Factors affecting soft tissue around dental implants: a review of the literature

Much of the focus in the early dental implant literature is on the bone-to-titanium interface because a successful osseointegrated implant requires direct bone contact to the implant surface. The research on soft tissue around dental implants has focused on the partially edentulous patient and, in particular, on the maxillary anterior dentition. Few studies have evaluated soft tissue around dental implants in completely edentulous patients over time. This paper reviews the pertinent literature on soft-tissue healing in both partially and completely edentulous dental implant patients from a Medline search of the English peer-reviewed literature from 1980 to 2004.     

Analysis of incidence and associated factors with fractured implants: a retrospective study

Osseointegrated threaded titanium screw-type implants rarely lose integration after the first year of clinical function. Implant failure can occur for other reasons, with implant fracture being one of the major reasons for late failure. The purpose of the present study was to determine the incidence of implant fracture in completely edentulous and partially edentulous arches and to determine what factors may predispose an implant to a higher fracture risk. A retrospective evaluation of 4,937 implants was performed to determine the incidence of and factors common to fractured implants from a sample of implants placed and restored in one institutional setting. Based on the results of this study, the following observations were made: implants fracture at similar rates in the maxilla as in the mandible (0.6%), implant fractures occur more frequently in partially edentulous restorations (1.5%) than in restorations of completely edentulous arches (0.2%), all observed fractures occurred with commercially pure 3.75-mm-diameter threaded implants, and prosthetic or abutment screw loosening preceded implant fracture for the majority of the implants. More studies would be helpful to further explore the relationship and progression of factors associated with implant fracture.     

Retrospective analysis of 56 edentulous dental arches restored with 344 single-stage implants using an immediate loading fixed provisional protocol: statistical predictors of implant failure

PURPOSE: The purpose of this retrospective study was to evaluate the effects of implant dimensions, surface treatment, location in the dental arch, numbers of supporting implant abutments, surgical technique, and generally recognized risk factors on the survival of a series of single-stage Straumann dental implants placed into edentulous arches using an immediate loading protocol. MATERIALS AND METHODS: Each patient received between 4 and 18 implants in one or both dental arches. Periapical radiographs were obtained over a 2- to 10-year follow-up period to evaluate crestal bone loss following insertion of the definitive metal-ceramic fixed prostheses. Univariate tests for failure rates as a function of age (< or = 59 years versus > or = 60 years), gender, smoking, bone grafting, dental arch, surface type, anterior versus posterior, number of implants per arch, and surgical technique were made using Fisher exact tests. The Cochran-Armitage test for trend was used to evaluate the presence of a linear trend in failure rates regarding implant length and implant diameter. Logistic regression modeling was used to determine which, if any, of the aforementioned factors would predict patient and implant failure. A significance criterion of P = .05 was utilized. RESULTS: Data were collected for 344 single-stage implants placed into 56 edentulous arches (39 maxillae and 17 mandibles) of 43 patients and immediately loaded with a 1-piece provisional fixed prosthesis. A total of 16 implants failed to successfully integrate, for a survival rate of 95.3%. Increased rates of failure were associated with reduced implant length, placement in the posterior region of the jaw, increased implant diameter, and surface treatment. Implant length emerged as the sole significant predictor of implant failure. CONCLUSION: In this retrospective analysis of 56 consecutively treated edentulous arches with multiple single-stage dental implants loaded immediately, reduced implant length was the sole significant predictor of failure.     

Conversion of a complete denture to a provisional implant-supported,screw-retained fixed prosthesis for immediate loading of a completely edentulous arch

This article describes the fabrication of a provisional implant-supported, screw-retained restoration for immediate loading of a completely edentulous arch. The technique can be applied to patients with partially edentulous arches as well. Until immediate loading of dental implants becomes a well-documented treatment modality, the described method should not be applied on a routine basis or without careful evaluation.     

Placement and restoration of dental implants in a patient with Paget's disease in remission: literature review and clinical report.

Paget's disease is a disorder of bone that results in the replacement of normal bone with highly vascularized, low density bone. The diminished bone quality associated with Paget's disease is a relative contraindication to the use of dental implants, as it interferes with achievement of osseointegration. There is no current literature on the success of dental implants in patients with Paget's disease. Furthermore, there is no current literature on dental implant success in patients with remissive Paget's disease or in bone that appears to be unaffected by the disease in patients with Paget's. This case report follows the treatment of a patient with a partially edentulous maxilla and mandible (ACP PDI Classification III) who presented with remissive Paget's disease. Definitive treatment included the placement of four endosseous implants used to retain full veneer crowns. Despite the radiographic appearance of adequate bone quality, upon surgical placement it was discovered that the quality of bone was poor, yet implant survival was achieved through careful surgical management and rigid splinting of some of the endosseous implants.     

"All-on-Four" immediate function concept and clinical report of treatment of an edentulous mandible with a fixed complete denture and milled titanium framework.

The "All-on-Four" concept-tilting the distal implants in the edentulous arches improves the prosthetic support-increases the inter-implant distance and provides better implant anchorage in the bone by using longer implants. Computer milling of a solid block of titanium also provides frameworks with improved fit and fewer technical challenges than conventional cast or noncast approaches. This clinical report describes a method of restoring an edentulous mandible with the "All-on-Four" immediate function concept and a milled titanium framework. The patient in our clinical report has reported for follow-up visits for 1 year and is satisfied with the outcome of the treatment. No discernable clinical and radiographic changes were noted around the dental implants. To date, there have been no prosthetic complications. The patient is scheduled for quarterly follow-ups to determine the effectiveness of home care.     

Use of mini implants for replacement and immediate loading of 2 single-tooth restorations: a clinical case report

Numerous long-term studies have shown that treatment with dental implants can provide edentulous patients with a more stable alternative to complete dentures and partially edentulous patients with a more conservative form of tooth replacement than conventional fixed partial dentures. Until recently, commercially available dental implants have been limited to diameters ranging from 3.0 mm to 7.0 mm. Although this range of diameters has been able to address most clinical needs, partially edentulous patients who could not accommodate a 3.0-mm-diameter implant without damaging adjacent dental structures were excluded from implant therapy. This article reports on the surgical treatment and immediate restoration of a patient who received mini implants that were 2.4 mm in diameter.     

Immediate loading of 190 endosseous dental implants: a prospective observational study of 40 patient treatments with up to 2-year data

PURPOSE: The present study was undertaken to determine the feasibility of using primary stability as a predictor of implant success in patients whose implants were immediately loaded. MATERIALS AND METHODS: The study included 40 patients, in whom a total of 190 implants were placed, 102 in maxillary sites and 88 in mandibular sites. All were loaded within 72 hours of placement. Sixteen patients were completely edentulous in the mandible and/or the maxilla. The remaining 24, who were partially edentulous, received fixed partial dentures or single-implant restorations. All of the definitive implant restorations were screw retained. The criterion for loading was clinical judgment of primary stability, verified by a "screw test." Impressions were made after implant placement to facilitate the fabrication of a laboratory-made heat-processed provisional restoration from acrylic resin. Following a 4-month period for osseointegration and soft tissue healing, definitive fixed prostheses were fabricated. RESULTS: There were no surgical complications. After 1 to 2 years, all 190 implants had survived and were considered 100% successful, as determined by independent testing of mobility and radiographic evidence of osseointegration. In 4 patients, fracture of the provisional restoration occurred during the healing period. DISCUSSION: Clinical research has shown that immediate loading is a viable treatment modality. The favorable success rate reported in this study for rough-surfaced implants suggests that adherence to a protocol, an important parameter of which is primary stability above 32 Ncm, can lead to osseointegration. CONCLUSION: The results of this limited investigation suggest that patients who are partially or completely edentulous may be immediately restored with implants and fixed provisional restorations, provided that the dental implants are adequately stable immediately after their surgical placement. This alternative therapeutic approach did not appear to affect the up-to-2-year survival of the implants in this patient population.     

Outcome of treatment with implant-retained dental prostheses in patients with Sj?gren syndrome.

The purpose of this investigation was to evaluate the outcome of treatment with implant-retained prostheses in patients suffering from Sj?gren syndrome. Eight women were included in the study; all had suffered oral symptoms of Sj?gren syndrome for many years. Seven patients were edentulous in both arches, and 1 patient was edentulous in the maxilla only. All patients reported poor or very poor comfort levels with their conventional dentures. It was the intention to treat each arch that showed subjective and objective denture problems with a complete fixed prosthesis after placement of 6 implants. In all, 54 Br?nemark dental implants were placed in these patients. No implants were lost, but 7 implants in 4 patients were clinically not osseointegrated at the time of the abutment connection procedure. Because of nonosseointegrated implants and lack of jawbone, 3 arches were treated with an implant-retained overdenture. Fixed prostheses were made with a titanium framework of premachined components welded together (Procera) and acrylic resin teeth and flanges. Patients answered a questionnaire regarding their oral function before the onset of treatment and 1 month and 2 years after treatment. An average radiographic bone loss of 0.7 mm from the time of implant placement to 1 year after treatment was observed; additional bone loss of less than 0.6 mm was recorded 4 years after treatment. During the first year of function 2 implants lost osseointegration. No prostheses were lost or remade. Treatment with implant-retained prostheses considerably increased the prosthetic comfort and function of the patients. Two years after prosthetic treatment, only 1 patient indicated poor comfort of the prostheses, while the remaining patients reported good or very good comfort levels.     

Immediate placement of bone level Sraumann implants: a case series

Endosseous dental implants have revolutionized the methods clinicians use to treat edentulous and partially edentulous patients. Traditional implant protocol specifies a healing period of several months after tooth extraction, as well as an unloaded healing period prior to restoration. Over the last decade, numerous studies have documented successful immediate placement of endosseous dental implants in fresh extraction sites and have found positive results with early functional loading. The purpose of this article is to present a clinical treatment protocol for the immediate placement and early loading of dental implants and to report the clinical and radiographic outcomes of the SLActive surface Straumann Bone Level implant placed in either maxillary or mandibular fresh extraction sockets.     

An assessment of crown-to-root ratios with short sintered porous-surfaced implants supporting prostheses in partially edentulous patients

PURPOSE: Implant length, implant surface area, and crown-to-root (c/r) ratio and their relationship to crestal bone levels were analyzed in 2 groups of partially edentulous patients treated with sintered porous-surfaced dental implants. MATERIALS AND METHODS: One hundred ninety-nine implants were used to restore 74 partially edentulous patients with fixed prostheses. Implants were categorized according to their length ("short" versus "long") and estimated surface area ("small" versus "large"). "Short" implants had lengths of 5 or 7 mm, while "long" implants were either 9 or 12 mm in length. "Small" implants had estimated surface areas of < or = 600 mm2, while "large" implants had estimated surface areas > 600 mm2. Other data collected included c/r ratio (measured on articulated diagnostic casts), whether or not the implants were splinted, and standardized sequential radiographs. RESULTS: The mean c/r ratio was 1.5 (SD = 0.4; range 0.8 to 3.0), with 78.9% of the implants having a c/r ratio between 1.1 and 2.0. Neither c/r ratio nor estimated implant surface area (small or large) affected steady-state crestal bone levels. However, implant length and whether the implants were splinted did appear to affect bone levels. Long implants had greater crestal bone loss (0.2 mm more) than short implants; splinted implants showed greater crestal bone loss (0.2 mm more) than nonsplinted ones. These differences were statistically significant. DISCUSSION AND CONCLUSIONS: Sintered porous-surfaced implants performed well in short lengths (7 mm or less) in this series of partially edentulous patients. The data suggested that long implants and/or splinting can result in greater crestal bone loss; longer implants and splinted implants appeared to favor greater crestal bone loss in this investigation. These conclusions are, of course, specific to the implants used and would not be relevant to other implant types.     

Removable partial denture design involving teeth and implants as an alternative to unsuccessful fixed implant therapy: a case report

Various dental implants have been used, and high success rates have been reported. However, as their uses increase, implant failures have been reported. There are partially edentulous patients with an initial treatment plan of an implant-supported fixed partial denture. At times, one or more strategic implants fail to osseointegrate. In situations where financial, systemic, or local conditions preclude the use of a fixed partial denture, a well constructed removable partial denture can be an excellent treatment alternative. It has been reported that prosthesis support can be improved with the use of osseointegrated dental implants, with improved preservation and maintenance of existing hard and soft tissues around dental implants. This article describes the prosthodontic rehabilitation of a partially edentulous patient by the use of a removable partial denture design involving teeth and implants as an alternative to unsuccessful fixed implant therapy. This treatment option solved a difficult clinical problem derived from the failure of two strategic implants and provided the patient with an esthetic and functional prosthesis.     

自体胫骨骨松质移植提升上颌窦与骨内牙种植

本文通过8例自体胫骨骨松质移植提升上颌窦的成功．认为上颌窦底自体胫骨骨松质移植对于解决上颌后区牙槽嵴萎缩、上颌窭与牙槽嵴接近而又需要进行骨内种植牙的病人提供了一种良好的方法。胫骨近中外上髁作为供骨区有明显的优点，可以获得质量高、数量较多的骨质．骨面与皮肤接近．创口小，并发症少。     

A multicenter report on 1,022 consecutively placed ITI implants: a 7-year longitudinal study

The aim of this multicenter study was to evaluate cumulative success and survival rates of ITI implants after 7 years. A complete medical report was obtained for all 440 patients enrolled in this investigation, which involved 10 different private practices. The 1,022 consecutively placed implants were distributed between completely edentulous, partially edentulous, and single-tooth replacement cases. During the annual follow-up visit, each implant was examined both clinically and radiographically using predefined success criteria. The cumulative survival and success rates were calculated for all implants. Implant subgroups were defined according to the medical history of the patients or pooled according to various indications, locations, implant designs, or implant lengths. In each subgroup, the related cumulative success rate was statistically compared to the global cumulative success rate. Fifteen implants (1.4%) were regarded as early failures, and at the end of the follow-up, the global failure rate reached 6.6%; 30 implants (3%) were lost to follow-up. At 5 years, the cumulative survival rate was 95.4%; this declined to 92.2% at 7 years. The weakest success rates were observed for implants placed in older patients, periodontally treated patients, and completely edentulous arches. Conversely, cumulative success rates that were significantly above average were observed for patients between 40 and 60 years old without pathology, implants placed after bone regeneration, solid-screw implants, implants placed in edentulous spaces, and implants placed as single-tooth replacements. This investigation has demonstrated that in these 10 private practice settings, the success rate for ITI implants remained high for up to 5 years and declined slightly between 5 and 7 years. It should be noted that in later year intervals, a relatively small number of implants remained for the analysis of cumulative success rates.     

无抗生素预防感染的牙种植治疗效果

目的：探讨无抗生素预防的牙种植效果，为临床提供理论依据。方法：将牙种植患者154名随机分为两组，对照组83名（196枚种植体）给予口服青霉素V（PC－V）预防处理，实验组71名（167枚种植种）术前、术后均不给予抗生素治疗。结果：经统计学分析，两组之间术后感染率无显著性差异，上颌骨与下颌骨种植体的存留率也无显著性差异。结论：在常规牙种植外科应用抗生素预防感染是无意义的。     

Spline implant prospective multicenter study: interim report on prosthetic screw stability in partially edentulous patients

Loosening of implant abutment and prosthesis screws during functional loading is an industrywide phenomenon that is especially well documented with the external hexagon implant connection. Although numerous efforts to reduce or eliminate screw loosening have been attempted, the problem still persists, especially with implant restorations in the partially edentulous patient. In 1992, the spline was developed as an alternative to the external hexagon implant-abutment connection. A prospective multicenter study was begun in 1996 to evaluate the abutment and prosthesis screw joint stability of Spline® dental implants (Centerpulse Dental Division, Carlsbad, California) over 5 years of post-loading clinical follow-up. From October 1996 to December 2000, 73 partially edentulous patients were consecutively treated with 113 Spline implants placed in two private dental practices. Three patients with 1 implant each withdrew from the study for various reasons; of the remaining 110 implants in 70 patients who continued in the study, 82% (n = 90) were placed between 1997 and 1998. No cases of abutment or prosthesis screw loosening occurred with up to 54 months (mean = 38.95 mo; range, 3–54 mo; mode, 20 mo) of post-loading clinical follow-up. These interim findings of the ongoing study suggest that Spline dental implants may provide a stable prosthetic connection in partially edentulous cases during short-term clinical follow-up.
CLINICAL SIGNIFICANCE
If left untreated, implant-related screw loosening can potentially lead to bone loss, component breakage, and even implant failure. The results of this study suggest that the Spline implant may provide predictable screw joint stability in partially edentulous cases.     

Basic surgical principles with ITI implants

The basic surgical principles governing the placement of ITI implants are based on research-oriented developments in harmony with evidence-based and outcome-oriented clinical procedures. In the past 15 years, the range of implant indications has been significantly widened, and partially edentulous patients clearly represent the majority of patients seeking treatment with dental implants today. An important aspect of the successful rehabilitation of patients with ITI implants is the careful selection of implant candidates with respect to systemic and local risk factors. These factors are presented based on current knowledge. Today, solid-screw implants in various screw dimensions and neck configurations comprise the ITI Dental Implant System. These different implant types are necessary to handle the full range of implant indications, in particular in partially edentulous patients. The main clinical factors are presented for the selection of the appropriate implant type, length and diameter. These implants are utilized both in a non-submerged and in a submerged approach. The main goal of surgical therapy is low trauma and the least demanding surgical procedure for patient and clinician to optimize the cost-effectiveness of implant therapy. Hence, a non-submerged approach is preferred in all sites without esthetic priority, such as in fully edentulous patients or in posterior sites of partially edentulous patients. These indications clearly represent the majority of implant patients. In esthetic sites, a submerged approach is utilized to satisfy the specific esthetic demands. The possibility to successfully utilize short implants (6 and 8 mm) and a reduced healing period of 3 months are further advantages of ITI implants due to favorable properties of the rough TPS surface. With the introduction of the microrough SLA surface, a reduction of the healing period to 6 weeks facilitates further progress towards simplification of implant therapy. In summary, the ITI Dental Implant System represents a scientifically well-documented, complete implant system for the treatment of fully and partially edentulous patients, offering straightforward surgical concepts based on predictable treatment outcome and excellent cost-effectiveness.     

Flapless implant surgery: a 10-year clinical retrospective analysis

PURPOSE: This article is a retrospective clinical analysis of implants placed with a flapless approach. MATERIALS AND METHODS: Seven hundred seventy implants were placed in 359 patients to restore both completely edentulous and partially edentulous arches with fixed prostheses or removable complete dentures. Each patient was examined after 3 months, 6 months, 1 year, and then once every year. Prostheses were removed, if possible, and implant mobility was assessed, periapical radiographs were obtained, and periodontal probing was performed. Implants were considered failed if they had mobility or pain, had to be removed, or if they showed more than 0.5 mm of bone loss per year and signs of active peri-implantitis. RESULTS: The cumulative success rate for implants placed using a flapless 1-stage surgical technique after a 10-year period varied from 74.1% for implants placed in 1990 to 100% at 2000. DISCUSSION: Since flapless implant placement is a generally "blind" surgical technique, care must be taken when placing implants. Angulation of the implants affected by drilling is critical to avoid perforation of the cortical plates, both lingual or buccal, especially on the lingual in the mandibular molar area and the anterior maxilla. There should be no problem if the patient has been appropriately selected and an appropriate width of bone is available for implant placement. There is a learning curve to every surgical procedure, after which it becomes routine. There are many advantages for the patient as well as for the surgeon, since the procedure is less time consuming, bleeding is minimal, implant placement is expedited, and there is no need to place and remove sutures. CONCLUSION: Flapless implant surgery is a predictable procedure if patient selection and surgical technique are appropriate.     

Crestal Bone Changes at Teeth and Implants in Periodontally Healthy and Periodontally Compromised Patients. A 10‐Year Comparative Case‐Series Study

Background: Limited data exist on the longitudinal crestal bone changes around teeth compared with implants in partially edentulous patients. This study sought to compare the 10‐year radiographic crestal bone changes (bone level [BL]) around teeth and implants in periodontally compromised (PCPs) and periodontally healthy (PHPs) patients. Methods: A total of 120 patients were evaluated for the radiographic crestal BL around dental implants and adjacent teeth at time of implant crown insertion and at the 10‐year follow‐up. Sixty patients had a previous history of periodontitis (PCPs), and the remaining 60 were PHPs. In each category (PCP and PHP), two different implant systems were used. The mean BL change at the implant and at the adjacent tooth at the interproximal area was calculated by subtracting the radiographic crestal BL at the time of crown cementation from the radiographic crestal BL at the 10‐year follow‐up. Results: At 10 years after therapy, the survival rate ranged from 80% to 95% for subgroups for implants, whereas it was 100% for the adjacent teeth. In all eight different patient categories evaluated, teeth demonstrated a significantly more stable radiographic BL compared with adjacent dental implants (teeth BL, 0.44 ± 0.23 mm; implant BL, 2.28 ± 0.72 mm; P <0.05). Radiographic BL changes around teeth seemed not to be influenced by the presence or absence of advanced bone loss (≥3 mm) at the adjacent implants. Conclusions: Natural teeth yielded better long‐term results with respect to survival rate and marginal BL changes compared with dental implants. Moreover, these findings also extend to teeth with an initial reduced periodontal attachment level, provided adequate periodontal treatment and maintenance are performed. As a consequence, the decision of tooth extraction attributable to periodontal reasons in favor of a dental implant should be carefully considered in partially edentulous patients.     

A 48-month multicentric clinical investigation: implant design and survival

This report is based on a total of 2,955 implants of 6 different designs, randomized and placed in 829 patients and followed for 48 months. Implant failure was defined as nonintegration at uncovering or removal due to mobility, persistent pain, infection, and evidence of radiographic bone loss. Failures were reported for 3 phases of treatment: implant placement to uncovering (phase 1), uncovering to loading (phase 2), and postloading (phase 3). Differences in survival were compared with Kaplan-Meier survival curves. The maxillary single tooth application resulted in 95.2% survival for the hydroxyapatite-coated grooved implants. In the maxillary completely edentulous application, survival of hydroxyapatite grooved and screw implants were considerably better compared with the titanium screw implants. The hydroxyapatite-coated cylinder had better survival than the titanium basket and screw designs in the mandibular completely edentulous application. The hydroxyapatite-coated cylinder and grooved implants in the maxillary posterior partially edentulous application had similar survival rates. The survival of the hydroxyapatite-coated cylinder exceeded that of the titanium basket in mandibular posterior partially edentulous applications. Analyses by phase of treatment indicated a pattern of early failure for nonhydroxyapatite-coated implants compared with hydroxyapatite-coated implants. The implant with the highest survival at all phases of treatment was the hydroxyapatite-coated press-fit cylinder. Two hydroxyapatite-coated implant designs performed well in the challenging posterior maxillary region.