Immediate Implant Placement with Different Interradicular Osteotomies in the Mandible: A Randomized Clinical Study.

AIM: To assess the implant stability and amount of marginal bone loss in immediate implant placement (IIP) in mandibular molars by using pre-extractive interradicular implant bed preparation vs conventional post-extractive interradicular implant bed preparation. MATERIALS AND METHODS: This randomized clinical trial was conducted on fourteen patients who had an immediate dental implant at the mandibular molar area by two different techniques. All patients were divided randomly into two equal groups: Group I (control) was treated with conventional post-extractive interradicular implant bed preparation, and group II (test) was treated by pre-extractive interradicular implant bed preparation All surgeries were performed by the same surgeon. All patients were followed up clinically at immediate post-surgery (T0), 7 days (T1), 3 weeks (T2), 90 days (T3), and 3 months after loading (T6) for healing and to evaluate the marginal bone loss radiographically at T0, T3 and T6. Descriptive and bivariate statistics were computed using the SPSS version (SPSS, IBM Inc., Chicago, IL), and p ≤ 0.05 was considered an indicator of statistical significance. RESULTS: A total of 7 female and 7 male patients with a mean age of 32.07 ± 5.87 years. Radiographically, there is no significant statistical difference in comparing between two groups for the marginal bone loss. However, there was a highly significant statistical difference (p < 0.001) in each group between different interval periods (T0, T3, T6) with mean start 5.27 ± 0.53, and 5.19 ± 0.72 at (T0) reaching 7.60 ± 0.89 and 7.09 ± 0.96 at (T3) and slightly decrease of 7.52 ± 0.79 and 7.02 ± 0.79 in (T6) with radiographic evaluation, and it represented clinically in each group with mean 3.57 ± 0.313 and 4.0 ± 0.58 at (T0) increase to 6.55 ± 0.395 and 6.52 ± 0.45 at (T6) for both group respectively. There is no statistically significant difference in soft tissue healing with an average mean of 4.57 ± 0.24 and 3.57 ± 0.509 (p = 0.001) when comparing between both groups respectively. CONCLUSION: Both techniques seem useful for dental implant placement in badly decayed mandibular molars. However, pre-extracted interradicular implant bed preparation for IIP might offer advantages in terms of primary implant stability and bone preservation. However, further studies are needed to confirm these findings. CLINICAL SIGNIFICANCE: Both techniques are alternative methods for the treatment of badly decayed mandibular molars by immediate dental implant except for minor complications that do not interfere with dental implant placement. How to cite this article: Alzaibak LMA, Abdel-Monem TM, Elgohary NM, et al. Immediate Implant Placement with Different Interradicular Osteotomies in the Mandible: A Randomized Clinical Study. J Contemp Dent Pract 2024;25(4):303-312.

Evaluation of dentin features in teeth after caries removal by three techniques (chemomechanical, mechanical with a smart bur, and air-abrasion): an in vitro study.

Background: Different methods for removing dental carious lesions exist, including conventional rotary caries removal and new advanced technology like polymer-based burs, chemomechanical agents, air abrasion, and laser. Objectives: This study shows the differences in features of dentin (smear layer, patency of dentinal tubules, surface irregularities, intertubular micro porosities, and exposed dentinal tubules) among different types of caries removal techniques. Materials and Methods: An in vitro study was done on 60 primary molars with occlusal class I active caries. Teeth were divided into three groups according to a method of caries removal (G1: chemomechanical, G2: mechanical with a smart bur, and G3: air-abrasion). After complete caries excavation, the teeth were examined under a scanning electronic microscope (SEM) with the power of magnification 4,000x and 8,000x to show the morphological dentinal features with SEM microphotographs. Data obtained was analyzed using the SPSS program where Fisher exact, Kruskal-Wallis and multiple Wilcoxon sum rank tests were used. The level of significance is when the p-value is less than 0.05. Results: Generally, SEM showed the highest ratio of score 1 of smear layer presence, surface irregularities, and microporosity in all groups in both magnifications. The patency of tubules showed the highest ratio of score 1 in G1, scores 2 in both G2 and G3 in magnification 4,000x, while 8,000x there was the highest ratio of its score 1 in G1 and G2 while the G3 has score 2 as the highest score. The exposed dentinal tubules showed the highest ratio in G1 in score 3, in G2 in score 2, and in G3 in score 1 in magnification 4,000x, while 8,000x there was the highest ratio of its score 2 in both G1 and G3 while the G3 has highest score 1. The study with magnification 4,000x showed a significant difference (S) among three groups in exposed dentinal tubules with a p-value (0.012), and there was S between chemomechanical and smart, chemomechanical and air-abrasions groups with a p-value (0.041, 0.001 subsequentially). Other dentin features showed non-significant differences (NS) among or between groups in both magnifications (4,000x, 8,000x). Conclusions: All groups were effective in removing caries and can successfully treat young, scared or stressed patients. All methods of caries removal produce clinically parametric changes in the residual dentin.

Physiological occlusal force attenuates replacement root resorption of replanted teeth: an experimental animal study.

BACKGROUND: Tooth avulsion represents the most severe form of dental trauma, necessitating tooth replantation as the primary treatment. However, the risk of replacement root resorption (RRR) poses a significant threat to tooth retention following replantation. This study preliminarily aimed to investigate the effect of physiological occlusal force on RRR after the replantation of avulsed teeth and to explore the potential underlying mechanisms. METHODS: Thirty-six 4-week-old male Sprague-Dawley rats underwent extraction and immediate replantation of their left maxillary molars. The rats were randomly divided into two major groups: the occluded (n = 18) group, where the opposite mandibular teeth were preserved; non-occluded (n = 18) group, where the opposite mandibular teeth were extracted. Within each major group, there were three subgroups corresponding to 7 days, 14 days, and 2 months, resulting in a total of six subgroups, (n = 6 per subgroup). The right maxillary first molars served as the normal control. Various periodontal characteristics were assessed using haematoxylin-eosin (H&E), tartrate-resistant acid phosphatase (TRAP) staining, and micro-computed tomography (micro-CT). RESULTS: Histological staining revealed that under occlusal force, the early stage (day 7) after tooth replantation mainly manifested as root surface resorption, especially in the non-occluded group, which gradually diminished over time. Cementum and periodontal ligament (PDL) repair was observed on day 14. Micro-CT analysis indicated a significant decrease in PDL width in the non-occluded group two months after replantation, consistent with the histological findings, signifying severe RRR in the non-occluded group. CONCLUSIONS: This study provides preliminary evidence that physiological occlusal force may attenuate osteoclastogenesis during the early stage of tooth replantation, thereby reducing the occurrence of RRR and promoting periodontal healing.

The history of treatment planning the extraction of the first permanent molar in the UK.

This paper researches the history of treatment planning for extraction of the first permanent molars and the early influence of American orthodontists on dental practice in the UK. It also discusses the development of clinical guidelines for the enforced extraction of first permanent molars to the present day.

Treatment outcomes of pulpotomy versus pulpectomy in vital primary molars diagnosed with symptomatic irreversible pulpitis: protocol for a non-inferiority randomised controlled trial.

BACKGROUND: Pulpectomy continues to be the standard treatment recommendation for management of vital primary molars diagnosed with symptomatic irreversible pulpitis. The recent decade has seen a paradigm shift in the treatment concepts of how vital mature permanent molars diagnosed with irreversible pulpitis can be more conservatively managed using vital pulp therapy techniques like pulpotomy. However, despite emerging evidence indicating similarities between primary and permanent tooth pulp response to dental caries, there is limited research on whether pulpotomy can be similarly used as a definitive treatment modality for vital primary teeth with irreversible pulpitis. This randomised controlled trial (RCT) aims to compare the treatment effectiveness of pulpotomy versus pulpectomy in management of vital primary molars diagnosed with symptomatic irreversible pulpitis over a two-year period. METHODS/DESIGN: This clinical study is a parallel, two-armed, open label, non-inferiority RCT with a 1:1 allocation ratio between the experimental intervention arm (pulpotomy) and the active comparator arm (pulpectomy). Healthy cooperative children, between 4-9 years of age, who have painful primary molars with clinical symptoms typical of irreversible pulpitis will be recruited after obtaining informed consent from their parents/legal guardians. 50 vital primary molars clinically diagnosed with symptomatic irreversible pulpitis will be randomly distributed between the two treatment arms. The primary outcomes that will be assessed are clinical and radiographic success after six-months, one-year and two-years of the trial interventions. The influence of baseline pre-operative variables (age; gender; tooth type; site of caries; pre-operative furcal radiolucency; pre-operative pain intensity) and intra-operative factors (time taken to achieve haemostasis) on treatment outcomes will also be assessed. The secondary outcome evaluated will be the immediate (24 h and 7 d) post-operative pain relief afforded by the two treatment interventions. DISCUSSION: This trial seeks to provide evidence on whether pulpotomy treatment can be no worse than the standard pulpectomy treatment for the management of symptomatic irreversible pulpitis in vital primary molars. TRIAL REGISTRATION: ClinicalTrials.gov (NCT06183203). Registered on 30 January 2024.

Has children's oral health-related quality of life improved more following necrotic primary molars pulpectomy or extraction?

STUDY DESIGN: A randomised parallel controlled clinical trial was conducted between 2013 and 2015 at the University of Sao Paulo, Brazil, to assess the impact of pulpectomy or extraction on the oral health-related quality of life (OHRQoL) of children with pulp necrosis in primary molars. STUDY SELECTION: Children between the ages of 3 and 5 who were in good health but had extensive caries in at least one primary molar with signs of pulpal necrosis (also as seen radiographically, caries reaching the pulp with no signs of internal or external resorption) were considered for inclusion. Additionally, teeth with sufficient structure for rubber dam placement were also included. Children with any systemic, neurological, or other conditions that negatively impacted their growth were excluded. CLINICAL PROCEDURES AND SUCCESS CRITERIA: After computer-generated randomisation, 100 children were assigned randomly into two groups: 50 in the pulpectomy group and 50 in the dental extraction group. A paediatric dentist performed all procedures under local anaesthesia without sedation or general anaesthesia, and a rubber dam was used for pulpectomy with composite restoration in a single session. The OHRQoL scores were evaluated at baseline, 4, 8, and 12 months using the Brazilian version of the Early Childhood Oral Health Impact Scale (B-ECOHIS) via face-to-face interviews with parents conducted by a researcher trained in a single-blinded fashion. Additionally, the child's self-reported dental anxiety was measured using the Facial Image Scale (FIS), and dental pain was assessed using the Wong-Baker Faces Pain Scale (WBFPS) immediately after the treatment as secondary outcomes. RESULTS: The mean difference (SD) in the total B-ECOHIS score between baseline and after 12 months was 12.66 (6.79) for the pulpectomy group and 10.94 (9.28) for the extraction group, with effect sizes of 3.2 (95% CI: 2.42-4.20) and 1.4 (95% CI: 0.84-2.11), respectively. While both treatments significantly improved the children's OHRQoL after 12 months, the pulpectomy group showed greater long-term improvement compared to the extraction group, with mean differences (SD) of 4.86 (6.13) and effect sizes of 0.8 (0.46-1.13; p < 0.001). Moreover, children in the extraction group showed higher levels of anxiety compared with those in the pulpectomy group at 12-month follow-up (OR = 2.52; 95% CI = 1.30-4.89), and they reported 93% more odds of 'dental pain with high level' immediately after treatment than those in the pulpectomy group (OR = 1.93; 95% CI = 0.83-4.49). CONCLUSION: Children treated with pulpectomy in their necrotic primary molars were found to have better OHRQoL than those who had their primary molars extracted.

Isolated fracture of the coronoid process following a molar extraction: A rare case report.

Isolated coronoid process fractures are uncommon, and iatrogenic isolated fractures are extremely rare. This case describes a displaced fracture of an isolated coronoid process thought to be due to excessive force applied by a dentist that had been overlooked and left untreated for about a month. The patient was a woman in her late 50's and she had undergone a molar extraction. Her dentist had confused her symptoms of trismus, pain, and facial oedema with the complex tooth extraction procedure. Following a cone-beam computed tomography (CBCT) scan we showed that the mandibular coronoid process on her right side had suffered a longitudinal fracture, and the fractured fragment had rotated upwards and inwards. Following successful surgical elimination of the fragmented coronoid process, the patient received targeted physiotherapy sessions that yielded excellent results. At the five-month follow-up, the ability of the patient to open her mouth had improved enormously, and her facial appearance almost recovered to its original state.

Successful Healing of Periapical Pathology with Partial Pulpotomy in a Mature Permanent Molar: A Case Report.

BACKGROUND Vital pulp therapy approaches are preferred over non-surgical root canal treatment, giving the advantage of preserving the vitality of the dental pulp and thus maintaining its benefits. Such approaches can be performed in teeth having normal apical area; however, performing vital pulp therapy approaches in teeth associated with periapical pathology remains controversial. CASE REPORT We present a case of a mature mandibular right first permanent molar tooth in a medically fit 10-year-old female diagnosed as asymptomatic irreversible pulpitis with asymptomatic apical periodontitis with periapical radiolucency having a periapical index (PAI) score of 4. Partial pulpotomy was performed instead of non-surgical root canal treatment due to uncooperativeness of the patient. Biodentine was used as a pulp capping material. The tooth was restored with resin composite permanent restoration. Six months after the procedure, an intraoral periapical radiograph revealed normal bone features with complete periapical pathology healing and development of intact lamina dura around the mesial and distal roots. The tooth responded normal to electric pulp testing (EPT), cold, percussion, and palpation tests. CONCLUSIONS Periapical pathology involvement having large periapical radiolucency exhibiting PAI score 4 in inflamed dental pulp tooth diagnosed as irreversible pulpitis does not necessitate non-surgical root canal treatment. Partial pulpotomy should be considered as an alternative treatment to promote the return dental pulp and periapical tissue to a healthy condition. Considering a similar approach in older patients would be interesting to gain a more comprehensive understanding of its potential as a treatment method.

Post-endodontic pain in curved canals prepared with different rotary instrumentation techniques: A randomized controlled trial.

BACKGROUND: Curved root canals are associated with the highest number of procedural errors during endodontic instrumentation. Recently, numerous rotary instruments have been developed, with both manual and automated mechanisms, to facilitate endodontic treatment and manage the complications related to it. OBJECTIVES: The aim of the study was to assess post-endodontic pain after using the HyFlex® EDM OneFile (HEDM), WaveOne® Gold (WOG) and XP-endo® Shaper (XPS) systems in the preparation of curved canals in patients with asymptomatic irreversible pulpitis. MATERIAL AND METHODS: A total of 45 molars with curved canals and asymptomatic irreversible pulpitis were randomly divided into 3 equal groups based on the instrumentation used: HEDM (group A); WOG (group B); and XPS (group C). All teeth were prepared according to the manufacturers' instructions. Postendodontic pain was assessed using the visual analog scale (VAS) at 6, 12, 18, 24, 48, and 72 h after root canal instrumentation. The data was analyzed using the one-way analysis of variance (ANOVA) and the paired-samples t test with the Bonferroni correction, with a p-value of 0.05 set for statistical significance. RESULTS: The highest levels of post-endodontic pain were recorded at 6 h after treatment. Then, the values gradually decreased until the pain nearly vanished after 72 h. No statistically significant differences were observed in the VAS scores between groups A and B. At the same time, group C showed the lowest VAS scores at all follow-up time points. CONCLUSIONS: The use of the XPS system resulted in the lowest pain scores at all follow-ups. The HEDM and WOG groups showed no differences in the pain scores throughout the whole follow-up period.

Biometric analysis of furcation area of molar teeth and its relationship with instrumentation.

The anatomy of furcation favours the bacterial retention and makes periodontal debridement as well as oral hygiene procedures difficult. Teeth that have lost attachment to a level of the furcation are said to have a furcal invasion or furcation involved.Involvement of furcation in a multi-rooted tooth poses a very different type of clinical situation in terms of establishment of diagnosis, determination of prognosis and of course planning the treatment modality.The present study was carried out on 200 selected extracted human first and second permanent molar teeth based on a predefined criteria. Teeth with prosthetic crowns, fused or fractured roots, those not fully developed, grossly carious or heavily restored at the cementoenamel junction (CEJ) were excluded from the study. The morphology of the root trunk was recorded by measuring various dimensions of the root trunk,including furcal angle and root trunk volume was calculated by using a custom made special apparatus. The furcation areas were debrided with different types of curettes in the market in order to see how best the instrument could be maneuvered in the furcation area. The data so obtained was statistically analysed using SPSS version 22. The highest root trunk volume and the longest root trunk length were found to be in the maxillary second molar. 48.60% furcations didn't allow instrument engagementof furcation area with standard area specific curettes. The proposal of inclusion of root trunk length (mm) is suggested in addition to classification of FI to have assess prognosis and appropriate treatment for of the involved tooth.

A retrospective study on iRoot BP Plus full pulpotomy for primary molars with partial irreversible pulpitis.

OBJECTIVES: This study aimed to observe the outcomes of iRoot BP Plus full pulpotomy in primary molars with partial irreversible pulpitis retrospectively. METHODS: Collect 102 cases of primary molars with partial irreversible pulpitis undergoing iRoot BP Plus full pulpotomy from January 2019 to August 2023, with a follow-up period of 24-47 months. Based on the presence of irreversible pulpitis symptoms before surgery, the included cases will be divided into asymptomatic group (n=53) and symptomatic group (n=49). Observe the clinical and imaging success rates of both groups. RESULTS: Clinical success rates were 96.2% and 97.9% in asymptomatic and symptomatic groups, and radiographic success rates were 96.2% and 93.9% respectively. CONCLUSIONS: iRoot BP Plus full pulpotomy can be used for the treatment of primary molars with partial irreversible pulpitis under an enhanced pulpotomy protocol.

Comparative evaluation of volumetric changes between two pediatric rotary files (Kedo-S plus, Kedo-SG blue) and manual files (hand K-files) during canal preparation of primary mandibular molars: an in-vitro nano-CT analysis.

Pediatric endodontics has become popular due to advancements in cleaning, shaping and irrigation systems, resulting in faster and effective removal of infected pulp, saving time, and creating a pathogen-free environment. The patented rotary file system, Kedo-S, designed for primary teeth, introduced a single file generation for efficient pulp therapy. However, there are currently no studies assessing canal preparation in primary mandibular molars using nano-CT (computed Tomography). To evaluate the volumetric changes of two recently introduced pediatric rotary file systems in comparison with conventional hand file systems in primary mandibular molar using an ultra-high resolution nano-CT. This in-vitro study was performed in extracted primary mandibular molar based on certain inclusion and exclusion criteria. Samples were prepared and working length was determined before the pre-operative scan using a high resolution nano-CT device (SkyScan 2214, Bruker, Kontich, Belgium). A single well-experienced pediatric dentist prepared the canals using three file systems: Kedo-S plus, Kedo-SG blue and Hand K-files. A post-operative scan was performed similar to pre-operative scan. Image reconstruction was performed with NRecon software for 3D volumetric visualization and analysis of the root canals. Kedo-SG blue file systems had the highest mean difference in the canal volume (8.85%). Hand K-files had the least difference at (1.24%) of canal volume. Kedo-S plus file system had a mean canal volume difference (6.14%) which is closer to hand K-files. Rotary file systems resulted in a significant enlargement of canals compared to hand files.

Unexpected sequel to the application of silver fluoride followed by stannous fluoride to an open carious lesion in a primary molar: A case report.

OBJECTIVES: The use of silver fluoride followed by stannous fluoride was designed for the treatment of open carious lesions in primary molars in dental outreach programs. However, during the COVID-19 pandemic when aerosol-producing procedures were inadvisable, one dental location started using it as the first stage in a two-visit restorative procedure for carious primary molars. If the gap between the fluoride application and the restoration placement stages was around 3-5 weeks it was noticed that a black friable crust appeared on the caries surface. To investigate further a normally discarded crust from one patient was retrieved and sent for analysis. MATERIALS AND METHODS: Two techniques suitable for identification and preliminary analysis of material of unknown composition, scanning electron microscopy and energy dispersive spectroscopy (EDS) were used. The only preparation was that the specimen was dried and coated beforehand. RESULTS AND CONCLUSIONS: This preliminary examination showed two unexpected findings. The first was that the crust surface indicated a possible dentine derivation as it was covered with reasonably evenly spaced holes. In addition, the EDS spectrum showed it to be, at least, partially mineralized. The second unexpected finding was that the surface was coated with electron-dense particles. The size of the particles and the EDS spectrum pointed to the likelihood of the majority of them being nanosilver. These unexpected findings suggest a possible new direction for research.

Evaluation of Regenerative Efficacy of Amnion and Chorion Membrane in Treatment of Mandibular Molar Furcation Defects: A Clinico-radiographic Study.

AIM: Amnion and chorion membranes possess unique inherited biological properties that enhance wound healing and may accelerate periodontal regeneration. The present study aims to evaluate and compare the efficacy of amnion and chorion membranes in the treatment of furcation defects. MATERIALS AND METHODS: A total of 20 patients were selected and were randomly allocated to group I and group II with 10 subjects in each group. Amnion and chorion membranes are placental-derived membranes that accelerate regeneration by having natural growth factors with their antimicrobial and inflammation reduction properties. Group I was treated using bone grafting with decalcified freeze-dried bone allograft (DFDBA) and placement of amnion as a membrane for guided tissue regeneration (GTR) whereas group II was treated using bone grafting with DFDBA and placement of chorion as a membrane for GTR. The patients were followed for clinical and radiographic parameters and were evaluated between 3 and 6 months after surgery. RESULT: In intragroup comparison, a significant difference was evident in both the groups for all the clinical and radiographic parameters within the groups. (p = 0.01) This means both amnion and chorion membranes showed statistically significant regenerative efficacy. In intergroup comparison, the results show that all the clinical parameters and radiographic parameters show no significant difference between the groups. CONCLUSION: The amnion and chorion membranes had similar regenerative efficacy in combination with DFDBA in patients with buccal degree II furcation defects in mandibular molars. CLINICAL SIGNIFICANCE: The amnion and chorion membranes have shown significant improvement in clinical and radiographic parameters when used for the treatment of buccal degree II furcation defects in mandibular molars. How to cite this article: Mallapragda S, Gupta R, Gupta S, et al. Evaluation of Regenerative Efficacy of Amnion and Chorion Membrane in Treatment of Mandibular Molar Furcation Defects: A Clinico-radiographic Study. J Contemp Dent Pract 2024;25(2):160-167.

Effect of low-level laser therapy in wound healing of primary molar teeth extraction.

INTRODUCTION: Tooth extraction in children requires attention to wound healing and pain management, which are influenced by patient-related factors and behavioral guidance. AIM OF THE STUDY: The study aimed to evaluate the effect of LLLT on healing sockets in pediatric patients with bilateral primary molar teeth extraction and determine its impact on pain management. METHODS: 6-10 years of age, systemically healthy, and with atraumatic extraction indications of bilateral primary molar teeth were included in the study (n = 40). In the first session, randomly selected teeth were extracted under local anesthesia. In the control group, only clot formation in the socket was observed and photographed. The other group extractions were performed 2 weeks later. The low-level laser therapy (LLLT) group was treated with a 980 nm wavelength, in a continuous emission mode, 0.5 W power, 300 J of energy, 400 µm tip, 60 s diode laser and photographed. Nonepithelialized surface measurements were performed using ImageJ. Pain assessment was performed using the Wong-Baker Pain Scale. Statistical analyses were performed using SPSS software. RESULTS: There was a statistically significant difference between the groups in the Wong-Baker values in 3rd day (p < 0.05). In soft tissue healing on the 3rd and 7th day, the nonepithelialized surface of the laser socket was smaller than that of the control group, and the measurement results were found to be statistically significant (p < 0.05). CONCLUSION: Although LLLT was not found to be very effective in reducing postoperative discomfort after extraction of primary molars, it provided better wound healing in extraction sockets.

Micro-computed tomographic evaluation of the shaping ability of three nickel-titanium rotary systems in the middle mesial canal of mandibular first molars: an ex vivo study based on 3D printed tooth replicas.

BACKGROUND: The preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The purpose of this study was to evaluate the ex vivo shaping ability of 3 nickel-titanium (NiTi) rotary systems in the MM canal using 3D printed resin tooth replicas. METHODS: A permanent mandibular first molar with a MM canal was acquired from a pool of extracted teeth and reproduced by a 3D printer. The resin tooth replicas (n = 18) were equally assigned to 3 groups for the evaluation of the shaping abilities of 3 NiTi rotary systems (OneShape [OS], Twisted Files [TF], and ProTaper Gold [PTG]) according to the manufacturer's recommendations. The tooth replicas were scanned by micro-computed tomography (micro-CT) twice before and after instrumentation of the mesiobuccal (MB), mesiolingual (ML), and MM root canals. After 3D reconstruction, the canal straightening, change of root canal volume and surface area, the mesial and distal canal wall thickness and canal transportation at the levels of 1, 2, and 3 mm below furcation were assessed. One-way variance analysis and Turkey's post hoc test were used for comparisons of the means among different groups, and paired-t test was used to compare the mesial and distal sides of the mesial roots. RESULTS: As compared with OS and TF, the use of PTG in preparation of MM canals resulted in significantly more straightening of canal curvature (p < 0.05), greater post-instrumentation canal volume and surface area, and thinner mesial and distal remaining canal wall thickness at 1, 2 and 3 mm below furcation (all p < 0.05). Regarding the root canal transportation in the mesiodistal direction, there was no significant difference among the 3 instruments (all p > 0.05) after the preparation of the MB and ML canals. However, in the MM canal, more pronounced transportation was detected in the PTG group at 2 mm below furcation, and in the TF group at 3 mm below furcation as compared with the other 2 systems (both p < 0.05). CONCLUSIONS: 3D printed tooth replicas have the advantages of consistency and can be an ideal model to evaluate the shaping ability of different instruments in the MM canal. OS and TF files performed similarly and both are appropriate for shaping the MM canal, while PTG may cause excessive and uneven resin removal, especially near the furcation, and may lead to root fragility and procedural errors.

Clinical and electromyographic signals analysis about the effect of space-adjustment splint on overerupted maxillary molars.

BACKGROUND: Overerupted maxillary molars is common in adults, which can lead to insufficient intermaxillary vertical space ,great difficulty in prosthetic reconstruction ,and cause occlusal interference in movements.To reconstruct occlusal function, it is necessary to prepare enough space for prostheses. The aim of the present study was to evaluate the effect of space-adjustment occlusal splint on overerupted maxillary molars by clinical and electromyographic signals analysis. METHODS: Eighteen patients with overerupted maxillary molars were selected to wear space-adjustment occlusal splint suppressing overerupted maxillary molars for three months. Satisfaction was assessed by 5-point Likert; intermaxillary vertical space and the teeth transportation distance were measured in models; clinical periodontal status were evaluated by periodontal probing depth (PPT) and bleeding index (BI); electromyographic recordings of the masseter and anterior temporal muscles were monitored by Cranio-Mandibular K7 Evaluation System. RESULTS: All the patients were satisfied with the treatment effect (Likert scale ≧ 4). The intermaxillary space in edentulous areas after treatment showed statistically significant increasing when compared with those before treatment. PPT and BI showed no significant difference. No statistically significant differences were found in electromyographic activity of anterior temporal muscles, while a reduction of muscle activity in masseter in the contralateral side were detected in post-treatment evaluations compared with pre-treatment at mandibular rest position. CONCLUSIONS: Space-adjustment occlusal splint is an efficient treatment option on overerupted maxillary molars by intruding the maxillary molar to obtain adequate intermaxillary space for prostheses.

Further Interventions after Root Canal Treatment Are Most Common in Molars and Teeth Restored with Direct Restorations: A 10-11-Year Follow-Up of the Adult Swedish Population.

INTRODUCTION: The aims were to investigate 1) the frequency of nonsurgical retreatment, root-end surgery, extraction, and further restorative treatment during a follow-up of 10-11 years after root filling and compare the frequencies according to tooth group and type of coronal restoration and 2) the timing of nonsurgical retreatment, root-end surgery, and extraction. METHODS: Data were collected from the Swedish Social Insurance Agency's register. A search for treatment codes identified teeth root filled in 2009 and the type of coronal restoration (direct, indirect, and unspecified) registered within 6 months of root filling. The root-filled teeth were followed 10-11 years, and further interventions were recorded. Descriptive statistics and chi-square tests were used for statistical analysis. RESULTS: In 2009, root fillings were registered for 215,611 individuals/teeth. Nonsurgical retreatment, root-end surgery, and extraction were undertaken in 3.5%, 1.4%, and 20% teeth, respectively. The frequency of further interventions varied with respect to tooth group and type of coronal restoration, but only slightly for endodontic retreatments. Further interventions, except for root-end surgery, were registered more often for molars and directly restored teeth (P < .001). The majority of endodontic retreatments were undertaken within 4 years, while extractions were evenly distributed over 10-11 years. CONCLUSIONS: The frequency numbers of nonsurgical retreatment and root-end surgery were low, despite 1 in 5 root-filled teeth registered as extracted. Further interventions were most common in molars and directly restored teeth. Endodontic retreatments were performed more often during the first 4 years.

Comparative evaluation of cervical pulpotomy and pulpectomy for primary molars with irreversible pulpitis: a multicentre randomised controlled trial.

PURPOSE: The objective of this multicentre randomised controlled trial was to compare the clinical/radiographic outcomes of cervical pulpotomy using calcium-enriched mixture cement (PCEM) and pulpectomy using Metapex (PM) in primary molars with irreversible pulpitis (IP). METHODS: A total of 134 primary molars from 94 children were randomly assigned to two intervention groups: the PCEM group (n = 74) and the PM group (n = 60). Baseline characteristics including age/gender/molar type/tooth type/jaw were recorded. The primary outcome measures were clinical/radiographic success rates assessed at the first and second follow-up appointments. Secondary outcomes included reasons for clinical/radiographic failures. Multiple logistic regression analysis was performed to determine the impact of various factors on the success rates. RESULTS: The mean age of the participants in both groups was similar (PCEM group: 5.4 years, PM group: 5.5 years). Gender distribution, molar type, tooth type, jaw, and number of practitioners were comparable between the groups. The clinical success rate at the first follow-up was 98.6% in the PCEM group and 96.4% in the PM group. At the second follow-up, the clinical success rate was 97.1% in the PCEM group and 91.1% in the PM group. The radiographic success rates at the first and second follow-up were 98.6% and 96.4% in the PCEM group and 96.4% and 91.1% in the PM group, respectively. Multiple logistic regression analysis did not reveal any significant association between the success rates and age/gender/molar type/jaw, or treatment groups (P > 0.05). CONCLUSION: In primary molars with IP, both simple/conservative cervical pulpotomy using calcium-enriched mixture cement and pulpectomy using Metapex demonstrated high clinical/radiographic success rates. No significant differences were observed between the two treatment modalities. These findings suggest that both techniques can be considered effective treatment options for managing primary molars with IP. TRIAL REGISTRATION NUMBER: Trial registration number: IRCT20201226049838N1, retrospectively registered on 12 January 2021.