Could Future Implant Failures be Predicted Based on Observed Bone Levels and Bone Loss After 5 Years? A Retrospective Investigation on Patients Presented in Previous Studies.

Purpose: To evaluate the diagnostic accuracy of bone loss/bone levels, as detected after 5 years of implant function, in identifying patients who suffered implant failures in the following 5 years. Materials and Methods: Data on radiographic measurements of marginal bone levels at prosthesis placement and after 5 years of function were retrospectively retrieved from 11 previous publications. Included patients were allocated into different subgroups with regard to bone loss/bone level during/after 5 years in function, respectively. A diagnostic test was used to estimate the accuracy of finding patients/jaws/implants at risk for a future implant failure by calculating sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) in different subgroups, respectively. Results: Altogether, 749 treated jaws (723 patients/3,363 implants) were included in the study group. Treated jaws in the high-level subgroups presented an overall higher risk of implant failures from 5 to 10 years in function (P < .05). Many treated jaws/implants were allocated into the high-level groups, but the proportions of implant failures were low in these groups. The diagnostic test comparing high- and low-level groups with and without implant failures showed low accuracy to predict implant failures; the PPV ranged from 4% to 33%. Lower PPVs were observed for diagnostic tests for individual implants (range: 4% to 6%). Conclusion: More severe bone loss was associated with higher risk of future implant failure. However, many patients/ implants with obvious bone loss in the study group and low prevalence of implant failures at the 10-year examination resulted in poor accuracy in identifying individual patients or implants at risk for failure. This suggests that it is difficult to predict future implant failures based only on radiographic measurements.

Could Age at Surgery Be Associated with Early Mortality After Implant Surgery? A Retrospective Study of 3,877 Edentulous Patients.

PURPOSE: Knowledge of the early mortality patterns in edentulous implant patients is limited. This study aimed to report patient mortality within the first year after surgery and compare the cause of death with preexisting conditions reported before surgery. MATERIALS AND METHODS: In this retrospective cohort study, data from the Swedish National Death Register on patients, consecutively treated in the edentulous arch between 1986 and 2013, were compared with information from the patient files regarding the preexisting health conditions of the deceased patients. One-year survival rates were calculated and compared with expected mortality in a Swedish reference population based on three age groups: young (< 45 years of age), middle-aged (45 to 64 years of age), and old patients (> 64 years of age). Proportions of mortality between study groups and reference populations were tested by means of a log-rank test, and agreement between diagnoses before surgery and cause of death was tested by means of kappa test. RESULTS: Altogether, 3,877 patients were included, of whom 60 patients died within 1 year after implant surgery (1.5%). The expected mortality in the Swedish reference population was 2.1% (P < .05). Mortality was higher for middle-aged (P = .02) but lower for old patients (P = .0001) compared with the Swedish reference populations. Eight of the deceased patients (13%) had no preexisting conditions, while 48 patients reported a health diagnosis before implant surgery. The most common of these were related to the circulatory system (ICD 10-I), which was the cause of death for 30 patients. A "none to slight agreement" between presurgical diagnoses and cause of death was observed in the population (kappa: 0.152). CONCLUSION: Edentulous implant patients presented overall lower mortality than expected in the general population during the first year after surgery. However, middle-aged patients showed a higher proportion of deceased patients compared with control people of the same age. Cardiovascular diseases were the cause of death in 50% of the group, and the agreement between presurgical and cause of death diagnoses was poor.

Bone Loss Before and After Peri-implantitis Surgery: A 7-Year Retrospective Observational Study.

PURPOSE: This study aimed to report changes in implant bone levels before and after peri-implantitis surgery (P-IS). MATERIALS AND METHODS: Patients were treated with P-IS from 2003 to 2010 and thereafter followed up until the last available radiographic examination (study termination: October 2018). Bone loss was measured before and after P-IS, and the numbers of clinical examinations post-P-IS were determined. The Student t test was used to compare the bone loss between examinations and reference populations, and correlations between different variables were calculated using the Pearson correlation coefficient (r). RESULTS: One hundred thirty-four consecutive patients (137 arches) underwent P-IS during the inclusion period (2.3%). A total of 122 patients (125 arches) were followed up for a mean period of 6.9 (SD: 5.54) and 7.3 (SD: 3.39) years from the first annual examination to before P-IS, and from the time of P-IS to after P-IS, respectively. The mean bone loss during the aforementioned durations was 0.18 (SD: 0.23) and 0.26 (SD: 0.28) mm/year, respectively (P < .05). Bone loss per year was also greater for unaffected implants after (0.29 [0.34] mm/year) compared with before P-IS (0.06 [0.10] mm/year; P < .05). No difference in bone loss was observed between peri-implantitis affected and unaffected implants or between implants with a turned or moderately rough surface after P-IS. A greater amount of bone loss was associated with increasing numbers of clinical examinations and shorter follow-up times after P-IS (P < .05). CONCLUSION: Average bone levels decreased from the time of prosthesis placement to termination of the study. Bone loss increased after P-IS in the total and unaffected group, and edentulous patients compared unfavorably with partially and single implant conditions. Increased bone loss was associated with higher numbers of clinical examinations per year of followup after P-IS (P < .05).

Mortality in Edentulous Patients: A Registry-Based Cohort Study in Sweden Comparing 8463 Patients Treated with Removable Dentures or Implant-Supported Dental Prostheses.

OBJECTIVES: The purpose of this study was to investigate if edentulism is associated with all-cause mortality. The aims were to analyze the association between age, socioeconomic factors, and mortality in edentulous patients treated with either removable dentures or implant-supported prostheses. METHODS: All patients who became edentulous according to the Swedish Social Insurance Agency (SSIA) between 2009 and 2013 (N = 8463) were analyzed regarding prosthetic treatment, age, gender, and socioeconomic status. The patients were divided into two groups, depending on whether they were treated with dental implants (implant group; IG) or with conventional removable dentures (denture group; DG). Data on mortality for all included individuals were obtained from the Swedish National Cause of Death Register and compared to a reference population. Cumulative survival rates were calculated, and a multivariable regression analysis for the included variables was performed. RESULTS: Between 2009 and 2018, 2192 of the patients (25.9%) were treated with implant-supported dental prostheses (IG) and 6271 patients (74.1%) were treated with removable dentures without support of dental implants (DG). Altogether 2526 patients (30%) died until December 31, 2019, and the overall mortality was significantly higher for the DG compared to the IG during follow-up (p < 0.001). Younger edentulous patients (≤59 years) presented a higher mortality than the reference population, while implant patients over 79 years of age demonstrated a lower mortality. The final results from the multivariable logistic analysis showed that lower equalized disposable income (EDI) and the choice of conventional removable dentures are the most important factors for increased patient mortality (p < 0.001). CONCLUSIONS: Edentulous patients have an overall higher mortality compared to a reference population. Low socioeconomic status increases all-cause mortality. Individuals treated with dental implants show statistically significant lower 10-year mortality compared to patients treated with conventional removable dentures, regardless of socioeconomic status.

3-D tooth movement adjacent to single anterior implants and esthetic outcome. A 14- to 20-year follow-up study.

OBJECTIVES: To report three-dimensional (3-D) movement of teeth adjacent to single-implant crowns (SICs) in the anterior maxilla and to relate the findings to patient characteristics and esthetic outcome. MATERIALS AND METHODS: 3-D movements of teeth adjacent to anterior maxillary SICs were measured in 30 patients with original SICs in function after 14-20 years. The movements were related to facial type, lower anterior facial height (LAFH), age at crown delivery, sex, the position of the implant, implant occlusion, cause of tooth loss, follow-up period, orthodontic treatment prior to implant placement, and marginal bone-level changes. The esthetic outcome and quality were assessed using Visual Analog scale (VAS) and California Dental Association (CDA) index. RESULTS: 3-D movement of adjacent teeth between 0 and 2.5 mm was observed at follow-up with incisal and palatal movement being most pronounced. Incisal tooth movement of >1 mm was observed in 30% of the patients and was significantly associated with LAFH ≥70 mm. VAS rating associated poorly between patients and clinicians with scores of >80% in 63% and 20%, respectively. The CDA rating was assessed as satisfactory in 87% of the patients. CONCLUSIONS: Significantly more extensive infraposition was observed in patients with SICs without occlusion, other causes of tooth loss than trauma, implant in lateral incisor and canine position, and a LAFH of ≥70 mm. Although infraposition occurs, patients are highly satisfied with the esthetics of their implants and the esthetic results are valued as higher by patients than dentists.

Patient factors related to early implant failures in the edentulous jaw: A large retrospective case-control study.

BACKGROUND: Dental implants provide anchorage for dental prostheses to restore functions for individuals with edentulous jaws. During the healing phase, proper osseointegration is required to prevent early implant failure. More knowledge is needed regarding factors related to early failure of dental implants. PURPOSE: The aim of the present study was to identify possible risk factors for early implant failure, with respect to anamnestic and clinical parameters. MATERIALS AND METHODS: All patients with edentulous jaws with early implant failure (n = 408) from one referral clinic were compared with a matched control group (n = 408) with no implant failure. Early implant failure was identified during the first year of prosthetic function. Matching was performed on age, gender, year of surgery, type of jaw, and type of implant surface. In addition, data on anamnestic and clinical parameters were collected. The data were analyzed with a multivariable logistic regression model using early implant failure as the binary outcome. RESULTS: Five anamnestic factors were statistically significant with respect to higher probability for early implant failure: systemic disease, allergies in general, food allergies, smoking, and intake of analgesic medication. Four clinical conditions (i.e., implants in the opposing jaw, low primary stability, reduced bone volume, and healing complications) were also related to higher probability for early implant failure. CONCLUSIONS: This study identified nine factors associated with early implant failure, several related to patient's general health. Further investigations are needed to fully understand the causality between the obtained variables and early implant failure.

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.

Are marginal bone level changes around dental implants due to infection?

BACKGROUND: Peri-implant bone level values have been used as the clinical standard of reference to describe the status of a dental implant. Reduction of marginal bone levels in association with bleeding on probing have been claimed to be a sign of pathology and an indication of treatment needs. PURPOSE: To assess the available evidence that peri-implant bone loss is caused by infection. MATERIALS AND METHODS: This article is a narrative review on the interpretation of marginal bone level changes around dental implants as a consequence of infection. RESULTS AND CONCLUSIONS: There is evidence that plaque accumulation induces an inflammatory reaction in the peri-implant soft tissues and that resumption of plaque control measures results in the reduction of the inflammation. Since plaque is always present in the oral cavity, a cause-effect relationship between plaque accumulation and peri-implantitis, defined as inflammation of the peri-implant soft tissues associated with marginal bone loss has been difficult to validate and has not been proven so far. There is no evidence of the mechanisms involved in the tissue reactions resulting in the conversion from a state of an inevitable inflammation contained in the soft tissues to a state of inflammation involving the loss of peri-implant marginal bone. There is today no consensus whether implants should be expected to be surrounded by tissues which are completely free from inflammation, or that an "immune-driven", chronic, subclinical inflammation should be expected at the foreign body implant. The infectious origin theory appears to be mainly supported by ligature-induced experimental peri-implantitis investigations in animal models that suffer of several methodological problems, and therefore, provide misleading information with regards to human clinical applications in large, routine populations.

Implant failures before and after peri-implantitis surgery: A retrospective study on 207 consecutively treated patients.

PURPOSE: This study aimed to report implant failures before and after peri-implantitis surgery (P-IS) and to compare the pattern of implant failures with in untreated at-risk patients during the same period. MATERIALS AND METHODS: A total of 5628 untreated at-risk patients (7240 jaws) and 207 consecutively patients treated with P-IS (212 jaws) were included in two groups. Implants were placed and followed-up between 1986 and 2018. Cumulative survival rates (CSR) for patients treated with P-IS after 2003 were calculated before and after P-IS and compared with those for nontreated patients. RESULTS: The overall 15-year CSR was 91.2% (CI 95%; 90.5%-91.9%) and 68.5%, (CI 95%, 62.1%-75.5%) for untreated patients at risk and P-IS patients, respectively (P < .05). The 10-year CSR (baseline 1 year after implant surgery) was 97.2% (CI 95%, 95.2%-100%) for treated patients before P-IS which was comparable with that for untreated patients: 95.4% (CI 95%, 94.8%-97.7%). The corresponding 10-year CSR for P-IS patients after surgery was significantly lower (71.6%: CI 95%, 63.1%-81.3% (P < .05)). CONCLUSION: CSR for patients/jaws without implant failures was comparable between untreated and treated P-IS patients before, but lower for P-IS patients after P-IS (P < .05). A negative effect of P-IS on implant survival after treatment cannot be disregarded.

Implant failures and age at the time of surgery: A retrospective study on implant treatment in 2915 partially edentulous jaws.

PURPOSE: To further report and analyze data on the prevalence of implant failures related to age at surgery in partially edentulous jaws. MATERIALS AND METHODS: Altogether, 2915 partially edentulous jaws (Kennedy Class I and II) were consecutively treated with 9167 implants over a 30-year period (1986-2015) in one referral clinic. All implant failures were consecutively recorded and the first event of implant failure was analyzed in relation to patient age at implant surgery. RESULTS: A total of 2453 patients participated in the study. The main observations were a nonlinear, normal distribution association between risk of implant failure and age at surgery with the highest risk in middle-aged patients. The risk for implant failures was significantly higher for middle-aged patients (45-64 years) than for old patients at the time of surgery (P < .05). The overall cumulative survival rates for treated jaws increased consistently from the age group of 40 to 49 years to that of >79 years. However, younger age groups (<40 years) presented a different pattern. Partially edentulous patients included late in the study (2003-2015) presented a more pronounced nonlinear, normal distribution, and the highest risk of implant failure in patients between 50 and 55 years of age at surgery. CONCLUSIONS: An overall nonlinear risk pattern of implant failure was observed, with the highest risk in the middle-aged group at implant surgery. Overall cumulative survival rates were highest in the youngest and oldest age groups at implant surgery, and this pattern became more pronounced in patients included late in the study.

Bone loss around oral and orthopedic implants: An immunologically based condition.

BACKGROUND: Marginal bone resorption has by some been identified as a "disease" whereas in reality it generally represents a condition. PURPOSE: The present article is a comparison between oral and orthopedic implants, as previously preferred comparisons between oral implants and teeth seem meaningless. MATERIALS AND METHODS: The article is a narrative review on reasons for marginal bone loss. RESULTS AND CONCLUSIONS: The pathology of an oral implant is as little related to a tooth as is pathology of a hip arthroplasty to a normally functioning, pristine hip joint. Oral as well as orthopedic implants are recognized as foreign bodies by the immune system and bone is formed, either in contact or distance osteogenesis, to shield off the foreign materials from remaining tissues. A mild immune reaction coupled to a chronic state of inflammation around the implant serve to protect implants from bacterial attacks. Having said this, an overreaction of the immune system may lead to clinical problems. Marginal bone loss around oral and orthopedic implants is generally not dependent on disease, but represents an immunologically driven rejection mechanism that, if continuous, will threaten implant survival. The immune system may be activated by various combined patient and clinical factors or, if rarely, by microbes. However, the great majority of cases with marginal bone loss represents a temporary immune overreaction only and will not lead to implant failure due to various defense mechanisms.

Causes of Death in Implant Patients Treated in the Edentulous Jaw: A Comparison between 2098 Deceased Patients and the Swedish National Cause of Death Register.

BACKGROUND: Previous research has reported an association between tooth loss and patient mortality, while the cause of death has not been elucidated. OBJECTIVE: The purpose was to describe and compare the cause of death in implant patients treated consecutively in the edentulous arch with a reference population. METHODS: Altogether, 3902 patients were included between 1986 and 2014. Data on the causes of death for deceased patients were compared to the Swedish National Cause of Death Register for a comparable time period. Standardised mortality ratios (SMRs) were calculated based on gender and age and tested for statistical significance. RESULTS: Most deceased patients (2,098) died from diseases in the circulatory system (CVD; 42%) and from cancers (26%). SMR indicated a generally increased mortality (total group) compared to the reference population during inclusion (P < 0.05; 1986-2014). Patients treated early (1986-1996) showed a lower SMR compared to patients treated later (P < 0.05; 1997-2014) especially related to CVDs. Younger patients (<60 years at surgery) showed an increased mortality due to CVDs when treated late (1997-2014; SMR = 5.4, P < 0.05). Elderly patients (>79 years at surgery) showed a significantly lower mortality in almost all observed causes of death (1986-2014; P < 0.05) with also a significantly lower mortality due to CVDs during the early period (1986-1996; SMR = 0.3, P < 0.05). CONCLUSION: An overall increased mortality was observed for the edentulous implant patient compared to the reference population. Elderly patients (>79 years) showed significantly lower mortality for all causes of death independent of the time period of implant surgery. Younger patients (<60 years) present an increased risk for early mortality related to CVD. SMR for all causes of death increased for patients treated late (1997-2014) as compared to patients treated early (1986-1996).

Implant Survival in the Posterior Partially Edentulous Arch-30 Years of Experience. Part IV: A Retro-Prospective Multivariable Regression Analysis on Implant Failures Related to Arch and Implant Surface.

PURPOSE: To report implant failures in partially edentulous patients over a long-term period, focusing on differences in treatment outcomes between maxillary vs mandibular arches and different implant surfaces. MATERIALS AND METHODS: Altogether, 2,453 patients were consecutively treated with 9,167 implants in 2,915 partially edentulous arches (Kennedy Class I or II) between 1986 and 2015 at one referral clinic. Implant failures were recorded on a routine basis at the clinic during follow-up, and the failures were analyzed with a focus on associations with treated arch and implant surface by means of a multivariable regression analysis. RESULTS: Cumulative survival rates (CSRs) for arches provided with turned surface implants were 92.2%, 90.6%, 89.7%, and 88.3% after 5, 10, 15, and 25 years, respectively. Corresponding CSRs for arches provided with moderately rough surface implants were 95.7% and 95.2% after 5 and 10 years, respectively. Two individual surgeons and prosthetic treatment outside the referral clinic showed strong associations with early implant failure (P < .05). Implants with a turned surface showed an increased risk for failure early after surgery (< 1 year), but a comparable pattern of a reduced risk by time was present during the late period of follow-up (> 1 year) for both surface types. Variables associated with the number of implants per operation were associated with increased risk of implant failure for both implant surface types (P < .05). CONCLUSION: Individual surgeons seem to have an important impact on early risk of implant failure in combination with implant surface, number of placed implants, wide-platform implants, and treatment in the mandible. Observed differences in survival between different implant surfaces seem to be established early after surgery, but the risk during the following long-term period is reduced by time, and risk seems to be comparable for both surface types in both the maxilla and the mandible during maintenance.

Implant failures and age at the time of surgery: A retrospective study on implant treatments in 4585 edentulous jaws.

BACKGROUND: There is limited knowledge on the relationship between implant failures and patient age at implant surgery. PURPOSE: To further analyze and report long-term data on previously presented significant associations between implant failures and age at surgery in patients receiving treatment in the edentulous jaw. MATERIALS AND METHODS: A total of 4049 patients were provided with 24 781 implants during 4585 operations in edentulous jaws between 1986 and 2015 in one referral clinic. Patients were thereafter invited to be followed up until the termination of the study. All implant failures were recorded, and nonlinear spline statistical methods and calculations of survival curves for different age groups were used to analyze implant failures related to age at surgery. RESULTS: Ten-year age groups presented consistently higher overall survival rates with increasing age. The overall 10-year survival rates for treated jaws without failures ranged between 83.4% and 91.0% for different age groups. The risk of implant failures in 50-year-old patients was higher than in older patients within 15 years of follow-up (66/78 years; P < 0.05). The difference between young (<45 years), middle-aged (45-64 years), and old (>64 years) patients became more pronounced in patients included later in the study (2003-2015). CONCLUSIONS: Young edentulous patients presented an overall significantly higher risk of implant failure than did old patients. The risk decreased consistently from patients in the youngest age group (30-39 years) to those in the oldest age group (>79 years), with a more pronounced pattern for the patients included in the late period. This finding suggests a change in patient characteristics during the time of inclusion, but no causal explanations for the present observations have been established.

Implant Survival in the Partially Edentulous Jaw- 30 Years of Experience. Part III: A Retro-Prospective Multivariate Regression Analysis on Overall Implant Failures in 2,915 Consecutively Treated Arches.

PURPOSE: To report implant failure rates in a large group of partially edentulous patients over a long-term period and to analyze possible associations between available clinical variables and implant failure. MATERIALS AND METHODS: Altogether, 2,453 patients were consecutively provided with 9,167 implants in 2,915 partially edentulous arches (Kennedy Class I or Class II) between 1986 and 2015 at one referral clinic. All implant failures recorded at the clinic during follow-up were identified and analyzed in relation to available clinical variables by means of a multivariable regression analysis. RESULTS: Overall cumulative survival rates (CSRs) for treated arches without any implant failures after 15 and 25 years were 91.7% and 90.3%, respectively, and the corresponding CSRs for implants were 96.1% and 95.3%, respectively. Out of the 209 arches with reported implant failures, 112 were reported with failures during the first year (54%). The strongest associations with risk for overall implant failure were related to two different surgeons (hazard ratio 6.14 [2.77 to 13.60] and 1.51 [1.14-1.99]). Number of implants, time since surgery, calendar year of surgery, and age at surgery were also significantly associated with overall implant failure. Furthermore, early implant failures were associated with implant surface (HR 2.27 [1.43 to 3.57]), indicating higher risk for implants with a turned surface. This variable was not observed for overall or late implant failures. CONCLUSION: Individual surgeons seem to have an important impact on risk for implant failure in combination with implant surface and number of placed implants during the early period after surgery. Besides the surgeon and number of implants, the overall trend seems to be a decreasing risk for failure the longer the patient is followed up, the later the patient is included, and the older the patient is at treatment.

Rehabilitation of Edentulism and Mortality: A Systematic Review.

PURPOSE: It has been shown that tooth loss is associated with an increased risk of early mortality, and that prosthetic rehabilitation of edentulism improves quality of life and reduces morbidity. This review examines association between prosthetic rehabilitation of the edentulous state with a complete denture and mortality. METHODS: A systematic search using combinations of related keywords for "complete denture" and "mortality" was performed on PubMed, Web of Science, and Google Scholar. A reference search of included articles and author contacts was also performed. RESULTS: None of the studies reported results for association between mortality and wearing complete dentures among edentulous individuals; however, based on the published methods and results, a total of 15 studies were found to be eligible for author contacts to obtain relevant data. Overall, 5 eligible studies were included and critically evaluated to summarize their findings. The follow-up period in these studies ranged from 3 to 24 years, and the age group of included samples ranging from 52 to 105 years. The proportion of individuals not wearing dentures ranged from 3.0% to 13.3%. Four of the included studies showed fewer individuals without complete dentures surviving over the follow-up years as compared to the group wearing complete dentures. One of two studies that could adjust for certain confounders found no significant difference in mortality after adjusting, but another study found a 42% reduced risk of dying among those wearing complete dentures, as compared to those not wearing complete dentures after adjusting for age, sex, educational level, smoking, alcohol drinking, body mass index, time spent walking daily, medical history, psychological distress score, energy intake, and protein intake. Due to the small sample size of nondenture wearers, it was not possible to analyze with statistical rigor the comparative risk of dying associated with wearing or not wearing complete dentures. CONCLUSION: Most of the included studies indicated a higher proportion of deceased edentulous patients not using dentures as compared to denture wearers. Nevertheless, small sample size prevents a definite conclusion being drawn regarding a relationship between prosthetic rehabilitation and mortality among edentulous individuals.

On inflammation-immunological balance theory-A critical apprehension of disease concepts around implants: Mucositis and marginal bone loss may represent normal conditions and not necessarily a state of disease.

BACKGROUND: Oral implants have displayed clinical survival results at the 95%-99% level for over 10 years of follow up. Nevertheless, some clinical researchers see implant disease as a most common phenomenon. Oral implants are regarded to display disease in the form of mucositis or peri-implantitis. One purpose of the present article is to investigate whether a state of disease is necessarily occurring when implants display soft tissue inflammation or partially lose their bony attachment. Another purpose of this article is to analyze the mode of defense for implants that are placed in a bacteria rich environment and to analyze when an obtained steady state between tissue and the foreign materials is disturbed. MATERIALS AND METHODS: The present article is authored as a narrative review contribution. RESULTS: Evidence is presented that further documents the fact that implants are but foreign bodies that elicit a foreign body response when placed in bone tissue. The foreign body response is characterized by a bony demarcation of implants in combination with a chronic inflammation in soft tissues. Oral implants survive in the bacteria-rich environments where they are placed due to a dual defense system in form of chronic inflammation coupled to immunological cellular actions. Clear evidence is presented that questions the automatic diagnostics of an oral implant disease based on the finding of so called mucositis that in many instances represents but a normal tissue response to foreign body implants instead of disease. Furthermore, neither is marginal bone loss around implants necessarily indicative of a disease; the challenge to the implant represented by bone resorption may be successfully counteracted by local defense mechanisms and a new tissue-implant steady state may evolve. Similar reactions including chronic inflammation occur in the interface of orthopedic implants that display similarly good long-term results as do oral implants, if mainly evaluated based on revision surgery in orthopedic cases. The most common mode of failure of orthopedic implants is aseptic loosening which has been found coupled to a reactivation of the inflammatory- immune system. CONCLUSIONS: Implants survive in the body due to balanced defense reactions in form of chronic inflammation and activation of the innate immune system. Ten year results of oral and hip /knee implants are hence in the 90+ percentage region. Clinical problems may occur with bone resorption that in most cases is successfully counterbalanced by the defense/healing systems. However, in certain instances implant failure will ensue characterized by bacterial attacks and/or by reactivation of the immune system that now will act to remove the foreign bodies from the tissues.

Implant Survival in the Edentulous Jaw: 30 Years of Experience. Part II: A Retro-Prospective Multivariate Regression Analysis Related to Treated Arch and Implant Surface Roughness.

PURPOSE: To report retro-prospective, long-term data on the prevalence of implant failures related to maxillary and mandibular arches and to different implant surfaces in a large number of edentulous patients. MATERIALS AND METHODS: Altogether, 3,493 and 1,092 edentulous arches were consecutively treated with implants with turned (1986-2002) or moderately rough (2003-2015) surfaces, respectively, during two time periods at one referral clinic. All implant failures were consecutively identified during routine follow-up, and a multivariate logistic regression analysis was performed to analyze implant failure related to arch and implant surface. RESULTS: Overall cumulative survival rates (CSR) for arches treated with turned surface implants were 75.7% and 94.6% for the maxilla and mandible, respectively. The corresponding 10-year CSRs for arches treated with implants with a moderately rough surface were 91.9% and 96.1%, respectively. The strongest significant association (P < .05) with risk for implant failure was the maxilla, and this was more pronounced for implants with a turned surface. Age at surgery, implant surgeon, calendar year of surgery, and time of follow-up also had significant associations with risk of implant failure (P < .05). CONCLUSION: Risk for implant failure was significantly higher for treatment in the maxilla, but this risk was decreased significantly when using implants with a moderately rough surface. The impact of surface was not so obvious for treatment in the mandible. Risk for late implant failures after the first year was lower for implants with a moderately rough surface in the maxilla, but this risk seemed to be comparable for the different surfaces in the mandible.

Early Implant Failures in Edentulous Patients: A Multivariable Regression Analysis of 4615 Consecutively Treated Jaws. A Retrospective Study.

PURPOSE: To study the incidence of early implant failures in edentulous jaws and to describe the effects of some patient- and implant-related factors on the risk for early implant failures. MATERIALS AND METHODS: The study retrospectively analyzed 4615 edentulous jaws (4067 patients), consecutively treated with dental implants at one referral clinic from 1986 to 2013. Implant failures that occurred from implant surgery up to the first recall examination 1 year after prosthesis insertion were recorded and defined as early implant failures. All removed implants were included as failures. Features of the study group and early implant failure rates were reported. A multivariable logistic regression model was used for analyzing possible associations between clinical factors, and the risk for early implant failures. Implant surfaces were categorized by means of roughness: turned (Sa 0.5-1.0 µm) and moderately rough (Sa 1.0-2.0 µm). RESULTS: Three hundred twenty-seven patients (344 jaws) were lost to follow-up. Early implant failures occurred in 8.6% of the jaws. In the maxilla there was a significantly higher incidence of early failures compared to the mandible both with turned implants, OR 5.93 (95% CI 4.21; 8.36), and moderately rough implants, OR 2.52 (95% CI 1.19; 5.34). The impact of implant surface roughness was significant in the maxilla with higher incidence of early failures with turned implants, OR 3.51 (95% CI 2.27; 5.42). There was a significant interaction between implant surface and jaw type on early failures (p = 0.034). Older age was associated with lower risk for early implant failures, OR 0.9 (95%CI 0.82; 0.99). In total, 63% of the jaws with failure could proceed with the prosthetic treatment without further implant insertions. Twenty-six percent of the early failures occurred after prosthesis insertion and 59% of those could maintain the same prosthesis after implant loss with or without adjustments. CONCLUSIONS: Changing the implant surface from turned to moderately rough decreased the incidence of early implant failures significantly in the maxilla, but not in the mandible. Older age at implant insertion was associated with lower risk for early implant failures in edentulous patients.