematic review of short- (5–10 years) and long-term (10 years or more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants

Objectives

The aim of this systematic review was to investigate the short-term (5–10 year mean follow-up) and long-term (10 year or more) survival and success of fixed full arch dental hybrid prosthesis and supporting dental implants.

Methods

Studies reporting interventions with full-arch fixed dental hybrid prostheses were identified by searching PubMed/Medline (NCBI), Web of Science (Thomson Reuters), the Cochrane Register of Controlled Clinical Trials (EBSCO), and Dentistry and Oral Sciences Source (DOSS; EBSCO) from the earliest available dates through July 17, 2013. Through a series of review process by two examiners, potentially qualifying studies were identified and assessed with respect to the inclusion criteria.

Results

A total of 18 studies were included for the quality assessment and the systematic review. Within the limitation of available studies, high short-term survival rates of full arch fixed dental hybrid prostheses (93.3–100%) and supporting implants (87.89–100%) were found. However, the availability of studies investigating long-term outcomes seemed scarce. Furthermore, the included studies were subjected to potential sources of bias (i.e. publication, reporting, attrition bias).

Conclusions

Despite seemingly high short-term survival, long-term survival of implant supported full arch fixed dental hybrid prosthesis could not be determined due to limited availability of true long-term studies. Although it may be a valuable option for a patient with a completely edentulous ridge(s), the strategic removal of teeth with satisfactory prognosis for the sake of delivering an implant supported full-arch dental hybrid prosthesis should be avoided.     

Which prosthetic treatment concepts present a reliable evidence-based option for the edentulous maxilla related to number and position of dental implants?

Purpose: The objective of this systematic review, serving as a basis for an expert consensus conference, was to answer the following questions: Which prosthetic treatment concept related to implant number and position presents a reliable evidence-based option for the edentulous maxilla? How many implants should be installed and what kind of implant prosthesis works most efficiently related to this number? Previously, these questions could not be answered adequately, although several meta-analyses considering the respective issues have been published. However, some reports included study designs with a low level of evidence (e.g. retrospective) and observation periods of less than 3 years. In this systematic review, stricter inclusion criteria were used in an attempt to reach a higher level of evidence. Materials and methods: An electronic MEDLINE (PubMed) search was conducted to identify all relevant studies concerning either fixed or removable implant prosthetics. The most important inclusion criteria were: the trial had to be an randomised controlled trial (RCT) or at least prospective (minimum observation period of 3 years); endosseous implants were examined; details on implant and/ or prosthesis survival were provided. Results: The search revealed 988 abstracts of possible relevance. Twenty-nine publications met the inclusion criteria. In total, 7028 implants and 1130 patients were observed. Because of the heterogeneity among the included studies, a statistical analysis of the extracted data was questionable. Conclusions: Owing to different study protocols (with different implant systems, loading protocols, surgical procedures, designs of supraconstructions, etc.), varying statistical methods, and often missing information of the included studies, highly reliable conclusions are hardly possible. Welldesigned RCTs are needed to provide scientifically validated prosthetic treatment protocols.     

A three-year follow-up report of a comparative study of ITI Dental Implants and Brånemark System implants in the treatment of the partially edentulous maxilla

Background: Many longitudinal studies of different implant systems have been published but few controlled randomized investigations have been reported. A 1‐year report of a comparative study of ITI Dental Implant System® implants (Straumann AG, Waldenburg, Switzerland) and Brånemark System® implants (Nobel Biocare AB, Gothenburg, Sweden) has been published by the present authors. This paper is a 3‐year follow‐up of that randomized study. Purpose: The aim of the study was to compare the outcome of fixed partial prostheses supported by ITI or Branemark implants. The outcome was evaluated primarily in terms of survival rates and changes in marginal bone level. Material and Methods: The study group comprised 28 patients with anterior residual dentition in the maxilla. The patients were provided with two to four implants on each side of the dentition and were randomly allocated to Brånemark implants or ITI implants; 77 ITI implants and 73 Brånemark implants were inserted. After 6 months abutment connections were made to both ITI and Brånemark implants. All patients were provided with fked partial prostheses of gold‐ceramic. The patients were followed up annually with clinical and radiographic examinations for 3 years. Results: Two Brånemark implants and two ITI implants were lost. The Brånemark implants were lost before loading whereas the ITI implants were lost because of periimplantitis. The survival rate for both groups was 97.3%. The mean marginal bone level of the Brånemark implants was situated 1.8 mm from the reference point at both the baseline and the 3‐year examinations. The corresponding values for the ITI implants were 1.4 mm at baseline and 1.3 mm after 3 years. There was no significant difference between the implant systems with regard to bone level or bone level change. A steady state of the marginal bone level was calculated to have been reached after 3 years for 95.5% of the Brånemark implants and 87.1% of the ITI implants. Periimplantitis (infection including pus and bone loss) was observed with seven ITI implants but with none of the Brånemark implants. This difference was statistically significant. Conclusions: No statistically significant differences were found between the implants studied, except for the frequency of periimplantitis, which was higher for the ITI implants. The survival rates were high, and the marginal bone loss was small for both systems.     

Full-mouth rehabilitation of an edentulous patient with Papillon-Lefèvre syndrome using dental implants: a clinical report

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder. The oral manifestations of the syndrome include rapidly progressive periodontal disease resulting in premature exfoliation of primary and permanent dentitions. Patients are often edentulous at an early age and require prosthodontic treatment. This report is the oral rehabilitation of an edentulous 21-year-old woman with PLS. Treatment included maxillary and mandibular fixed prostheses supported by osseointegrated dental implants. At the 4-year follow-up, the patient presented significant improvements in oral function and psychosocial activities and no prosthetic complications.     

Cervical metastases of squamous cell carcinoma of the maxilla: a retrospective study of 25 years

Objectives

Squamous cell carcinomas (SCCs) of the maxilla are relatively rare; therefore, only little data is available regarding the frequency of cervical metastasis (CM) and therapy strategies. Most authors only undertake clinical observation of the lymph nodes. The aim of this retrospective study was to evaluate the manner of metastasis in SCC of the maxilla.

Materials and methods

All patient records from 1987 to 2011 were scanned for SCC of the maxilla. Patients with SCC limited to the maxilla were comprised. The cases were analyzed regarding tumor node metastasis staging system and any special occurrences in the follow-up time such as tumor recurrence, metastasis, and exitus letalis. Classification and staging were performed according to the 2003 UICC system.

Results

One hundred thirty-eight patients were comprised of 36 % females and 64 % males (average age, 66 years; women, 71 years; men, 63 years). The average follow-up time was 43 months (range, 0–195). Fifty-eight percent smoked or declared regular consumption of alcohol. About 50 % of the patients had an advanced tumor stage (III–IV). At the time of the primary diagnosis, 38 % of the patients had CM. There is an increased risk for CM occurrence with increasing tumor size and grading and a tumor localized in the postcanine region. Contralateral CM arises frequently in T4 tumors and tumors localized in the postcanine region.

Conclusion

The data exhibit aggressive regional metastatic behavior of SCC of the maxilla.

Clinical relevance

Therefore, surgical treatment of the draining lymphatic system as a primary management strategy is recommended for patients with SCC of the maxilla.     

Immediate functional loading of Brånemark system implants in edentulous mandibles: clinical report of the results of developmental and simplified protocols

PURPOSE: This report evaluates the 5-year results of 9 of 10 patients in a clinical investigation of immediate functional loading of Br?nemark System implants in edentulous mandibles, and of 24 patients treated with a simplified protocol for the same indication. The purpose of the paper is to suggest a simple, reliable, and documented method for immediate implant loading of complete-arch mandibular prostheses. MATERIALS AND METHODS: Ten healthy patients in need of full-arch mandibular implant reconstruction (development group) were treated between December 1993 and December 1994 with 130 Br?nemark System standard Implants, placed in fresh extraction and healed sites. Four implants per patient were immediately loaded with acrylic resin fixed prostheses. The prostheses were replaced by metal-framework conversion prostheses approximately 6 weeks later, and definitive metal-reinforced prostheses incorporating all implants were placed after second-stage surgery. An additional 24 patients were treated with a simplified protocol using a total of 144 implants placed between March 1997 and October 2000. In these patients, the acrylic resin prostheses were not disturbed for 3 months, and fewer implants were used with an increasing ratio of implants loaded. Eventually, all Implants were loaded immediately for the last patients treated. RESULTS: The prosthesis survival rate was 100% for the total material. In the developmental group, the implant cumulative survival rate was 80% for the immediately loaded implants after 5 years, while the 2-stage implants reached 96%. Bone level measurements showed no differences between immediate and 2-stage protocols for this group. The implant cumulative survival rate was 97% for the simplified treatment group. DISCUSSION AND CONCLUSION: A predictable and simple concept for loading of immediate implant prostheses in edentulous mandibles was demonstrated. Results from the development of this technique suggest that it may be essential to maintain the initial implant splinting over a healing period of about 3 months and that implant placement between the mental foramina provides optimal support.     

How has the dental literature evolved over time? Analyzing 20 years of journal self-citation rates and impact factors

Abstract

Objective: As journal impact factors (IFs) can be artificially inflated by excessive journal self-citation practices, research quality evaluation based solely on IF ranking may be manipulated and, therefore, ethically challenged. This study aimed to analyze the longitudinal development of journal self-citation rates (SCRs) and IFs in dental literature and to determine possible confounders.

Methods: Twenty-eight journals with scope within general dentistry and (sub)specialties listed in 1997–2016 Journal of Citation Reports^® were scrutinized. The following information was retrieved: publication year, total number of citations, number of self-citations, IF, corrected IF, and SCR.

Results: Endodontic journals had the highest SCR (median = 35.3, IQR = 21.6–47.5), journals related to periodontics had the lowest (median = 14.7, IQR = 8.9–25.5). Periodontics had the highest IF (median = 2.1, IQR= 1.7–2.8) and general dentistry had the lowest (median = 0.9, IQR = 0.7–1.2). SCR significantly decreased over time (p?<?.0001) by 1 unit per year. Additionally, 1 unit increase in corrected IF resulted in 15.2 units decrease in SCR. IFs significantly increased 0.06 units per year (p?<?.000).

Conclusions: Overall, favourable changes in citation metrics have been observed for dental journals during the 20-year observation period. SCR significantly decreased per observation year whereas IFs significantly increased, indicating a healthy publishing environment in the dental literature. SCR was regulated both by time and corrected IF.     

Clinical evaluation of direct pulp capping using a calcium silicate cement—treatment outcomes over an average period of 2.3 years

Objectives

This study aims to assess the treatment outcomes of direct pulp capping with a calcium silicate cement (Biodentine) after caries excavation.

Materials and methods

A total of 245 teeth of 226 patients diagnosed to be clinical healthy or showing spontaneous pain were directly capped. The teeth were examined 0.19 to 7.4 (mean 2.3 ± 2.04) years after treatment. The following data were recorded: age and sex of the patient, type of tooth and restoration (glass ionomer cement [GIC], amalgam, composite resin, ceramic, gold) and symptoms before or after treatment. The evaluation of the treatment was carried out by sensibility and percussion testing and by the patient’s questioning. A positive sensibility test, a negative percussion test, the absence of swelling and discomfort were considered as treatment success. Survival analysis was performed using the Kaplan-Meier, log-rank, Chi-square and Fisher’s exact test, respectively.

Results

After an average period of 2.3 years, 86.0% of the teeth remained vital; the survival rate after 7.4 years was 83.4%. The treatment outcome was significantly worse for cavities restored with GIC compared to all other restorative materials (p < 0.05). All other evaluated factors had no significant influence on the success rate (p > 0.05).

Conclusion

Exposed pulps of asymptomatic vital permanent teeth and teeth with spontaneous pain before treatment can be successfully capped directly using Biodentine. A subsequent restoration with GIC does not appear to be suitable as it significantly reduces the success of the treatment.

Clinical relevance

Direct pulp capping can be done successfully with this type of calcium silicate cement.

     

Early functional loading of conical Brånemark implants in the edentulous mandible: a 12-month follow-up clinical report

Treatment of patients with implant-supported mandibular fixed prostheses performed according to an early loading concept has shown excellent results in several reports. The outcome of such treatments with 4 implants, in which the posteriors are distally inclined, has not been reported. This clinical report describes a 12-month evaluation of 17 consecutive patients with 68 conical Br?nemark implants placed between the mental foramina according to a 1-stage surgical procedure. Fixed mandibular prostheses were connected to the implants an average of 33 days after implant placement. Clinical and radiographic examinations were performed at the time of placement of the fixed prosthesis and at a 12-month examination. Five implants were lost during the observation period, 3 before loading and 2 after prosthesis connection, rendering an implant survival rate of 93%. One patient lost her prosthesis because of a failing implant. The average marginal bone loss was 0.24 mm.